100275091_2000533998_Rev K
™
FIRE TUBE COMBI
Fire Tube Combi Boiler
Installation & Service Manual
Models: 110 - 199
WARNING
This manual must only be used
by a qualified heating installer
/ service technician. Read all
instructions, in this manual before
installing. Perform steps in the
order given. Failure to comply
could result in severe personal
injury, death, or substantial
property damage.
Save this manual for future reference.
Contents
HAZARD DEFINITIONS................................................................. 2
PLEASE READ BEFORE PROCEEDING .............................. 3
THE NOBLE COMBI BOILER -- HOW IT WORKS .............. 4-5
RATINGS ............................................................................................ 6
1. DETERMINE BOILER LOCATION
Provide Clearances .............................................................................. 7
Provide Air Openings to Room ......................................................... 9
Wall Mounting Location ................................................................... 9
Residential Garage Installation .......................................................... 9
Vent and Air Piping ............................................................................ 9
Prevent Combustion Air Contamination ........................................ 9
Corrosive Contaminants and Sources ............................................ 10
Using an Existing Vent System to Install a New Boiler ............... 10
Removing a Boiler from Existing Common Vent ........................ 11
2. PREPARE BOILER
Remove Boiler from Wood Pallet ................................................... 12
Gas Conversions .......................................................................... 12-13
Mounting the Boiler .......................................................................... 13
3. GENERAL VENTING
Direct Venting Options .................................................................... 14
Install Vent and Combustion Air Piping ....................................... 15
Sizing ................................................................................................... 16
Max. Allowable Vent Piping Lengths ............................................. 16
Materials .............................................................................................. 16
Optional Room Air............................................................................ 17
PVC/CPVC ......................................................................................... 18
Polypropylene......................................................................................19
Stainless Steel Vent ............................................................................ 20
4. SIDEWALL DIRECT VENTING
Vent/Air Termination - Sidewall .............................................. 21-23
Determine Location ............................................................... 21-22
Prepare Wall Penetrations .......................................................... 23
Multiple Vent/Air Terminations ..................................................... 23
Sidewall Termination - Optional Concentric Vent ................ 24-26
5. VERTICAL DIRECT VENTING
Vent/Air Termination - Vertical ............................................... 27-28
Determine Location ..................................................................... 27
Prepare Roof Penetrations .......................................................... 28
Multiple Vent/Air Terminations ..................................................... 28
Vertical Termination - Optional Concentric Vent................. 29-30
Alternate Vertical Concentric Venting .................................... 31-32
6A. HYDRONIC PIPING
System Water Piping Methods ........................................................ 33
Low Water Cutoff Device ................................................................. 33
Chilled Water System........................................................................ 33
Freeze Protection ............................................................................... 33
General Piping Information ............................................................. 33
Near Boiler Piping Components ..................................................... 34
Hydronic Piping Diagrams ......................................................... 36-39
6B. DOMESTIC WATER PIPING
Scalding ............................................................................................... 40
Water Chemistry................................................................................ 40
Near Heater Piping Components .................................................... 40
Domestic Water Piping Diagrams ............................................ 41-43
7. GAS CONNECTIONS
Connecting Gas Supply Piping ........................................................ 44
Natural Gas ......................................................................................... 45
Pipe Sizing for Natural Gas ........................................................ 45
Natural Gas Supply Pressure Requirements ............................ 45
Propane Gas........................................................................................ 45
Pipe Sizing for Propane Gas ....................................................... 45
Propane Supply Pressure Requirements ................................... 45
Check Inlet Gas Supply ............................................................... 46-47
Gas Pressure ....................................................................................... 47
Gas Valve Replacement .................................................................... 47
8. FIELD WIRING
Line Voltage Connections ................................................................ 48
Low Voltage Connections ................................................................ 48
9. CONDENSATE DISPOSAL
Condensate Drain .............................................................................. 51
10. STARTUP ............................................................................ 52-60
11. OPERATING INFORMATION
General ................................................................................................ 61
Menus ............................................................................................. 61-62
Control Inputs and Outputs ....................................................... 63-64
Cascade .................................................................................................65
Protection Features....................................................................... 65-66
Sequence of Operation ................................................................ 66-68
12. MAINTENANCE
Maintenance and Annual Startup ............................................. 69-75
13. TROUBLESHOOTING .................................................... 76-87
14. DIAGRAMS
Ladder Diagram (Standard) ............................................................. 88
Wiring Diagram (Standard) ............................................................. 89
Revision Notes.................................................................... Back Cover
Hazard definitions
The following defined terms are used throughout this manual to bring attention to the presence of hazards of various risk levels or
to important information concerning the life of the product.
DANGER indicates an imminently hazardous situation which, if not avoided, will result in death or serious
DANGER injury.
WARNING indicates a potentially hazardous situation which, if not avoided, could result in death or serious
WARNING injury.
CAUTION indicates a potentially hazardous situation which, if not avoided, may result in minor or moderate
CAUTION injury.
CAUTION
NOTICE
2
CAUTION used without the safety alert symbol indicates a potentially hazardous situation which, if not
avoided, may result in property damage.
NOTICE indicates special instructions on installation, operation, or maintenance that are important but not
related to personal injury or property damage.
™
FIRE TUBE COMBI
Installation & Service Manual
Please read before proceeding
WARNING
Installer – Read all instructions, in this
manual before installing. Perform steps
in the order given.
User – This manual is for use only
by a qualified heating installer/
service technician. Refer to the User’s
Information Manual for your reference.
Have this boiler serviced/inspected by
a qualified service technician, at least
annually.
Failure to comply with the above could
result in severe personal injury, death or
substantial property damage.
NOTICE
When calling or writing about the boiler
– Please have the boiler model and serial
number from the boiler rating plate.
WARNING
DO NOT install units in rooms or
environments that contain corrosive
contaminants (see Table 1A on page 10).
Failure to comply could result in severe
personal injury, death, or substantial
property damage.
When servicing boiler –
• To avoid electric shock, disconnect electrical supply
before performing maintenance.
• To avoid severe burns, allow boiler to cool before
performing maintenance.
Boiler operation –
• Do not block flow of combustion or ventilation air to
the boiler.
Consider piping and installation when
determining boiler location.
• Should overheating occur or gas supply fail to shut off,
do not turn off or disconnect electrical supply to
circulator. Instead, shut off the gas supply at a location
external to the appliance.
Any claims for damage or shortage in
shipment must be filed immediately
against the transportation company by
the consignee.
• Do not use this boiler if any part has been under water.
The possible damage to a flooded appliance can be
extensive and present numerous safety hazards. Any
appliance that has been under water must be replaced.
Factory warranty (shipped with unit) does
not apply to units improperly installed or
improperly operated.
WARNING
Failure to adhere to the guidelines on this
page can result in severe personal injury,
death, or substantial property damage.
WARNING
If the information in this manual is not
followed exactly, a fire or explosion may
result causing property damage, personal
injury or loss of life.
This appliance MUST NOT be installed in
any location where gasoline or flammable
vapors are likely to be present.
WHAT TO DO IF YOU SMELL GAS
Boiler water –
• Thoroughly flush the system to remove debris. Use
an approved pre-commissioning cleaner (see Start-Up
Section), without the boiler connected, to clean the
system and remove sediment. The high efficiency heat
exchanger can be damaged by build-up or corrosion
due to sediment.
NOTE: Cleaners are designed for either new systems or
pre-existing systems. Choose accordingly.
Freeze protection fluids –
• NEVER use automotive antifreeze. Use only inhibited
propylene glycol solutions, which are specifically
formulated for hydronic systems. Ethylene glycol is
toxic and can attack gaskets and seals used in hydronic
systems.
• Do not try to light any appliance.
• Do not touch any electric switch; do
not use any phone in your building.
• Immediately call your gas supplier
from a near by phone. Follow the
gas supplier’s instructions.
• If you cannot reach your gas supplier,
call the fire department.
• Installation and service must be
performed by a qualified installer,
service agency, or the gas supplier.
3
™
FIRE TUBE COMBI
Installation & Service Manual
The Noble Combi Boiler - How it works...
1.
Heat exchanger
Allows system water to flow through specially designed
coils for maximum heat transfer, while providing
protection against flue gas corrosion.
The coils are
encased in a jacket that contains the combustion process.
2.
Blower
The blower pulls in air and gas through the venturi (item
5). Air and gas mix inside the blower and are pushed into the
burner, where they burn inside the combustion chamber.
3.
Gas valve
The gas valve senses the negative pressure created by the
blower, allowing gas to flow only if the gas valve is
powered and combustion air is flowing.
4.
Venturi
The venturi controls air and gas flow into the burner.
5.
Flue gas sensor (limit rated)
This sensor monitors the flue gas exit temperature. The control
module will modulate and shut down the boiler if flue gas
temperature gets too hot. This protects the flue pipe from
overheating.
6.
7.
Boiler outlet temperature sensor (limit rated)
17. Boiler control module
The boiler control responds to internal and external signals
and controls the blower, gas valve, and pumps to meet the
demand.
18. Air intake adapter
Allows for the connection of the air intake pipe to
the boiler.
19. High voltage junction box
The junction box contains the connection points for the line
voltage power and all pumps.
20. Low voltage connection board
The connection board is used to connect external low voltage
devices.
21. Low voltage wiring connections
Conduit connection
connection board.
points
22. Condensate drain connection
Boiler inlet temperature sensor
23. Front access cover
Temperature and pressure gauge (field installed, not
shown)
Monitors the outlet temperature of the boiler as well as the
system water pressure.
9.
Threaded pipe connection of 1/2". This pipe should be
connected to the incoming gas supply for the purpose of
delivering gas to the boiler.
This sensor monitors boiler outlet water temperature (system
supply). The control module will adjust boiler firing rate so the
outlet temperature is correct.
This sensor monitors return water temperature (system
return).
8.
16. Gas connection pipe
Electronic LCD display
The electronic display consists of five (5) buttons, and a liquid
crystal display. The display is used to make adjustments and
read boiler status.
10. Flue pipe adapter
Allows for the connection of the vent pipe system to the
boiler.
11. Burner (not shown)
Made with metal fiber and stainless steel construction,
the burner uses pre-mixed air and gas and provides a
wide range of firing rates.
12. Boiler water outlet
The boiler water outlet is the boiler water connection for water
leaving the boiler and entering the system.
13. DHW water outlet
The DHW water outlet is the DHW water connection for water
leaving the boiler and entering the system.
14. Boiler water inlet
The boiler water inlet is the boiler water connection for water
entering the boiler from the system.
15. DHW water inlet
The DHW water inlet is the DHW water connection for water
entering the boiler from the system.
4
for
the
low
voltage
The condensate drain connection provides a connection
point to install a condensate drain line.
Provides access to all internal components.
24. Ignition / flame sense electrode
Used by the control module to detect the presence of burner
flame.
25. Flame inspection window
The quartz glass window provides a view of the burner
surface and flame.
26. Relief valve
Protects the heat exchanger from an over pressure condition.
The relief valve provided with the unit is set at 50 psi.
27. Line voltage wiring connections (inside junction box)
Conduit connection points for the high voltage junction box.
28. Air pressure switch
The air pressure switch detects blocked conditions.
29. Transformer
The transformer provides 24V power to the integrated control.
30. Pump with automatic air vent
Provides flow through the unit for space heating and domestic
water applications. Serves as the boiler and DHW pump.
31. Diverter valve
Diverts boiler water from the heating loop to the DHW heat
exchanger.
32. Flow switch
The flow switch detects a DHW draw, and signals the
boiler to fire.
33. DHW sensor
This sensor monitors DHW water temperature.
The control module will adjust boiler firing rate so the
DHW temperature is correct.
™
FIRE TUBE COMBI
Installation & Service Manual
The Noble Combi Boiler - How it works...
10
18
(continued)
13
12
26
2
16
21
FRONT
23
15
14
LEFT
9
RIGHT
19
DIR #2000528036 00
BACK
22
DIR #2000528036
Bottom View
Front Outside View
4
3
25
28
5
20
28
24
1
29
17
30
32
6
7
27
33
DIR #2000528036 00
31
DIR #2000528036 00
Front Inside View
Side_Rear View
5
Installation & Service Manual
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FIRE TUBE COMBI
Ratings
A
S
M
E
H
LOW LEAD CONTENT
Combi
AHRI Rating
Model Number
Note: Change “N”
to “L” for L.P. gas
models.
Input
MBH
(Note 5)
Other Specifications
Heating
Capacity
MBH
Net
AHRI
Ratings
Water,
MBH
AFUE
%
Boiler Water
SH Water
Content Gallons Connections
DHW Water
Connections
Gas
Connections
Vent/Air
Size
(Note 4)
Min
Max
(Note 2, 7)
(Note 3, 7)
(Note 1, 7)
NKC110(N,L)
11
110
102
89
95.0
1.4
1"
3/4"
1/2"
3"
NKC150(N,L)
15
150
139
121
95.0
2.0
1"
3/4"
1/2"
3"
NKC199(N,L)
20
199
185
161
95.0
2.7
1"
3/4"
1/2"
3"
NOTICE
Maximum allowed working pressure is located on the rating plate.
Notes:
1. As an Energy Star Partner, the manufacturer has determined
that Noble Combi Boilers meet the Energy Star guidelines
for energy efficiency.
2. The ratings are based on standard test procedures prescribed
by the United States Department of Energy.
3. Net AHRI ratings are based on net installed radiation of
sufficient quantity for the requirements of the building
and nothing need be added for normal piping and pickup.
Ratings are based on a piping and pickup allowance of 1.15.
4. Noble Combi Boilers require special gas venting. Use only
the vent materials and methods specified in the Noble
Combi Boiler Installation and Service Manual.
7. Ratings have been confirmed by the Hydronics Institute,
Section of AHRI.
8. The manual reset high limit provided with the NKC is
listed to UL353.
UNIT EQUIPPED FOR
HIGH ALTITUDE
3,000 FT. TO 9,600 FT.
5. Standard Noble Combi Boilers are equipped to operate from
sea level to 4,500 feet only with no adjustments. The boiler
will de-rate by 4% for each 1,000 feet above sea level up to
4,500 feet.
6. High altitude Noble Combi Boilers are equipped to operate
from 3,000 to 9,600 feet. The boiler will de-rate 1.7%
between 5,000 to 9,600 feet. For any units installed past
9,600 feet there is an additional de-rate of 4% per 1,000 feet
beyond 9,600 feet per the National Fuel Gas Code. Boilers
configured for high altitude shall not be installed below 3000
feet.
The operation given in this manual remains the same as the
standard boilers. A high altitude label (as shown in FIG. A)
is also affixed to the unit.
De-rate values are based on proper combustion calibration
and CO2’s adjusted to the recommended levels.
For installations above 9,600 feet, please consult the factory.
6
Figure A High Altitude Label Location
™
FIRE TUBE COMBI
1
Determine boiler location
Installation must comply with:
• Local, state, provincial, and national codes, laws,
regulations, and ordinances.
• National Fuel Gas Code, ANSI Z223.1 – latest edition.
• National Electrical Code.
• For Canada only: B149.1 Installation Code, CSA C22.1
Canadian Electrical Code Part 1 and any local codes.
NOTICE
The Noble Combi Boiler gas manifold
and controls met safe lighting and other
performance criteria when the boiler
underwent tests specified in ANSI Z21.13
– latest edition.
Before locating the boiler, check:
1.
2.
3.
Installation & Service Manual
Check for nearby connection to:
• System water piping
• Venting connections
• Gas supply piping
• Electrical power
Locate the appliance so that if water connections should
leak, water damage will not occur. When such locations
cannot be avoided, it is recommended that a suitable
drain pan, adequately drained, be installed under the
appliance. The pan must not restrict combustion air
flow. Under no circumstances is the manufacturer to be
held responsible for water damage in connection with
this appliance, or any of its components.
Check area around the boiler. Remove any combustible
materials, gasoline and other flammable liquids.
Failure to keep boiler area clear and free
WARNING of combustible materials, gasoline, and
other flammable liquids and vapors can
result in severe personal injury, death, or
substantial property damage.
4. The Noble Combi Boiler must be installed so that gas
control system components are protected from dripping
or spraying water or rain during operation or service.
5. If a new boiler will replace an existing boiler, check for
and correct system problems, such as:
• System leaks causing oxygen corrosion or heat
exchanger cracks from hard water deposits.
• Incorrectly-sized expansion tank.
• Lack of freeze protection in boiler water causing system
and boiler to freeze and leak.
• Debris left from existing piping, if not flushed and
cleaned with an appropriate cleaner.
6.
Check around the boiler for any potential air
contaminants that could risk corrosion to the boiler or
the boiler combustion air supply (see Table 1A on page
10). Prevent combustion air contamination. Remove
any of these contaminants from the boiler area.
DO NOT install units in rooms or
WARNING environments that contain corrosive
contaminants (see Table 1A on page 10).
Failure to comply could result in severe
personal injury, death, or substantial
property damage.
WARNING
This appliance is certified as an indoor
appliance. Do not install the appliance
outdoors or locate where the appliance will
be exposed to freezing temperatures or to
temperatures that exceed 100°F.
Failure to install the appliance indoors
could result in severe personal injury,
death, or substantial property damage.
This appliance requires a special venting
WARNING system. The vent connection to the
appliance is made of CPVC. Field supplied
vent fittings must be cemented to the CPVC
fitting on the boiler. Use only the vent
materials, primer, and cement specified in
the manual to make the vent connections.
Failure to follow this warning could result
in fire, personal injury, or death.
Closet and alcove installations
A closet is any room the boiler is installed in which is less
than 93 cubic feet for NKC110 models, and 102 cubic feet for
NKC150 - 199 models.
An alcove is any room which meets the criteria for a closet
with the exception that it does not have a door.
Example: Room dimensions = 4 feet long, 3 feet wide, and
7 foot ceiling = 4 x 3 x 7 = 84 cubic feet. This would be
considered a closet for a Noble Combi Boiler.
WARNING
For closet and alcove installations as
shown in FIG.’s 1-1 and 1-2, CPVC,
polypropylene or stainless steel vent
material must be used inside the structure.
The two ventilating air openings shown in
FIG. 1-1 are required for this arrangement.
Failure to follow this warning could result
in fire, personal injury, or death.
Provide clearances:
Clearances from combustible materials
1. Hot water pipes—at least 1/4" from combustible materials.
2. Vent pipe – at least 1" from combustible materials.
3. See FIG.’s 1-1 and 1-2 on page 8 for other clearance
minimums.
Clearances for service access
1. See page 9 for recommended service clearances. If you
do not provide the minimum clearances shown, it may
not be possible to service the boiler without removing it
from the space.
7
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FIRE TUBE COMBI
1
Installation & Service Manual
Determine boiler location
Figure 1-1 Closet Installation - Minimum Required Clearances
1" MINIMUM CLEARANCE
AROUND VENT PIPE
For closet installations, CPVC,
WARNING polypropylene, or stainless steel
vent material MUST BE used in
a closet structure due to elevated
temperatures. Failure to follow
this warning could result in fire,
personal injury, or death.
TOP
6"
MINIMUM
LEFT
0"
MINIMUM
6"
Minimum Clearances to Combustible
Materials
Location
Clearances
From Top of the Unit
6"
From Front of the Unit
6"
From Flue or Vent Connector
1"
in any Direction
VENTING*
OPENING
6"
From Back of the Unit
0"
From the Left Side of the Unit
0"
From the Right Side of the Unit
0"
Type of Floor - Combustible
BOTTOM
0"
MINIMUM
1/4"MINIMUM CLEARANCE
AROUND HOT WATER PIPES
FRONT
6"
MINIMUM
VENTING*
OPENING
DIR #2000534543 00
Note: Service clearances are recommendations only.
Figure 1-2 Alcove Installation - Minimum Required Clearances
1" MINIMUM CLEARANCE
AROUND VENT PIPE
TOP
6"
MINIMUM
LEFT
0"
MINIMUM
RIGHT
0" MINIMUM
OPEN DOOR
BOTTOM
0"
MINIMUM
1/4"MINIMUM CLEARANCE
AROUND HOT WATER PIPES
FRONT
6"
MINIMUM
Note: Service clearances are recommendations only.
8
DIR #2000534544 00
WARNING For alcove installations, CPVC,
polypropylene, or stainless steel
vent material MUST BE used in
an alcove structure due to elevated
temperatures. Failure to follow
this warning could result in fire,
personal injury, or death.
™
FIRE TUBE COMBI
1
Determine boiler location
NOTICE
If you do not provide the recommended
service clearances shown, it may not be
possible to service the boiler without
removing it from the space.
Recommended clearances for service access
- Front ............................................................................. 24"
- Left ................................................................................ 12"
- Right ............................................................................. 12"
- Bottom .......................................................................... 24"
Provide air openings to room:
Boiler alone in boiler room
1. No air ventilation openings into the boiler room are
needed when clearances around the Noble Combi
Boiler are at least equal to the SERVICE clearances
shown in FIG.’s 1-1 and 1-2. For spaces that do NOT
supply this clearance, provide two openings as shown
in FIG. 1-1. Each opening must provide one square
inch free area per 1,000 Btu/hr of boiler input.
Boiler in same space with other gas or oil-fired
appliances
1. Follow the National Fuel Gas Code (U.S.) or CSA
B149.1 (Canada) to size/verify size of the combustion/
ventilation air openings into the space.
WARNING
The space must be provided with
combustion/ventilation air openings
correctly sized for all other appliances
located in the same space as the Noble
Combi Boiler.
Do not install the boiler in an attic.
Failure to comply with the above
warnings could result in severe personal
injury, death, or substantial property
damage.
2. Size openings only on the basis of the other appliances
in the space. No additional air opening free area is
needed for the Noble Combi Boiler because it takes its
combustion air from outside (direct vent installation).
(continued)
Residential garage installation
Precautions
Take the following precautions when installing the appliance in
a residential garage. If the appliance is located in a residential
garage, it should be installed in compliance with the latest
edition of the National Fuel Gas Code, ANSI Z223.1 and/or
CAN/CGA-B149 Installation Code.
• Appliances located in residential garages and in
adjacent spaces that open to the garage and are not part
of the living space of a dwelling shall be installed so that
all burners and burner ignition devices are located not
less than 18 inches (46 cm) above the floor.
• The appliance shall be located or protected so that it is
not subject to physical damage by a moving vehicle.
Vent and air piping
The Noble Combi Boiler requires a special vent system, designed
for pressurized venting.
The boiler is to be used for either direct vent installation or for
installation using indoor combustion air. When room air is
considered, see Section 3, General Venting. Note prevention of
combustion air contamination below when considering vent/
air termination.
Vent and air must terminate near one another and may be
vented vertically through the roof or out a side wall, unless
otherwise specified. You may use any of the vent/air piping
methods covered in this manual. Do not attempt to install the
Noble Combi Boiler using any other means.
Be sure to locate the boiler such that the vent and air piping can
be routed through the building and properly terminated. The
vent/air piping lengths, routing and termination method must
all comply with the methods and limits given in this manual.
Prevent combustion air contamination
Install air inlet piping for the Noble Combi Boiler as described
in this manual. Do not terminate vent/air in locations that can
allow contamination of combustion air. Refer to Table 1A,
page 10 for products and areas which may cause contaminated
combustion air.
WARNING
Wall mounting location
Ensure the wall for which the boiler is intended to be
mounted is comprised of either, cement, brick, block, or
wooden studs spaced 16" apart from center. Ensure the
wall is capable of supporting at least 200 pounds.
If flooding is possible, elevate the boiler sufficiently to
prevent water from reaching the boiler.
Ensure the boiler is installed in a location that minimizes
the risk of water damage due to valves, pumps, etc.
Installation & Service Manual
You must pipe combustion air to the boiler
air intake. Ensure that the combustion air will
not contain any of the contaminants in Table
1A, page 10. Contaminated combustion air
will damage the boiler, resulting in possible
severe personal injury, death or substantial
property damage. Do not pipe combustion
air near a swimming pool, for example.
Also, avoid areas subject to exhaust fumes
from laundry facilities. These areas will
always contain contaminants.
9
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FIRE TUBE COMBI
1
Installation & Service Manual
Determine boiler location
Table 1A Corrosive Contaminants and Sources
Products to avoid:
Spray cans containing chloro/fluorocarbons
Permanent wave solutions
Chlorinated waxes/cleaners
Chlorine-based swimming pool chemicals
Calcium chloride used for thawing
Sodium chloride used for water softening
Refrigerant leaks
Paint or varnish removers
Hydrochloric acid/muriatic acid
Cements and glues
Antistatic fabric softeners used in clothes dryers
Chlorine-type bleaches, detergents, and cleaning solvents
found in household laundry rooms
Adhesives used to fasten building products and other
similar products
Areas likely to have contaminants
Dry cleaning/laundry areas and establishments
Swimming pools
Metal fabrication plants
Beauty shops
Refrigeration repair shops
Photo processing plants
Auto body shops
Plastic manufacturing plants
Furniture refinishing areas and establishments
New building construction
Remodeling areas
Garages with workshops
10
When using an existing vent system to
install a new boiler:
Failure to follow all instructions can result
WARNING in flue gas spillage and carbon monoxide
emissions, causing severe personal injury
or death.
Check the following venting components before installing:
• Material - For materials listed for use with this appliance,
see Section 3 - General Venting.
• Size - To ensure proper pipe size is in place, see Table 3A.
Check to see that this size is used throughout the vent
system.
• Manufacturer - For a polypropylene or stainless steel
application, you must use only the listed manufacturers
and their type product listed in Tables 3D and 3F for CAT
IV positive pressure venting with flue producing
condensate.
• Supports - Non-combustible supports must be in place
allowing a minimum 1/4" rise per foot. The supports
should adequately prevent sagging and vertical slippage,
by distributing the vent system weight. For additional
information, consult the vent manufacturer’s
instructions for installation.
• Terminations - Carefully review Sections 3 through 5 to
ensure requirements for the location of the vent and air
terminations are met and orientation of these fit the
appropriate image from the Sidewall or Vertical
options listed in the General Venting Section. For
stainless steel vent, only use terminations listed in Table
3B for the manufacturer of the installed vent.
• Seal - With prior requirements met, the system should be
tested to the procedure listed in parts (c) through (f) of
the Removal of an Existing Boiler Section on page 11.
With polypropylene and stainless steel vent, seal and connect
all pipe and components as specified by the vent manufacturer
used; with PVC/CPVC vent, see the Installing Vent or Air
Piping Section on page 18.
If any of these conditions are not met,
WARNING the existing system must be updated or
replaced for that concern. Failure to
follow all instructions can result in flue gas
spillage and carbon monoxide emissions,
causing severe personal injury or death.
™
FIRE TUBE COMBI
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Determine boiler location
Installation & Service Manual
(continued)
When removing a boiler from existing common vent system:
DANGER
Do not install the Noble Combi Boiler into
a common vent with any other appliance.
This will cause flue gas spillage or appliance
malfunction, resulting in possible severe
personal injury, death, or substantial
property damage.
Failure to follow all instructions can result
WARNING in flue gas spillage and carbon monoxide
emissions, causing severe personal injury
or death.
g. Any improper operation of the common venting system
should be corrected so the installation conforms with
the National Fuel Gas Code, ANSI Z223.1/NFPA 54
and/or CAN/CSA B149.1, Natural Gas and Propane
Installation Code. When resizing any portion of the
common venting system, the common venting system
should be resized to approach the minimum size as
determined using the appropriate tables in Part 11
of the National Fuel Gas Code, ANSI Z223.1/NFPA
and/or CAN/CSA B149.1, Natural Gas and Propane
Installation Code.
At the time of removal of an existing boiler, the following steps
shall be followed with each appliance remaining connected
to the common venting system placed in operation, while the
other appliances remaining connected to the common venting
system are not in operation.
a. Seal any unused openings in the common venting system.
b. Visually inspect the venting system for proper size and
horizontal pitch and determine there is no blockage or
restriction, leakage, corrosion, or other deficiencies, which
could cause an unsafe condition.
c.
Test vent system – Insofar as is practical, close all building
doors and windows and all doors between the space in
which the appliances remaining connected to the common
venting system are located and other spaces of the building.
Turn on clothes dryers and any appliance not connected
to the common venting system. Turn on any exhaust fans,
such as range hoods and bathroom exhausts, so they will
operate at maximum speed. Do not operate a summer
exhaust fan. Close fireplace dampers.
d. Place in operation the appliance being inspected. Follow
the lighting instructions. Adjust thermostat so appliance
will operate continuously.
e.
Test for spillage at the draft hood relief opening after
5 minutes of main burner operation. Use the flame of a
match or candle, or smoke from a cigarette, cigar, or pipe.
f.
After it has been determined that each appliance remaining
connected to the common venting system properly vents
when tested as outlined herein, return doors, windows,
exhaust fans, fireplace dampers, and any other gas-burning
appliance to their previous conditions of use.
11
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FIRE TUBE COMBI
2
Installation & Service Manual
Prepare boiler
Remove boiler from wood pallet
1. After removing the outer shipping carton from the
boiler, remove the parts box.
2. To remove the boiler from the pallet:
a. Remove the two (2) lag bolts securing the
bottom of the unit to the pallet.
b. Lift the boiler off the wall bracket mounted to
the pallet (FIG. 2-1).
CAUTION
Do not attempt to use the water pipe
fittings or gas pipe to lift the boiler.
CAUTION
Do not attempt to lift the boiler using the
gas pipe as a handle.
Figure 2-1 Boiler Mounted on Shipping Pallet
REMOVE SHIPPING
(WALL) BRACKET
DO NOT DISCARD.
WILL BE NEEDED TO
SECURE THE BOILER
TO THE WALL.
DIR #2000528206 00
3. Remove the two (2) lag bolts securing the wall bracket to the
wood pallet. Be certain not to lose the wall bracket as it will
be needed for securing the boiler to the wall (FIG. 2-4).
Do not drop the boiler. Damage to the
NOTICE
boiler can result.
Gas conversions
For a boiler already installed, you must
WARNING turn off gas supply, turn off power and
allow boiler to cool before proceeding.
You must also completely test the boiler
after conversion to verify performance as
described under Start-up, Section 10 of
this manual.
Failure to comply could result in severe
personal injury, death, or substantial
property damage.
1. If boiler is already installed, you must turn off the gas
supply, turn off the power, and allow the boiler to cool
before proceeding.
2. Remove the front access cover from the unit (no tools
required for removal).
3. Using a 5/16" nut driver, loosen the rachet clamp securing
the air intake fitting to the venturi assembly. Slide the
rubber boot off the venturi.
4. Using an adjustable wrench, loosen the union between the
gas valve adapter and the venturi assembly. Remove the
gasket between the gas piping and venturi (FIG. 2-2).
5. Using a 3 mm Allen wrench, remove the three (3) screws
securing the venturi to the fan assembly and proceed to
remove the natural gas venturi from the unit, making sure
not to damage the blower O-ring gasket (FIG. 2-2).
6. Install the air shutter (reference Table 2A for the model
specific air shutter to be installed).
a. Disconnect the wiring from the fan and remove the
bolts securing the fan to the heat exchanger top plate.
b. Remove the fan and gasket, and install the air shutter
provided in the kit. Note: On NKC110 models, the air
shutter MUST be installed in the proper direction.
Install the air shutter so that the hole in the corner is
oriented towards the back right corner of the unit
(opposite the front door and gas piping).
c. Replace all torn or damaged gaskets. Reassemble the
fan assembly and reconnect the wiring harnesses
before operation.
7. Install the propane venturi and verify the following:
a. The UP arrow on the plastic housing is pointing
upward.
b. The threaded connection for the gas piping is facing
towards the LEFT of the unit.
8. Reassemble the unit by following the previous steps in
reverse order, taking care to ensure that the venturi adapter
gasket is seated properly before tightening the nut on the
venturi. NOTE: Replace any torn or damaged gasket(s) that
may have been damaged or torn during installation.
9. After installation is complete, fill out the gas conversion
label (in the conversion kit bag) and affix it to the unit to the
right of the control display as shown in FIG. 2-3.
10. Replace the front access cover removed in Step 2 and
resume operation.
DANGER
You must install a propane venturi to operate the Noble
Combi Boiler on propane gas. Verify when installing that the
venturi label marking matches the boiler size (see Table 2A).
Table 2A LP Conversion Table
Model
110
150
199
12
Orifice Ø
Venturi Ø
(mm)
Bottom
Top
100275546
20 mm 2.45 mm 2.55 mm
100275548
24 mm 3.20 mm 2.95 mm
100275549
22 mm 3.30 mm 3.10 mm
Kit #
Air
Shutter
100275611
100275613
100275615
When removing the natural gas venturi,
inspect the gasket at the gas connection
and the O-ring at the blower. These
gaskets must be in good condition and
must be installed. Failure to comply
will cause a gas leak, resulting in severe
personal injury or death.
™
FIRE TUBE COMBI
2
Prepare boiler
WARNING
(continued)
After converting to LP, check combustion
per the Start-up procedure in Section 10
of this manual. Failure to check and
verify combustion could result in severe
personal injury, death, or substantial
property damage.
NATURAL GAS
VENTURI
AIR SHUTTER
DIR #2000534767 00
Figure 2-3 Gas Conversion Label Location
2.
Mount the wall bracket using the 2 1/4" lag bolts
provided. Make sure the top edge of the bracket is away
from the wall. Ensure the bracket is level when mounted.
Extreme care is needed to ensure the bolts are secured in
the center of the studs.
3.
Hang the boiler on the bracket and secure the bottom of
the boiler with two (2) additional lag bolts provided.
WARNING The boiler is too heavy for a single person
to lift. A minimum of two people is
needed for mounting the boiler onto the
bracket.
Figure 2-2 Remove Natural Gas Venturi
DISCONNECT
GAS PIPING
Installation & Service Manual
Mounting to a concrete wall:
1. Mount the wall bracket using the two (2) wedge anchor
bolts provided with the bracket (FIG. 2-4). To mount the
wedge anchor bolts, drill a 1/4" diameter hole 1 1/8" deep
and insert anchor. Hang the bracket from the anchor and
secure with the two nuts provided. Make sure the top edge
of the bracket is away from the wall. Ensure bracket is level
when mounted.
Note: If wall thickness does not allow a 1 1/8" deep hole,
field supplied hardware suitable for the application should be
provided.
2. Hang the boiler on the bracket and secure the bottom of the
boiler with two (2) remaining anchors, following the
instructions above.
Mounting to a metal studded wall:
1. The wall mount bracket is designed for a stud spacing of 16
inches from center (FIG. 2-4). For other stud spacing a
solid mounting surface must be provided by the installer.
Do not mount the boiler to a hollow wall. Be
sure to mount the boiler to the studs only.
Mount the wall bracket using two (2) field supplied toggle
bolts capable of supporting 100 pounds each. Ensure the
top edge of the bracket is away from the wall. Ensure the
bracket is level when mounted. Extreme care is needed to
ensure the bolts are secured in the center of the studs.
Hang the boiler on the bracket and secure the bottom of the
boiler with two (2) field supplied toggle bolts.
WARNING
GAS CONVERSION LABEL
(AFFIX TO UNIT AS SHOWN)
2.
3.
DIR #2000536093 00
Figure 2-4 Mounting the boiler
Mounting the boiler
See page 9 of this manual for boiler mounting location
instructions.
The Noble Combi Boiler is not intended
NOTICE
for floor installation.
WALL:
WOOD OR METAL STUDS
ON 16" CENTERS -ORMASONRY / POURED CONCRETE
MOUNTING BRACKET
(FACTORY SUPPLIED)
Mounting to a wood studded wall:
1.
The wall mount bracket is designed for a stud spacing of
16 inches from center (FIG. 2-4). For other stud spacing
a solid mounting surface must be provided by the
installer.
WARNING Do not mount the boiler to a hollow wall.
Be sure to mount the boiler to the studs
only.
FASTENERS
APPROPRIATE
FOR WALL TYPE
QTY: 4
DIR #2000528235 00
13
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FIRE TUBE COMBI
3
Installation & Service Manual
General venting
Direct venting options - Sidewall Vent
DIR #2000534592 00
DIR #2000534593 00
Figure 3-1 Two-Pipe Sidewall Termination - See
page 22 for more details
Figure 3-2 PVC/CPVC Concentric Sidewall
Termination - See page 25 for more details
Direct venting options - Vertical Vent
DIR #2000534590 00
DIR #2000534588 00
DIR #2000534587 00
Figure 3-3 Two-Pipe Vertical Figure 3-4 PVC/CPVC Concentric Figure 3-5 Vertical Vent, Sidewall
Termination - See page 28 for more Vertical Termination - See page 30 Air
for more details
details
14
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FIRE TUBE COMBI
3
General venting
Installation & Service Manual
(continued)
Install vent and combustion air piping
The Noble Combi Boiler must be vented and
supplied with combustion and ventilation
air as described in this section. Ensure the
vent and air piping and the combustion
air supply comply with these instructions
regarding vent system, air system, and
combustion air quality. See also Section 1
of this manual.
Inspect finished vent and air piping
thoroughly to ensure all are airtight and
comply with the instructions provided and
with all requirements of applicable codes.
Failure to provide a properly installed vent
and air system will cause severe personal
injury or death.
This appliance requires a special venting
WARNING
system. Use only approved PVC, CPVC,
polypropylene or stainless steel pipe and
fittings listed in Tables 3C, 3D, and 3F for
vent pipe, and fittings. Failure to comply
could result in severe personal injury,
death, or substantial property damage.
DANGER
DO NOT mix components from different
WARNING systems. The vent system could fail,
causing leakage of flue products into the
living space. Mixing of venting materials
will void the warranty and certification of
the appliance.
NOTICE
Installation must comply with local
requirements and with the National
Fuel Gas Code, ANSI Z223.1 for U.S.
installations or CSA B149.1 for Canadian
installations.
The Noble Combi Boiler vent and air piping can be installed
through the roof or through a sidewall. Follow the procedures
in this manual for the method chosen. Refer to the information
in this manual to determine acceptable vent and air piping
length.
You may use any of the vent/air piping methods covered in
this manual. Do not attempt to install the Noble Combi Boiler
using any other means.
You must also install air piping from outside to the boiler
air intake adapter unless following the Optional Room Air
instructions on page 17 of this manual. The resultant
installation is direct vent (sealed combustion) .
Air intake/vent connections
1.
2.
Combustion Air Intake Connector (FIG. 3-6)
- Used to provide combustion air directly to the unit from
outdoors. A fitting is provided on the unit for final
connection. Combustion air piping must be supported
per guidelines listed in the National Mechanical Code,
Section 305, Table 305.4 or as local codes dictate.
Vent Connector (FIG.'s 3-6 thru 3-10) - Used to provide a
passageway for conveying combustion gases to the
outside. A transition fitting is provided on the unit for
final connection. Vent piping must be supported per the
National Building Code, Section 305, Table 305.4 or as
local codes dictate.
Figure 3-6 Near Boiler Air Piping
AIR
For closet and alcove installations, CPVC,
WARNING polypropylene or stainless steel material
MUST BE used in a closet/alcove structure.
Failure to follow this warning could result
in fire, personal injury, or death.
Improper installation of venting systems
CAUTION
may result in injury or death.
NOTICE
Follow the instructions in Section 1, page
11 of this manual when removing a boiler
from an existing vent system.
WARNING
Do not connect any other appliance to the
vent pipe or multiple boilers to a common
vent pipe. Failure to comply could result in
severe personal injury, death, or substantial
property damage.
DIR #2000528317 00
15
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FIRE TUBE COMBI
3
Installation & Service Manual
General venting
Sizing
The Noble Combi Boiler uses model specific combustion air
intake and vent piping sizes as detailed in Table 3A below.
NOTICE
Table 3A Air Intake/Vent Piping Sizes
Model
2" Max Vent/Air 3" Max Vent/Air
110
100 feet
100 feet
150
60 feet
100 feet
199
N/A
100 feet
NOTICE
Increasing or decreasing combustion air
or vent piping sizes is not authorized,
unless referenced in manual.
Minimum / Maximum allowable combustion
air and vent piping lengths are as follows:
Combustion Air = 7 equivalent feet minimum / 100 equivalent
feet maximum
Vent = 7 equivalent feet minimum / 100 equivalent feet
maximum
When determining equivalent combustion air and vent length,
add 5 feet for each 90° elbow and 3 feet for each 45° elbow.
EXAMPLE: 20 feet of PVC pipe + (4) 90° elbows + (2) 45°
elbows + (1) concentric vent kit (100140480) = 49 equivalent
feet of piping.
NOTICE
The appliance output rating will reduce by
up to 1.5% for each 25 feet of vent length.
Table 3B Concentric Vent Kit Equivalent Vent Lengths
Model
Kit
Equivalent Vent Vent
Number
Length
Size
110 - 150
110 - 199
100140485
100140480
3 feet
3 feet
2 inch
3 inch
Materials
Air inlet pipe materials:
The air inlet pipe(s) must be sealed. Choose acceptable
combustion air inlet pipe materials from the following list:
PVC, CPVC, Polypropylene or ABS
Galvanized steel vent pipe with joints and seams sealed as
specified in this section.
Type “B” double-wall vent with joints and seams sealed as
specified in this section.
AL29-4C, stainless steel material to be sealed to
specification of its manufacturer.
*Plastic pipe may require an adapter (not provided) to
transition between the air inlet connection on the appliance
and the plastic air inlet pipe.
16
WARNING Using air intake materials other than those
specified can result in personal injury,
death or property damage.
The use of double-wall vent or insulated
material for the combustion air inlet pipe is
recommended in cold climates to prevent
the condensation of airborne moisture in
the incoming combustion air.
Sealing of Type “B” double-wall vent material or galvanized
vent pipe material used for air inlet piping on a sidewall or
vertical rooftop Combustion Air Supply System:
a. Seal all joints and seams of the air inlet pipe using either
Aluminum Foil Duct Tape meeting UL Standard 723 or
181A-P or a high quality UL Listed silicone sealant such as
those manufactured by Dow Corning or General Electric.
b. Do not install seams of vent pipe on the bottom of
horizontal runs.
c. Secure all joints with a minimum of three (3) sheet metal
screws or pop rivets. Apply Aluminum Foil Duct Tape or
silicone sealant to all screws or rivets installed in the vent
pipe.
d. Ensure that the air inlet pipes are properly supported.
The PVC, CPVC, or ABS air inlet pipe should be cleaned and
sealed with the pipe manufacturer’s recommended solvents
and standard commercial pipe cement for the material used.
The PVC, CPVC, ABS, or Flex Duct air inlet pipe should
use a silicone sealant to ensure a proper seal at the appliance
connection and the air inlet cap connection. Dryer vent or
flex duct should use a screw type clamp to seal the vent to
the appliance air inlet and the air inlet cap. Proper sealing of
the air inlet pipe ensures that combustion air will be free of
contaminants and supplied in proper volume.
When a sidewall or vertical rooftop combustion air supply
system is disconnected for any reason, the air inlet pipe
must be resealed to ensure that combustion air will be free of
contaminants and supplied in proper volume.
DANGER
Failure to properly seal all joints and seams
as required in the air inlet piping may
result in flue gas recirculation, spillage
of flue products and carbon monoxide
emissions causing severe personal injury
or death.
™
FIRE TUBE COMBI
3
General venting
Installation & Service Manual
(continued)
Optional room air
NOTICE
Optional room air is intended for
commercial applications. Combustion air
piping to the outside is recommended for
residential applications.
Commercial applications utilizing the Noble Combi Boiler
may be installed with a single pipe carrying the flue products
to the outside while using combustion air from the equipment
room. In order to use the room air venting option the
following conditions and considerations must be followed.
•
•
•
•
•
The unit MUST be installed with the appropriate
room air kit (Table 3C).
The equipment room MUST be provided with
properly sized openings to assure adequate
combustion air. Please refer to instructions provided
with the room air kit.
There will be a noticeable increase in the noise level
during normal operation from the inlet air opening.
Using the room air kit makes the unit vulnerable to
combustion air contamination from within the
building.
Please review Section 1, Prevent
Combustion Air Contamination, to ensure proper
installation.
Vent system and terminations must comply with the
standard venting instructions set forth in this
manual.
Please read the information given in Table 1A, page 10,
listing contaminants and areas likely to contain them. If
contaminating chemicals will be present near the location of the
boiler combustion air inlet, have your installer pipe the boiler
combustion air and vent to another location, per this manual.
WARNING
If the boiler combustion air inlet is located
in a laundry room or pool facility, for
example, these areas will always contain
hazardous contaminants.
To prevent the potential of severe personal
WARNING injury or death, check for areas and products
listed in Table 1A, page 10 before installing
the boiler or air inlet piping.
If contaminants are found, you MUST:
• Remove contaminants permanently.
—OR—
• Relocate air inlet and vent
terminations to other areas.
When utilizing the single pipe method,
WARNING provisions for combustion and ventilation
air must be in accordance with Air for
Combustion and Ventilation, of the
latest edition of the National Fuel Gas
Code, ANSI Z223.1, in Canada, the latest
edition of CGA Standard B149 Installation
Code for Gas Burning Appliances and
Equipment, or applicable provisions of the
local building codes.
Table 3C Optional Room Air Kit
Model
110 - 150
110 - 199
Kit Number
100157614
100157615
Air Size
2"
3"
Air contamination
Pool and laundry products and common household and hobby
products often contain fluorine or chlorine compounds.
When these chemicals pass through the boiler, they can form
strong acids. The acid can eat through the boiler wall, causing
serious damage and presenting a possible threat of flue gas
spillage or boiler water leakage into the building.
17
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FIRE TUBE COMBI
3
Installation & Service Manual
General venting
PVC/CPVC:
1.
This product has been approved for use with the PVC/CPVC
vent materials listed in Table 3D.
Installing vent and air piping
WARNING Use only the vent materials, primer, and
cement specified in Table 3D to make the vent
connections. Failure to follow this warning
could result in fire, personal injury, or death.
2.
Work from the boiler to vent or air termination. Do
not exceed the lengths given in this manual for the air
or vent piping.
Cut pipe to the required lengths and deburr the inside
and outside of the pipe ends.
3.
Chamfer outside of each pipe end to ensure even
cement distribution when joining.
4.
Clean all pipe ends and fittings using a clean dry rag.
(Moisture will retard curing and dirt or grease will
prevent adhesion.)
NOTICE
Use only cleaners, primers, and solvents that
are approved for the materials which are joined
together.
5.
NOTICE
All PVC vent pipes must be glued, properly
supported, and the exhaust must be pitched
a minimum of a 1/4 inch per foot back to the
boiler (to allow drainage of condensate).
Dry fit vent or air piping to ensure proper fit up before
assembling any joint. The pipe should go a third to
two-thirds into the fitting to ensure proper sealing after
cement is applied.
6.
Priming and Cementing:
a. Handle fittings and pipes carefully to prevent
contamination of surfaces.
b. Apply a liberal even coat of primer to the fitting
socket and to the pipe end to approximately 1/2"
beyond the socket depth.
c. Apply a second primer coat to the fitting socket.
WARNING
Insulation should not be used on PVC or CPVC
venting materials. The use of insulation will
cause increased vent wall temperatures, which
could result in vent pipe failure.
WARNING
For installations using 2" vent, the first seven
(7) equivalent feet of vent must be CPVC (field
supplied). See examples below.
d.
WARNING
When transitioning from 2" to 3" vent diameter,
a 2" pipe section and 2" to 3" increaser are
required to be CPVC when PVC/CPVC vent
is used.
e.
f.
Examples: 1. Seven (7) feet vertical
2. Connector + 90° elbow + 2 feet horizontal
3. One (1) foot vertical + 90° elbow + 1 foot
horizontal
g.
While primer is still wet, apply an even coat of
approved cement to the pipe equal to the depth of
the fitting socket along with an even coat of
approved cement to the fitting socket.
Apply a second coat of cement to the pipe.
While the cement is still wet, insert the pipe into
the fitting, if possible twist the pipe a 1/4 turn as
you insert it. NOTE: If voids are present,
sufficient cement was not applied and joint could
be defective.
Wipe excess cement from the joint removing ring
or beads as it will needlessly soften the pipe.
Figure 3-7 Near Boiler PVC/CPVC Venting
Table 3D PVC/CPVC Vent Pipe and Fittings
Approved PVC/CPVC Vent Pipe and Fittings
Item
Vent pipe
Vent fittings
Material
Standard
PVC Schedule 40, 80
ANSI/ASTM D1785
PVC - DWV
ANSI/ASTM D2665
CPVC Schedule 40, 80
ANSI/ASTM F441
PVC Schedule 40
ANSI/ASTM D2466
PVC Schedule 80
ANSI/ASTM D2467
CPVC Schedule 80
ANSI/ASTM F439
PVC - DWV
ANSI/ASTM D2665
Pipe Cement / PVC
Primer
CPVC
VENT
AIR
ANSI/ASTM D2564
ANSI/ASTM F493
NOTICE: DO NOT USE CELLULAR (FOAM) CORE PIPE
NOTE: In Canada, CPVC and PVC vent pipe, fittings and cement/
primer must be ULC-S636 certified.
18
DIR #2000528318 00
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FIRE TUBE COMBI
3
General venting
Polypropylene:
(continued)
NOTICE
This product has been approved for use with polypropylene
vent with the manufacturers listed in Table 3E.
All terminations must comply with listed options in this
manual and be a single-wall vent offering.
For support and special connections required, see the
manufacturer's instructions. All vent is to conform to standard
diameter and equivalent length requirements established.
NOTICE
When determining equivalent combustion air and vent length
for polypropylene single-wall piping:
• 1 foot of Duravent 4 inch single-wall pipe is equivalent
to 1.6 feet of piping
Insulation should not be used on
polypropylene venting materials. The use
of insulation will cause increased vent wall
temperatures, which could result in vent
pipe failure.
Use only the adapters and vent system listed
WARNING
in Tables 3E and 3F. DO NOT mix vent
systems of different types or manufacturers,
unless listed in this manual. Failure to
comply could result in severe personal injury,
death, or substantial property damage.
For use of flex pipe, it is recommended to have the vent material
in 32°F or higher ambient space before bending at installation.
No bends should be made to greater than 45° and ONLY
installed in vertical or near vertical installations (FIG. 3-8).
Figure 3-8 Near Boiler Flexible Polypropylene Venting
Duravent 3”
CAP
B
Duravent 4”
“B” DIM
“A” DIM
3” RIGID 3” FLEX 4” FLEX
10 FT 60 FT 90 FT
20 FT 53 FT 80 FT
30 FT 47 FT 70 FT
40 FT 40 FT 60 FT
50 FT 33 FT 50 FT
60 FT 27 FT 40 FT
70 FT 20 FT 30 FT
80 FT 13 FT 20 FT
7 FT 10 FT
90 FT
A
“B” DIM
“A” DIM
4” RIGID 4” FLEX 5” FLEX
10 FT 30 FT 90 FT
20 FT 27 FT 80 FT
30 FT 23 FT 70 FT
40 FT 20 FT 60 FT
50 FT 17 FT 50 FT
60 FT 13 FT 40 FT
70 FT 10 FT 30 FT
80 FT
7 FT 20 FT
90 FT
3 FT 10 FT
Centrotherm 3”
Centrotherm 4”
“A” DIM
“B” DIM
3” RIGID 3” FLEX 4” FLEX
10 FT 45 FT 90 FT
20 FT 40 FT 80 FT
30 FT 35 FT 70 FT
40 FT 30 FT 60 FT
50 FT 25 FT 50 FT
60 FT 20 FT 40 FT
70 FT 15 FT 30 FT
80 FT 10 FT 20 FT
5 FT 10 FT
90 FT
“A” DIM “B” DIM
4” RIGID 4” FLEX
10 FT 33 FT
20 FT 29 FT
30 FT 26 FT
40 FT 22 FT
50 FT 18 FT
60 FT 15 FT
70 FT 11 FT
7 FT
80 FT
4 FT
90 FT
The installer must use a specific vent
starter adapter at the flue collar connection,
supplied by the vent manufacturer to
adapt to its vent system. See Table 3F for
approved vent adapters. Discard CPVC
starter piece.
All vent connections MUST be secured by
the vent manufacturer's joint connector
(FIG. 3-9).
WARNING
Flexible polypropylene
CHIMNEY
Installation & Service Manual
NOTICE
Installations must comply with applicable
national, state, and local codes. For
Canadian installation, polypropylene vent
must be listed as a ULC-S636 approved
system.
NOTICE
Installation of a polypropylene vent system
should adhere to the vent manufacturer’s
installation instructions supplied with the
vent system.
Figure 3-9 Near Boiler Polypropylene Venting Model 199
JOINT CONNECTOR REQUIRED
AT ALL COMPONENT CONNECTIONS
OF VENT SYSTEM
*NOTES: 1) FLEX PIPE MAY ONLY BE RUN IN A VERTICAL ORIENTATION
2) ALL VENT LENGTHS REPRESENTED IN ABOVE CHARTS ARE
EQUIVALENT LENGTHS.
3) SECTION A IS EQUIVALENT FEET OF RIGID PIPE, WHICH MAY
INCLUDE 45 AND 90° ELBOWS. PLEASE SEE SIZING SECTION
FOR DETERMINING EQUIVALENT FEET.
IMG00840
Table 3E Polypropylene Vent Pipe and Fittings
Approved Polypropylene Vent Manufacturers
Make
Model
Centrotherm Eco Systems
InnoFlue SW/Flex
Duravent (M & G Group)
PolyPro Single-Wall / PolyPro Flex
DIR #2000528329 00
Table 3F Approved Polypropylene Terminations and Adapters
Duravent Polypro
Centrotherm InnoFlue SW
Model Polypropylene Adapter/
Flue Clamp
110 - 199
ISAG0303 w/IAFC03
Joint
Sidewall Retaining
Polypropylene
Joint
Sidewall Adapter*
Sidewall Kit
Connector
Bracket*
Adapter
Connector
IANS03
IATP0303
ISTAGL0303
3PPS-AD
3PPS-LB
3PPS-HLK
* These parts are only needed if the alternate sidewall termination assembly is used.
19
Installation & Service Manual
™
FIRE TUBE COMBI
3
General venting
Stainless steel vent:
Installation of a stainless steel vent system
should adhere to the stainless steel vent
manufacturer’s installation instructions
supplied with the vent system.
NOTICE
This product has been approved for use with stainless steel
using the manufacturers listed in Table 3G.
WARNING
NOTICE
NOTICE
Use only the materials, vent systems, and
terminations listed in Tables 3G and 3H.
DO NOT mix vent systems of different
types or manufacturers. Failure to comply
could result in severe personal injury,
death, or substantial property damage.
Figure 3-10 Near Boiler Stainless Steel Venting
VENT
The installer must use a specific vent
starter adapter at the flue collar connection,
supplied by the vent manufacturer to
adapt to its vent system. See Table 3H for
approved vent adapters. Discard CPVC
starter piece.
UNIVERSAL ADAPTER
(FACTORY SUPPLIED)
Installations must comply with applicable
national, state, and local codes. Stainless
steel vent systems must be listed as a
UL-1738 approved system for the United
States and a ULC-S636 approved system
for Canada.
DIR #2000528338 00
Table 3G Stainless Steel Vent Pipe and Fittings
Approved Stainless Steel Vent Manufacturers
Make
Model
Dura Vent (M & G Group)
FasNSeal Vent / FasNSeal Flex* Vent
Z-Flex (Nova Flex Group)
Z-Vent
Heat Fab (Selkirk Corporation)
Saf-T Vent
*Use of FasNSeal Flex smooth inner wall vent is to be used in vertical or near vertical sections only, taking precaution to ensure
no sagging occurs of the vent system. Connect to the FasNSeal rigid vent using specially designed adapters and sealing method,
see manufacturer’s instructions.
Table 3H Approved Stainless Steel Terminations and Adapters
Model
110 - 199
ProTech
Heat Fab
Z Flex
FasNSeal
Saf-T Vent
Z-Vent
**Boiler
Flue
Adapter Termination
300715
FSBS3
(Intake Air) FSRC3(R.C)
Intake
Intake
*Boiler
Flue
**Boiler
Air
Air
Adapter Termination
Adapter
Termination
Termination
303889
--
9392
5300CI
9314TERM
*The stainless steel venting option is only available in 3" vent diameters.
20
--
Flue
Intake Air
Termination Termination
2SVSTP03
2SVSTEX0390
2SVSRCX03
™
FIRE TUBE COMBI
4
Installation & Service Manual
Sidewall direct venting
Vent/air termination – sidewall
Follow instructions below when
WARNING
determining vent location to avoid
possibility of severe personal injury, death,
or substantial property damage.
WARNING
A gas vent extending through an exterior
wall shall not terminate adjacent to a wall
or below building extensions such as eaves,
parapets, balconies, or decks. Failure to
comply could result in severe personal
injury, death, or substantial property
damage.
If using the sidewall termination:
3. The air piping must terminate in a down-turned elbow
as shown in FIG. 4-1A. This arrangement avoids
recirculation of flue products into the combustion air
stream.
4. The vent piping must terminate in an elbow pointed
outward or away from the air inlet, as shown in FIG. 4-1A.
WARNING
Determine location
Locate the vent/air terminations using the following
guidelines:
1. The total length of piping for vent or air must not exceed
the limits given in the General Venting Section on page
16 of this manual.
2. You must consider the surroundings when terminating
the vent and air:
a. Position the vent termination where vapors will
not damage nearby shrubs, plants or air
conditioning equipment or be objectionable.
b. The flue products will form a noticeable plume as
they condense in cold air. Avoid areas where the
plume could obstruct window views.
c. Prevailing winds could cause freezing of
condensate and water/ice buildup where flue
products impinge on building surfaces or plants.
d. Avoid possibility of accidental contact of flue
products with people or pets.
e. Do not locate the terminations where wind eddies
could affect performance or cause recirculation,
such as inside building corners, near adjacent
buildings or surfaces, window wells, stairwells,
alcoves, courtyards, or other recessed areas.
Figure 4-1A PVC/CPVC/Polypropylene Sidewall
Termination of Air and Vent w/Field Supplied Fittings
TO BOILER
INTAKE AIR
CONNECTION
Do not exceed the maximum lengths of
the outside vent piping shown in FIG.
4-1A. Excessive length exposed to the
outside could cause freezing of condensate
in the vent pipe, resulting in potential boiler
shutdown.
When venting out a sidewall using PVC, CPVC, or
Polypropylene vent materials, an optional sidewall vent
termination kit can be ordered (reference Table 4A for kit
numbers).
Table 4A Alternate Sidewall Vent Kit
Model
Kit
Air Vent Centerline
Number Size Size
Width
110 - 150
100157609
2"
2"
5 5/8"
110 - 199
100157610
3"
3"
5 5/8"
Figure 4-1B Alternate PVC/CPVC/ Polypropylene
Sidewall Termination of Air and Vent
TO BOILER
INTAKE AIR
CONNECTION
FROM BOILER
VENT PIPE
CONNECTION
12"
MIN
TO
OVERHANG
POSSIBLE ORIENTATIONS
VENT / AIR
TERMINATION
BIRD SCREEN
12"
MIN
FROM BOILER
VENT PIPE
CONNECTION
12” MIN
15” MAX
GRADE OR
SNOW LINE
TERMINATION
PLATE
12”
MIN
BIRD SCREEN
GRADE OR
SNOW LINE
21
™
FIRE TUBE COMBI
4
Installation & Service Manual
Sidewall direct venting
Vent/air termination – sidewall
Figure 4-2A Clearance to Gravity Air Inlets w/Field
Supplied Fittings
Figure 4-1C Alternate Venting Arrangement (if Space
Allows) w/Field Supplied Fittings
TO BOILER
INTAKE AIR
CONNECTION
COUPLING
12”
MIN
12” MIN
15” MAX
FROM BOILER
VENT PIPE
CONNECTION
BIRD
SCREEN
(TYPICAL)
BIRD SCREEN
12”
MIN
12”
MIN
BIRD
SCREEN
GRADE OR
SNOW LINE
ALTERNATE VENTING ARRANGEMENT
(IF SPACE PERMITS)
12”
MIN
Figure 4-2B Clearance to Gravity Air Inlets using an
Optional Vent Kit
Figure 4-1D Alternate Venting Arrangement - Typical
Stainless Steel Sidewall Termination of Air and Vent w/
Field Supplied Fittings
TO BOILER
INTAKE AIR
CONNECTION
12"
MIN.
12" MIN
15" MAX
VENT / AIR
TERMINATION
12"
MIN.
FROM
BOILER
VENT PIPE
CONNECTION
12"
MIN.
Figure 4-3A Clearance to Forced Air Inlets using an
Optional Vent Kit
IF LESS
THAN 10’
12" MIN
BIRD SCREEN
GRADE OR SNOW LINE
5.
Maintain clearances as shown in FIG.’s 4-1A thru 4-3B,
pages 21 and 22. Also maintain the following:
a. Vent must terminate:
• At least 6 feet from adjacent walls.
• No closer than 12 inches below roof overhang.
• At least 7 feet above any public walkway.
• At least 3 feet above any forced air intake within
10 feet.
• No closer than 12 inches below or horizontally
from any door or window or any other gravity air
inlet.
b. Air inlet must terminate at least 12 inches above
grade or snow line; at least 12 inches below the vent
termination (FIG. 4-1B); and the vent pipe must not
extend more than 24 inches vertically outside the
building.
c. Do not terminate closer than 4 feet horizontally
from any electric meter, gas meter, regulator, relief
valve, or other equipment. Never terminate above or
below any of these within 4 feet horizontally.
6. Locate terminations so they are not likely to be damaged by
foreign objects, such as stones or balls, or subject to buildup
of leaves or sediment.
22
VENT / AIR
TERMINATION
36"
MIN.
FORCED AIR
INLET
7' MIN. ABOVE ANY
PUBLIC WALKWAY
Figure 4-3B Clearance to Forced Air Inlets w/Field
Supplied Fittings
IF LESS
THAN 10’
36”
MIN
FORCED AIR
INLET
7’ MIN ABOVE ANY
PUBLIC WALKWAY
BIRD
SCREEN
(TYPICAL)
™
FIRE TUBE COMBI
4
Sidewall direct venting
(continued)
Prepare wall penetrations
1.
2.
3.
4.
5.
Installation & Service Manual
Air pipe penetration:
a. Cut a hole for the air pipe. Size the air pipe hole as
close as desired to the air pipe outside diameter.
Vent pipe penetration:
a. Cut a hole for the vent pipe. For either combustible
or noncombustible construction, size the vent pipe
hole with at least a 1/2 inch clearance around the vent
pipe outer diameter:
• 3½ inch hole for 2 inch vent pipe
• 4½ inch hole for 3 inch vent pipe
b. Insert a galvanized metal thimble in the vent pipe
hole as shown in FIG. 4-4A.
Use the sidewall termination plate as a template for
correct location of hole centers.
Follow all local codes for isolation of vent pipe when
passing through floors or walls.
Seal exterior openings thoroughly with exterior caulk.
Figure 4-4A Sidewall Termination Assembly w/Field
Supplied Fittings
Figure 4-5A Multiple Vent Terminations w/Field Supplied
Fittings (must also comply with Figure 4-1A)
Figure 4-5B Alternate Multiple Vent Terminations (must
also comply with Figure 4-1B)
12" MIN. BETWEEN EDGE OF AIR
INLET AND ADJACENT VENT OUTLET
ELBOW
VENT
AIR PIPING
VENT PIPING
AIR
BIRD SCREEN
GALVANIZED
THIMBLE
ELBOW
SIDEWALL
TERMINATION PLATE
BIRD SCREEN
Multiple vent/air terminations
VENT / AIR
TERMINATION
1. When terminating multiple boilers terminate each vent/
air connection as described in this manual (FIG. 4-5A).
WARNING All vent pipes and air inlets must terminate
at the same height to avoid possibility
of severe personal injury, death, or
substantial property damage.
2. Place wall penetrations to obtain minimum clearance
of 12 inches between edge of air inlet and adjacent vent
outlet, as shown in FIG. 4-5A for U.S. installations. For
Canadian installations, provide clearances required by
CSA B149.1 Installation Code.
3. The air inlet of a Noble Combi Boiler is part of a direct
vent connection. It is not classified as a forced air intake
with regard to spacing from adjacent boiler vents.
23
™
FIRE TUBE COMBI
4
Installation & Service Manual
Sidewall direct venting
Sidewall termination – optional concentric vent
Description and usage
The manufacturer offers optional concentric combustion air
and vent pipe termination kits (Factory Kit #100140480 - 3"
or #100140485 - 2"). Both combustion air and vent pipes
must attach to the termination kit. The termination kit must
terminate outside the structure and must be installed as shown
below in FIG. 4-6.
The required combustion vent pipe and fittings are listed in
Table 3B, on page 16 of this manual.
Figure 4-6 Concentric Sidewall Termination
3. Cut one (1) hole (5 inch diameter for #100140480
installations or 4 inch diameter for #100140485 installations)
into the structure to install the termination kit.
4. Partially assemble the concentric vent termination kit.
Clean and cement using the procedures found in these
instructions.
a. Cement the Y concentric fitting to the larger kit pipe
(FIG. 4-7).
b. Cement the rain cap to the smaller diameter kit pipe
(FIG. 4-7).
Figure 4-7 Kit Contents
Sidewall termination installation
1. Determine the best location for the termination kit (see
FIG. 4-6).
2. Reference the Determine Location Section on page 21 of
this manual for general termination considerations.
24
™
FIRE TUBE COMBI
4
Sidewall direct venting
Installation & Service Manual
(continued)
Sidewall termination – optional concentric vent models
Figure 4-8 Concentric Vent Dimensional Drawing
NOTICE
Instead of cementing the smaller pipe to
the rain cap, a field-supplied stainless steel
screw may be used to secure the two (2)
components together when field disassembly
is desired for cleaning (see FIG. 4-9).
When using the alternate screw assembly
WARNING method, drill a clearance hole in the rain
cap and a pilot hole in the vent pipe for
the screw size being used. Failure to drill
adequate holes may cause cracking of PVC
components, allowing combustion products
to be recirculated. Failure to follow this
warning could result in personal injury or
death.
WARNING
Do not operate the appliance with the rain
cap removed or recirculation of combustion
products may occur. Water may also collect
inside the larger combustion air pipe and
flow to the burner enclosure. Failure to
follow this warning could result in product
damage or improper operation, personal
injury, or death.
5. Install the Y concentric fitting and pipe assembly through
the structure’s hole.
NOTICE
Do not allow insulation or other materials
to accumulate inside the pipe assembly
when installing through the hole.
6. Install the rain cap and small diameter pipe assembly into
the Y concentric fitting and large pipe assembly. Ensure
small diameter pipe is bottomed and cemented in the Y
concentric fitting.
7. Secure the assembly to the structure as shown in FIG.
4-10 using field-supplied metal strapping or equivalent
support material.
Ensure termination location clearance
NOTICE
dimensions are as shown in FIG. 4-6.
NOTICE
If assembly needs to be extended to
allow sidewall thickness requirement, the
two (2) pipes supplied in the kit may
be replaced by using the same diameter,
field-supplied SDR-26 PVC (D2241) pipe.
Do not extend dimension D more than 60
inches (see FIG. 4-8).
NOTICE
If assembly needs to be reduced, dimension
D can be as short as possible.
Figure 4-9 Rain Cap to Vent Pipe Alternate Assembly
25
™
FIRE TUBE COMBI
4
Installation & Service Manual
Sidewall direct venting
Sidewall termination – optional concentric vent
Figure 4-10 Concentric Vent Sidewall Attachment
CAUTION
DO NOT use field-supplied couplings to
extend pipes. Airflow restriction will occur
and may cause intermittent operation.
8. Cement appliance combustion air and vent pipes to the
concentric vent termination assembly. See FIG. 4-10 for
proper pipe attachment.
9. Operate the appliance one (1) heat cycle to ensure
combustion air and vent pipes are properly connected to
the concentric vent termination connections.
Multiventing sidewall terminations
When two (2) or more direct vent appliances are vented near
each other, each appliance must be individually vented (see FIG.
4-11). NEVER common vent or breach vent this appliance.
When two (2) or more direct vent appliances are vented near
each other, two (2) vent terminations may be installed as shown
in FIG. 4-11. It is important that vent terminations be made as
shown to avoid recirculation of flue gases.
12"
MINIMUM
VENT
COMBUSTION
AIR
Figure 4-11 Concentric Vent and Combustion Air Termination
26
™
FIRE TUBE COMBI
5
Installation & Service Manual
Vertical direct venting
Vent/air termination – vertical
WARNING
Follow instructions below when
determining vent location to avoid
possibility of severe personal injury, death
or substantial property damage.
Determine location
Locate the vent/air terminations using the following
guidelines:
1. The total length of piping for vent or air must not exceed
the limits given in the General Venting Section on page
16 of this manual.
Figure 5-1A PVC/CPVC/Polypropylene
Termination of Air and Vent
ALTERNATE INTAKE LOCATIONS:
INTAKE PIPES MAY BE LOCATED
ANYWHERE WITHIN 24” OF VENT
PIPE
BIRD SCREEN
(TYPICAL)
VENT
COUPLING
(FIELD SUPPLIED)
6” MINIMUM
ABOVE ROOF /
SNOW LINE
2. Prepare the vent termination and the air termination
elbow (FIG. 5-1A) by inserting bird screens.
3. The vent must terminate at least 3 feet above the highest
place in which the vent penetrates the roof and at least
2 feet above any part of a building within 10 horizontal
feet.
4. The air piping must terminate in a down-turned 180°
return pipe no further than 2 feet from the center of the
vent pipe. This placement avoids recirculation of flue
products into the combustion air stream.
5. The vent piping must terminate in an up-turned coupling
as shown in FIG. 5-1A. The top of the coupling must
be at least 1 foot above the air intake. When the vent
termination uses a rain cap as illustrated in FIG. 5-1B
maintain at least 36" (914 mm) above the air inlet. The
air inlet pipe and vent pipe can be located in any desired
position on the roof, but must always be no further than
2 feet (.6 m) apart and with the vent termination at least
1 foot for PVC and 3 feet for stainless steel, above the air
intake.
6. Maintain the required dimensions of the finished
termination piping as shown in FIG. 5-1A.
7. Do not extend exposed vent pipe outside of building
more than shown in this document. Condensate could
freeze and block vent pipe.
WARNING
Vertical
VENT OUTLET
12” MINIMUM
ABOVE AIR INLET
COMBUSTION
AIR
Figure 5-1B Stainless Steel Vertical Termination of Air
and Vent
ALTERNATE INTAKE LOCATIONS:
INTAKE PIPES MAY BE LOCATED
ANYWHERE WITHIN 24” (610 MM)
OF VENT PIPE
BIRD SCREEN
(TYPICAL)
VENT
6" (152 MM) MINIMUM
ABOVE ROOF /
SNOW LINE
COMBUSTION
AIR
VENT OUTLET
36” (914 MM) MINIMUM
ABOVE AIR INLET
8. Locate terminations so they are not likely to be damaged by
foreign objects, such as stones or balls, or subject to buildup
of leaves or sediment.
Rooftop vent and air inlet terminations
must terminate in the same pressure
zone, unless vertical vent sidewall air is
set up, reference this section, page 28 and
Section 4 - Air Intake Clearances.
27
™
FIRE TUBE COMBI
5
Installation & Service Manual
Vertical direct venting
Vent/air termination – vertical
Prepare roof penetrations
1.
Air pipe penetration:
a. Cut a hole for the air pipe. Size the air pipe hole as
close as desired to the air pipe outside diameter.
2.
Vent pipe penetration:
a. Cut a hole for the vent pipe. For either combustible
or noncombustible construction, size the vent pipe
hole with at least a 1/2 inch clearance around the
vent pipe outer diameter:
• 4½ inch hole for 3 inch vent pipe
• 5½ inch hole for 4 inch vent pipe
b. Insert a galvanized metal thimble in the vent pipe
hole.
3. Space the air and vent holes to provide the minimum
spacing shown in FIG. 5-1A, page 27.
4. Follow all local codes for isolation of vent pipe when
passing through floors, ceilings, and roofs.
5. Provide flashing and sealing boots sized for the vent pipe
and air pipe.
Multiple vent/air terminations
1. When terminating multiple boilers, terminate each vent/
air connection as described in this manual (FIG. 5-2).
WARNING
Terminate all vent pipes at the same height
and all air pipes at the same height to
avoid possibility of severe personal injury,
death, or substantial property damage.
2. Place roof penetrations to obtain minimum clearance of
12 inches between edge of air intake elbow and adjacent
vent pipe of another boiler for U.S. installations (see
FIG. 5-2). For Canadian installations, provide clearances
required by CSA B149.1 Installation Code.
3. The air inlet of a Noble Combi Boiler is part of a direct
vent connection. It is not classified as a forced air intake
with regard to spacing from adjacent boiler vents.
28
Figure 5-2 Vertical Terminations with Multiple Boilers
Figure 5-3 Alternate Vertical Terminations with Multiple
Boilers
™
FIRE TUBE COMBI
5
Vertical direct venting
Installation & Service Manual
(continued)
Vertical termination – optional concentric vent
Description and usage
The manufacturer offers an optional concentric combustion
air and vent pipe termination kit. Both combustion air
and vent pipes must attach to the termination kit. The
termination kit must terminate outside the structure and
must be installed as shown in FIG. 5-4.
Field supplied pipe and fittings are required to complete
the installation.
The required combustion air and vent pipe fittings are
listed in Table 3B, on page 16 of this manual.
Vertical termination installation
2. Cut one (1) hole (5 inch diameter for #100140480 installations
or 4 inch diameter for #100140485 installations) into the
structure to install the termination kit.
3. Partially assemble the concentric vent termination kit.
Clean and cement following the cleaning procedures in
these instructions.
a. Cement the Y concentric fitting to the larger
diameter kit pipe (see FIG. 4-7, page 24).
b. Cement rain cap to the smaller diameter kit pipe (see
FIG. 4-7, page 24).
Instead of cementing the smaller pipe to
the rain cap, a field supplied stainless steel
screw may be used to secure the two (2)
components together when field disassembly
is desired for cleaning (see FIG. 4-9, page
25).
When
using the alternate screw assembly
WARNING
method, drill a clearance hole in the rain
cap and a pilot hole in the vent pipe for
the screw size being used. Failure to drill
adequate holes may cause cracking of PVC
components, allowing combustion products
to be recirculated. Failure to follow this
warning could result in personal injury or
death.
NOTICE
1. See Section 5, Vertical Direct Venting - Determine
Location (where applicable).
Figure 5-4 Concentric Vertical Termination
Figure 5-5 Do Not Install U-Bend to Rain Cap
29
Installation & Service Manual
™
FIRE TUBE COMBI
5
Vertical direct venting
Vertical termination – optional concentric vent
WARNING
Do not operate the appliance with
the rain cap removed or recirculation
of combustion products may occur.
Water may also collect inside the larger
combustion air pipe and flow to the
burner enclosure. Failure to follow this
warning could result in product damage
or improper operation, personal injury,
or death.
CAUTION
6.
Install the rain cap and the small diameter pipe assembly
into the roof penetration assembly. Ensure the small
diameter pipe is cemented and bottomed in the Y concentric
fitting.
7.
Cement the appliance combustion air and vent pipes to
the concentric vent termination assembly. See FIG. 5-6 for
proper pipe attachment.
8.
Operate the appliance through one (1) heat cycle to ensure
combustion air and vent pipes are properly connected to
the concentric vent termination connections.
4. Install the Y concentric fitting pipe assembly through the
structure’s hole and field supplied roof boot/flashing.
NOTICE
Do not allow insulation or other materials
to accumulate inside the pipe assembly
when installing through the hole.
5. Secure the assembly to the roof structure as shown
below in FIG. 5-6 using field supplied metal strapping or
equivalent support material.
Figure 5-6 Concentric Vent Roof Installation
DO NOT use field-supplied couplings to
extend pipes. Airflow restriction will occur.
Multiventing vertical terminations
When two (2) or more direct vent appliances are vented near
each other, each appliance must be individually vented (see
FIG. 5-7). NEVER common vent or breach vent this appliance.
When two (2) or more direct vent appliances are vented near
each other, two (2) vent terminations may be installed as shown
in FIG. 5-7. It is important that vent terminations be made as
shown to avoid recirculation of flue gases.
Figure 5-7 Concentric Vent and Combustion Air Vertical
Termination
12”
MINIMUM
COMBUSTION
AIR (TYPICAL)
NOTICE
NOTICE
30
Ensure termination height is above the
roof surface or anticipated snow level (12
inches in U.S.A. or 18 inches in Canada) as
shown in FIG. 5-4, page 29.
If assembly is too short to meet height
requirement, the two (2) pipes supplied
in the kit may be replaced by using the
same diameter, field supplied SDR-26 PVC
(D2241) pipe. Do not extend dimension
D more than 60 inches (see FIG. 4-8, page
25).
12” (18” FOR CANADA)
MINIMUM CLEARANCE
ABOVE HIGHEST
ANTICIPATED SNOW
LEVEL. MAXIMUM OF
24” ABOVE ROOF.
™
FIRE TUBE COMBI
5
Vertical direct venting
Installation & Service Manual
(continued)
Alternate vertical concentric venting
This appliance may be installed with a concentric vent
arrangement where the vent pipe is routed through an
existing unused venting system; or by using the existing
unused venting system as a chase for vent and combustion
air routing.
Figure 5-8 Concentric Vent Example 1
FLUE EXHAUST
Concentric Venting Arrangement
SEAL
The venting is to be vertical through the roof. The annular
space between the O.D. of the vent pipe and the I.D. of the
existing unused venting system is utilized for the combustion
air source.
The minimum size of the existing vent system required to
achieve enough annular space for combustion air can be
found in Table 5A below.
The upper and lower termination as well as any other unsealed
joints in the existing vent system must be sealed to ensure that
all combustion air is drawn from under the vent cap as shown
in FIG.’s 5-8 and 5-9.
AIR INLET
12”
MIN
COMBUSTION AIR
EXISTING
SEAL
SEALED
CAP
DIR #2000534607 00
Approved venting materials must be used as specified in
Table 3D on page 18.
Follow all vent / air termination and clearance requirements
per this section to the appropriate example. Installation must
comply with local requirements and with the National Fuel
Gas Code.
*For concept illustration only. Individual installations may vary
due to job site specific equipment.
Figure 5-9 Concentric Vent Example 2
FLUE EXHAUST
The maximum allowable equivalent vent and air intake
lengths for this venting arrangement are to be determined
from the General Venting Section.
SEAL
COMBUSTION AIR
If an existing unused venting system is converted for use
with this method of concentric venting, the installer must
ensure that the existing venting system is clean and free from
particulate contamination that will harm this appliance and
cause increased nuisance calls or maintenance. See Table 1A
on page 10 for a list of corrosive contaminants and sources.
Two example scenarios of a concentric venting arrangement
are shown for illustrative purposes in FIG.’s 5-8 and 5-9.
AIR INLET
WITH SCREEN
EXISTING
SEAL
SEALED
CAP
Table 5A Alternate Vertical Concentric Vent / Chase Sizes
Model
Vent / Air
Inlet Size
Minimum Existing
Vent / Chase Size
110 - 150
2"
4"
110 - 199
3"
5"
DIR #2000534609 00
*For concept illustration only. Individual installations may vary
due to job site specific equipment.
31
™
FIRE TUBE COMBI
5
Vertical direct venting
Existing vent as a chase
Follow all existing termination and clearance requirements
and allowable pipe lengths. Use only approved venting
materials listed in the General Venting Section of this manual.
Figure 5-10 Existing Vent as a Chase
FLUE EXHAUST
AIR INLET
WITH SCREEN
SEAL
EXISTING
SEAL
SEALED
CAP
DIR #2000534613 00
*For concept illustration only. Individual installations
may vary due to job site specific equipment.
32
Installation & Service Manual
™
FIRE TUBE COMBI
6A
Installation & Service Manual
Hydronic piping
System water piping methods
The Noble Combi Boiler is designed to function in a closed
loop pressurized system not less than 12 psi (Non-metallic
system piping must have an oxygen barrier to be considered
a closed loop). A temperature and pressure gauge is included
to monitor system pressure and outlet temperature and
should be located on the boiler outlet.
General piping information
IMPORTANT All boiler piping must contain an oxygen
barrier. This will help prevent any excess
oxygen from entering the system.
Basic steps are listed below along with illustrations on the
following pages (FIG.’s 6-2 through 6-5), which will guide you
through the installation of the Noble Combi Boiler.
Each boiler installation must have an air elimination device,
which will remove air from the system. Install the boiler
so the gas ignition system components are protected from
water (dripping, spraying, etc.) during appliance operation
for basic service of circulator replacement, valves, and others.
1.
Connect the system return marked “Boiler Inlet”.
2.
Connect the system supply marked “Boiler Outlet”.
3.
Install purge and balance valve or shutoff valve and drain
on system return to purge air out of each zone.
Observe a minimum of a 1/4 inch clearance around all
un-insulated hot water pipes when openings around the
pipes are not protected by non-combustible materials.
4.
Install a backflow preventer on the cold feed make-up
water line.
5.
Install a pressure reducing valve on the cold feed makeup water line, (15 psi nominal). Check temperature and
pressure gauge (shipped separately), which should read a
minimum pressure of 12 psi.
6.
Install a system pump if necessary as shown on the piping
diagrams in this section. Make sure the circulator is
properly sized for the system and friction loss.
7.
Install an expansion tank on the system supply. Consult the
tank manufacturer’s instruction for specific information
relating to tank installation. Size the expansion tank for the
required system volume and capacity.
8.
Install an air elimination device on the system supply.
9.
Install a drain valve at the lowest point of the system.
Note: The boiler cannot be drained completely of water
without purging the unit with an air pressure of 15 psi.
Low water cutoff device
On a boiler installed above radiation level, some states and
local codes require a low water cutoff device at the time of
installation.
Chilled water system
If the boiler supplies hot water to heating coils in air handler
units, flow control valves or other devices must be installed to
prevent gravity circulation of heater water in the coils during
the cooling cycle. A chilled water medium must be piped in
parallel with the heater.
Freeze protection
Freeze protection for new or existing systems must use
glycol that is specially formulated for this purpose. This
includes inhibitors, which prevent the glycol from attacking
the metallic system components. Make certain to check that
the system fluid is correct for the glycol concentration and
inhibitor level. The system should be tested at least once
a year and as recommended by the producer of the glycol
solution. Allowance should be made for the expansion of the
glycol solution in the system piping.
Use only inhibited propylene glycol
WARNING
solutions, which are specifically formulated
for hydronic systems. Ethylene glycol is
toxic and can attack gaskets and seals used
in hydronic systems.
Heating fluid and Domestic Hot Water
(DHW) piping
The diameter of the heating fluid (hot boiler water) and DHW
piping will depend on the model number and size of the water
heater being installed.
10. This appliance is supplied with a relief valve sized in
accordance with ASME Boiler and Pressure Vessel Code,
Section IV (“Heating Boilers”). Pipe the discharge of the
safety relief valve to prevent injury in the event of pressure
relief. Pipe the discharge to a drain. Provide piping that is
the same size as the safety relief valve outlet. Never block
the outlet of the safety relief valve.
11. Install a field supplied strainer to prevent damage to the
heat exchanger caused by debris entering from the system
piping. When installing in a pre-existing system, a strainer/
filter capable of removing debris left in the system is
recommended.
See the *piping illustrations included in this section, FIG.’s 6-2
through 6-5 for suggested guidelines in piping the Noble Combi
Boiler with either zone valves or circulator pumps.
NOTICE
*Please note that these illustrations are
meant to show system piping concept only,
the installer is responsible for all equipment
and detailing required by local codes.
33
™
FIRE TUBE COMBI
6A
Hydronic piping
Near boiler piping components
1. Boiler system piping:
Boiler system piping MUST be sized per the pipe
requirements listed in Table 6A. Reducing the pipe size
can restrict the flow rate through the boiler, causing
inadvertent high limit shutdowns and poor system
performance.
2. Boiler circulating pump:
Factory supplied. System piping must be sized to meet the
minimum requirements in Table 6A on page 35.
3. Boiler isolation valves:
Field supplied. Full port ball valves are required. Failure
to use full port ball valves could result in a restricted flow
rate through the boiler.
4. Check valves:
Field supplied. Check valves are recommended for
installation as shown in FIG.’s 6-2 through 6-5. Failure
to install check valves could result in a reverse flow
condition during pump(s) off cycle.
5. Unions:
Field supplied. Recommended for unit serviceability.
6. Temperature and pressure gauge:
Factory supplied. The temperature and pressure gauge is
shipped loose. It is the responsibility of the contractor to
install the temperature and pressure gauge on the boiler
water outlet.
7. Pressure relief valve:
Factory supplied. The pressure relief valve is sized to
ASME specifications. Install the 3/4" NPT fitting on the
top right side of the boiler (images in this manual show
relief valve installed).
8. Boiler purge valve:
Field supplied. The boiler purge valve is used to
remove entrapped air from the heat exchanger during
start-up.
9. System temperature sensor (optional):
Factory supplied with the unit. The manufacturer offers
a system temperature sensor (100157718). The sensor is to
be installed in the heating loop downstream from the
boiler hot water piping and heating loop junction.
Typically the sensor will be located far enough downstream
to sense system diluted water temperature.
34
Installation & Service Manual
WARNING The National Standard Plumbing
Code, the National Plumbing Code of
Canada and the Uniform Plumbing
Code limit the pressure of the heat
transfer fluid to less than the minimum
working pressure of the potable water
system up to 30 psi maximum. Also,
the heat transfer fluid must be water
or other non-toxic fluid having a
toxicity of Class 1, as listed in Clinical
Toxicology of Commercial Products,
5th Edition.
10. Water Meter:
Field supplied. A water meter to monitor makeup
water is recommended. Makeup water volume should
not exceed 5% of total system per year.
11. Y-Strainer:
Field supplied. Install a Y-strainer or equivalent
multi-purpose strainer just before the boiler pump
at the inlet of the heat exchanger. This item is used to
remove system debris from older hydronic systems
and to protect newer systems.
™
FIRE TUBE COMBI
6A
Hydronic piping
Installation & Service Manual
(continued)
Figure 6-1 Pressure Drop vs. Flow
Table 6A Temperature Rise Applications
NKC110
Delta T
19.1°F
20°F
25°F
30°F
35°F
40°F
45°F
GPM
10.6
10.1
8.1
6.7
5.8
5.1
4.5
FT/HD
4.0
6.0
13.4
17.4
19.9
21.4
22.5
NKC150
Eq Ft of 1" Pipe
53
85
287
523
789
1085
1410
NKC199
FT/HD
4.0
9.6
13.1
Delta T
26.0°F
30°F
35°F
40°F
45°F
GPM
10.6
9.2
7.9
6.9
6.1
FT/HD
4.0
9.6
14.1
17.0
19.0
Eq Ft of 1" Pipe
53
162
317
490
679
Assumed Equivalent Lengths (1" Pipe)
Delta T
34.7°F
40°F
45°F
GPM
10.6
9.2
8.2
Eq Ft of 1" Pipe
53
162
277
Fitting / Component
90° Elbow
45° Elbow
Tee (straight run)
Tee (side port)
Ball Valve
Swing Check
Flow Check Valve (typical)
Y-Strainer
Eq Ft
2.5
1.0
0.5
4.5
4.3
4.5
54.0
4.5
NOTICE
All equivalent pipe lengths are based on the minimum pipe size of one inch.
NOTICE
The data provided takes into account the boiler and integral pump. Flow determination is based solely on
piping external to the boiler.
NOTICE
In Primary/Secondary, only the boiler loop is considered when determining flow. In full flow applications, all
piping and equipment must be considered.
35
™
FIRE TUBE COMBI
6A
Installation & Service Manual
Hydronic piping
Figure 6-2 Single Boiler - Primary / Secondary Piping
PRESSURE
REDUCING VALVE
WATER
METER
PRESSURE
GAUGE
BACKFLOW
PREVENTER
MAKE UP WATER
M
SYSTEM SUPPLY
SENSOR
(OPTIONAL)
AIR
SEPARATOR
MAY SUBSTITUTE LOW LOSS HEADER
TO
SYSTEM
BALL VALVE
(TYPICAL)
FROM
SYSTEM
NOT TO EXCEED 4 PIPE DIA OR MAX. OF 12" APART
SYSTEM
CIRCULATOR
Y-STRAINER
EXPANSION
TANK
DRAIN POINT
(TYPICAL)
CHECK
VALVE
BOILER
UNION
(TYPICAL)
TEMPERATURE /
PRESSURE
GAUGE
DRAIN
DIR #2000529680
NOTICE
DHW piping omitted for clarity.
NOTICE
Please note that these illustrations are meant to show system piping concept only, the installer is responsible
for all equipment and detailing required by local codes.
36
™
FIRE TUBE COMBI
6A
Hydronic piping
Installation & Service Manual
(continued)
Figure 6-3 Single Temperature Zoned with Circulators
ZONE #1
PRESSURE
REDUCING VALVE
WATER
METER
PRESSURE
GAUGE
ZONE #2 ZONE #3 ZONE #4
BACKFLOW
PREVENTER
FLOW CHECK
VALVE
(TYPICAL)
SYSTEM SUPPLY
SENSOR
(WHEN USED)
MAKE UP WATER
ZONE CIRCULATORS
(TYPICAL)
AIR SEPARATOR
EXPANSION
TANK
MAY SUBSTITUTE LOW LOSS HEADER
BALL VALVE
(TYPICAL)
Y-STRAINER
DRAIN POINT
(TYPICAL)
CHECK
VALVE
BOILER
TEMPERATURE /
PRESSURE
GAUGE
UNION
(TYPICAL)
DIR #2000533824
DRAIN
NOTICE
DHW piping omitted for clarity.
NOTICE
Please note that these illustrations are meant to show system piping concept only, the installer is responsible
for all equipment and detailing required by local codes.
37
Installation & Service Manual
™
FIRE TUBE COMBI
6A
Hydronic piping
Figure 6-4 Multiple Boilers - Single Temperature Zoned with Circulators
Model
110
150
199
2
3
Number of Units
4
5
6
7
Required Pipe Sizes
1"
1-1/4" 1-1/4" 1-1/2"
2"
1-1/2"
2"
2" 2-1/2" 2-1/2"
2"
2"
2-1/2" 2-1/2"
3"
2"
3"
3"
8
2"
3"
3-1/2"
ZONE #1
PRESSURE
REDUCING VALVE
WATER
METER
TEMPERATURE /
PRESSURE GAUGE
ZONE #2
BACKFLOW
PREVENTER
ZONE #3
ZONE #4
FLOW CHECK
VALVE
(TYPICAL)
MAKE UP
WATER
SYSTEM SUPPLY
SENSOR
(OPTIONAL)
AIR SEPARATOR
ZONE CIRCULATORS
(TYPICAL)
EXPANSION
TANK
BALL VALVE
(TYPICAL)
DRAIN POINT
(TYPICAL)
BOILER 2
MAY SUBSTITUTE LOW LOSS HEADER
NOT TO EXCEED 4 PIPE DIA OR MAX. OF 12" APART
Y-STRAINER
(TYPICAL)
BOILER 1
NOTICE:
CASCADE IS FOR
SPACE HEAT ONLY.
TEMPERATURE /
PRESSURE GAUGE
CAUTION
NOTICE
38
UNION
(TYPICAL)
DIR #2000529699
Mixing valves are required for the protection of low temperature loops.
Please note that these illustrations are meant to show system piping concept only, the installer is responsible
for all equipment and detailing required by local codes.
™
FIRE TUBE COMBI
6A
Hydronic piping
Installation & Service Manual
(continued)
Figure 6-5 Single Temperature Piped with Air Handler
PRESSURE
GAUGE
PRESSURE
REDUCING VALVE
BACKFLOW
PREVENTER
WATER
METER
MAKE UP
P WATER
WAT
WA
AIR
HANDLER
AIR SEPARATOR
EXPANSION
TANK
BALL VALVE
(TYPICAL)
Y-STRAINER
DRAIN POINT
(TYPICAL)
SYSTEM SUPPLY
SENSOR
(OPTIONAL)
BOILER
TEMPERATURE /
PRESSURE
GAUGE
DIR #2000530076 00
UNION
(TYPICAL)
NOTICE
DHW piping omitted for clarity.
NOTICE
Please note that these illustrations are meant to show system piping concept only, the installer is
responsible for all equipment and detailing required by local codes.
39
™
FIRE TUBE COMBI
6B
Installation & Service Manual
Domestic water piping
Scalding
Water chemistry
This combi heater can deliver scalding temperature water
at any faucet in the system. Be careful whenever using hot
water to avoid scalding injury. Certain appliances such as
dishwashers and automatic clothes washers may require
increased temperature water. By setting the thermostat
on this combi heater to obtain the increased temperature
water required by these appliances, you may create the
potential for scald injury. To protect against injury, you
MUST install an ASSE 1070 anti-scald mixing valve in the
water system. This valve will reduce point of discharge
temperature by mixing cold and hot water in branch
supply lines. Such valves are available from the local
plumbing supplier.
Any damage or failure resulting from improper water
chemistry, or heating anything other than potable water.
DEFINITION OF POTABLE WATER - Potable water
is defined as drinkable water supplied from utility or
well water in compliance with EPA secondary maximum
contaminant levels (40 CFR Part 143.3) as shown in Table
6C - Potable Water.
An ASSE 1070 anti-scald mixing
WARNING valve is REQUIRED. Failure to
comply could result in property
damage, severe injury, or death.
Table 6C Potable Water
Potable Water Levels
Contaminant
Level
Aluminum
Chloride
Color
Copper
Corrosivity
Fluoride
Foaming Agents
Iron
Manganese
Odor
pH
Silver
Sulfate
Total Dissolved Solids (TDS)
Zinc
0.05 to 0.2 mg/l
250 mg/l
15 color units
1.0 mg/l
Non-corrosive
2.0 mg/l
0.5 mg/l
0.3 mg/l
0.05 mg/l
3 threshold odor number
6.5 - 8.5
0.1 mg/l
250 mg/l
500 mg/l
5 mg/l
Near heater piping components
The following table (Table 6B) details the relationship of
water temperature and time with regard to scald injury
and may be used as a guide in determining the safest water
temperature for your applications.
Table 6B Approximate Time / Temperature Scald Chart
APPROXIMATE TIME / TEMPERATURE
RELATIONSHIPS IN SCALDS
120°F
125°F
130°F
135°F
140°F
145°F
150°F
155°F
More than 5 minutes
1 1/2 to 2 minutes
About 30 seconds
About 10 seconds
Less than 5 seconds
Less than 3 seconds
About 1 1/2 seconds
About 1 second
1. Recirculation pump (optional):
Field supplied. The recirculation pump shuts off flow
at the desired DHW set point.
2. Check valves:
Field supplied. Check valves are recommended for
installation as shown in FIG.’s 6-6 through 6-8. Failure
to install check valves could result in a reverse flow
condition during pump(s) off cycle.
3. Domestic hot water isolation valves:
Field supplied.
Full port ball valves are
required. Failure to use full port ball valves could
result in a restricted flow rate through the boiler.
4. Anti-scald mixing valve:
Field supplied. For use when utilizing the DHW option.
An ASSE 1070 anti-scald mixing valve is required.
5. Unions:
Field supplied. Recommended for unit serviceability.
6. Temperature and pressure gauge:
Field supplied. It is the responsibility of the contractor
to provide and install the temperature and pressure
gauge on the boiler water outlet.
40
7. Pressure relief valve:
Field supplied. The pressure relief valve is sized to
ASME specifications.
™
FIRE TUBE COMBI
6B
Domestic water piping
Installation & Service Manual
(continued)
Figure 6-6 Combi DHW Piping
BOILER
EXPANSION
TANK
UNION
(TYPICAL)
PRESSURE
RELIEF VALVE
(REQUIRED,
FIELD SUPPLIED)
ASSE 1070
ANTI-SCALD
MIXING VALVE
(REQUIRED)
H
M
C
FLOW
CHECK
TEMPERATURE /
PRESSURE GUAGE
HOT
WATER
SUPPLY
COLD
WATER
SUPPLY
DIR #2000534676 00
NOTICE
Hydronic piping omitted for clarity.
NOTICE
Please note that these illustrations are meant to show system piping concept only, the installer is
responsible for all equipment and detailing required by local codes.
An ASSE 1070 anti-scald mixing valve is REQUIRED. Failure to comply could result in property
WARNING damage, severe injury, or death.
41
™
FIRE TUBE COMBI
6B
Installation & Service Manual
Domestic water piping
Figure 6-7 DHW Recirculation w/Dedicated Return
BOILER
Note: Aquastat for DHW
recirculation pump or
thermostatic shut off valve must
be used to stop recirculation
water flow once the desired
temperature has been reached.
For best performance, Pre-Heat
Mode should be enabled when
using DHW recirculation.
EXPANSION
TANK
UNION
(TYPICAL)
PRESSURE
RELIEF VALVE
(REQUIRED,
FIELD SUPPLIED)
ASSE 1070
ANTI-SCALD
MIXING VALVE
(REQUIRED)
H
M
C
FLOW
CHECK
TEMPERATURE /
PRESSURE GAUGE
HOT WATER
FIXTURES
COLD
WATER
SUPPLY
AQUASTAT
RECIRCULATION
PUMP
NOTICE
Hydronic piping omitted for clarity.
DIR #2000534677 00
To prevent scalding from DHW recirculation temperature creep, a suitable method to stop recirculation
WARNING flow once water in the loop has reached the desired temperature must be used. Failure to stop water
flow once the desired DHW temperature has been reached can result in serious injury or death due to
scalding.
NOTICE
Please note that these illustrations are meant to show system piping concept only, the installer is
responsible for all equipment and detailing required by local codes.
An ASSE 1070 anti-scald mixing valve is REQUIRED. Failure to comply could result in property
WARNING damage, severe injury, or death.
42
Installation & Service Manual
™
FIRE TUBE COMBI
6B
Domestic water piping
(continued)
Figure 6-8 DHW Piping w/Recirculation Return Through Cold Line
BOILER
Note: Aquastat for DHW
recirculation pump or
thermostatic shut off valve must
be used to stop recirculation
water flow once the desired
temperature has been reached.
For best performance, Pre-Heat
Mode should be enabled when
using DHW recirculation.
EXPANSION
TANK
UNION
(TYPICAL)
PRESSURE
RELIEF VALVE
(REQUIRED,
FIELD SUPPLIED)
ASSE 1070
ANTI-SCALD
MIXING VALVE
(REQUIRED)
H
M
C
FLOW
CHECK
TEMPERATURE /
PRESSURE GAUGE
HOT WATER
FIXTURES
AQUASTAT
RECIRCULATION
PUMP
HOT
WATER
SUPPLY
COLD
WATER
SUPPLY
DIR #2000534675 00
NOTICE
Hydronic piping omitted for clarity.
To prevent scalding from DHW recirculation temperature creep, a suitable method to stop recirculation
WARNING flow once water in the loop has reached the desired temperature must be used. Failure to stop water
NOTICE
flow once the desired DHW temperature has been reached can result in serious injury or death due to
scalding.
Please note that these illustrations are meant to show system piping concept only, the installer is
responsible for all equipment and detailing required by local codes.
An ASSE 1070 anti-scald mixing valve is REQUIRED. Failure to comply could result in property
WARNING damage, severe injury, or death.
43
™
FIRE TUBE COMBI
7
Installation & Service Manual
Gas connections
Connecting gas supply piping
1. Remove the front access panel and refer to FIG. 7-1
to pipe gas to the boiler.
a. Install a field supplied sediment trap / drip leg
upstream of the boiler gas controls.
2. Support piping with hangers, not by the boiler or its
accessories.
WARNING
Figure 7-1 Gas Supply Piping
The gas valve and blower will not support
the weight of the piping. Do not attempt
to support the weight of the piping with the
boiler or its accessories. Failure to comply
could result in severe personal injury, death,
or substantial property damage.
3. Purge all air from the gas supply piping.
4. Before placing the boiler in operation, check the boiler and
its gas connection for leaks.
a. Close manual main shutoff valve during any
pressure testing at more than 14 inches w.c.
b. Disconnect the boiler and gas valve from the gas
supply piping during any pressure testing greater
than 14 inches w.c.
WARNING
MANUAL SHUTOFF VALVE
UNION
GAS SUPPLY
DRIP LEG
DIR #2000528364 00
44
Do not check for gas leaks with an open
flame – use the bubble test. Failure to
use the bubble test or check for gas leaks
can cause severe personal injury, death, or
substantial property damage.
5. Use pipe sealing compound compatible with propane gases.
Apply sparingly only to male threads of the pipe joints so
that pipe dope does not block gas flow.
Installation & Service Manual
™
FIRE TUBE COMBI
7
Gas connections
WARNING
(continued)
Failure to apply pipe sealing compound
as detailed in this manual can result
in severe personal injury, death, or
substantial property damage.
WARNING Noble Combi Boilers are typically
shipped ready to fire on natural gas.
Check boiler rating plate to determine
which fuel the boiler is set for. If set to
natural gas, it may be converted to LP
by installing an LP venturi (see page
12). In order to operate on LP gas, an
LP venturi MUST BE installed. Failure
to comply could result in severe personal
injury, death, or substantial property
damage.
WARNING
Use two wrenches when tightening gas
piping at boiler (FIG. 7-2), using one
wrench to prevent the boiler gas line
connection from turning. Failure to
support the boiler gas connection pipe
to prevent it from turning could damage
gas line components.
Natural gas:
Pipe sizing for natural gas
1. Refer to Table 7A for pipe length and diameter. Based on
rated boiler input (divide by 1,000 to obtain cubic feet per
hour).
a. Table 7A is only for natural gas with specific gravity
0.60 inches, with a pressure drop through the gas
piping of 0.3 inches w.c.
b. For additional gas pipe sizing information, refer to
ANSI Z223.1 (or B149.1 for Canadian installations).
Natural gas supply pressure requirements
1. Pressure required at the gas valve inlet pressure port:
• Maximum 14 inches w.c. with no flow (lockup) or with
boiler on.
• Minimum 4 inches w.c. with gas flowing (verify during
boiler startup).
2. Install 100% lockup gas pressure regulator in supply line if
inlet pressure can exceed 14 inches w.c. at any time. Adjust
lockup regulator for 14 inches w.c. maximum.
Propane Gas:
Figure 7-2 Inlet Pipe with Backup Wrench
WARNING
Noble Combi Boilers are typically shipped
ready to fire on natural gas. Check boiler
rating plate to determine which fuel the
boiler is set for. If set to natural gas, it may
be converted to LP by installing an LP venturi
(see page 12). In order to operate on LP gas,
an LP venturi MUST BE installed. Failure to
comply could result in severe personal injury,
death, or substantial property damage.
Pipe sizing for propane gas
1. Contact gas supplier to size pipes, tanks, and 100%
lockup gas pressure regulator.
USE BACK UP WRENCH
TO PREVENT PIPE FROM
ROTATING
Propane Supply Pressure Requirements
DIR #2000528388 00
NOTICE
Maximum inlet gas pressure must not
exceed the value specified. Minimum
value listed is for the purposes of input
adjustment.
1. Adjust propane supply regulator provided by the gas
supplier for 14 inches w.c. maximum pressure.
2. Pressure required at gas valve inlet pressure port:
• Maximum 14 inches w.c. with no flow (lockup) or with
boiler on.
• Minimum 8 inches w.c. with gas flowing (verify during
boiler startup).
WARNING
Ensure that the high gas pressure regulator
is at least 6 - 10 feet upstream of the
appliance.
45
™
FIRE TUBE COMBI
7
Installation & Service Manual
Gas connections
Table 7A Natural Gas Pipe Size Chart
Capacity of Schedule 40 Metallic Pipe in Cubic Feet of Natural Gas Per Hour
(based on .60 specific gravity, 0.30" w.c. pressure drop)
Pipe
Size
(Inches)
10
1/2
131
90
72
3/4
1
1 1/4
273
514
1,060
188
353
726
151
284
583
1 1/2
1,580
1,090
873
2
3,050
2,090
1,680
Length of Pipe in Straight Feet
20
30
40
50
60
70
80
90
100
125
150
175
200
62
55
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
129
243
499
114
215
442
104
195
400
95
179
368
89
167
343
83
157
322
79
148
304
70
131
269
63
119
244
58
109
224
N/A
102
209
747
662
600
552
514
482
455
403
366
336
313
1,440
1,280
1,160
1,060
989
928
877
777
704
648
602
2 1/2
4,860
3,340
2,680
2,290
2,030
1,840
1,690
1,580
1,480
1,400
1,240
1,120
1,030
960
3
8,580
5,900
4,740
4,050
3,590
3,260
3,000
2,790
2,610
2,470
2,190
1,980
1,820
1,700
4
17,500 12,000
9,660
8,270
7,330
6,640
6,110
5,680
5,330
5,040
4,460
4,050
3,720
3,460
WARNING
Noble Combi Boilers are typically shipped ready to fire on natural gas. Check boiler rating plate to determine
which fuel the boiler is set for. If set to natural gas, it may be converted to LP by installing an LP venturi (see
page 12). In order to operate on LP gas, an LP venturi MUST BE installed. Failure to comply could result
in severe personal injury, death, or substantial property damage.
Check inlet gas supply
CSA or UL listed flexible gas connections
NOTICE
are acceptable, but you must exercise
caution to ensure that the line has
adequate capacity to allow your boiler
to fire at full rate. Consult with local
codes for proper installation or service
procedures.
DO NOT adjust gas valve outlet
WARNING
pressure. The gas valve is factory-set
for the correct outlet pressure. This
setting is suitable for natural gas and
propane, requiring no field adjustment.
Attempting to alter the gas valve outlet
pressure could result in damage to the
valve, causing potential severe personal
injury, death, or substantial property
damage.
The gas piping must be sized for the proper flow and length
of pipe, to avoid excessive pressure drop. Both the gas
meter and the gas regulator must be properly sized for the
total gas load.
If you experience a pressure drop greater than 1 inch w.c.,
the meter, regulator, or gas line is undersized or in need of
service. Perform the steps below when checking inlet gas
supply:
1.
Shut OFF power at source.
2.
Shut off gas supply at the manual gas valve in the gas
piping to the appliance.
46
3.
4.
5.
Loosen the set screw one (1) full turn from inside the
pressure tap on top of the gas valve. Place the tubing of
the manometer over the tap once the set screw is
loosened as shown in FIG. 7-3.
Slowly turn on the gas supply at the field installed
manual gas valve.
Turn ON power at source.
6.
Press and hold the RIGHT and DOWN buttons
simultaneously for five (5) seconds to place the boiler into
Service Mode. In Service Mode, the boiler will fire at
ignition speed and will then modulate up to full fire.
7.
Adjust the temperature set point on the control panel of
the boiler control module to call for heat.
8.
Observe the gas supply pressure as the burner fires at
100% of rated input. Percent of burner input will be
displayed on the control panel.
9.
Ensure inlet pressure is within specified range.
Minimum and maximum gas supply pressures are
specified in this section of the manual.
10. If gas supply pressure is within normal range and no
adjustments are needed, proceed on to Step 11.
11. If the gas pressure is out of range, contact the gas utility,
gas supplier, qualified installer or service agency to
determine the necessary steps to provide proper gas
pressure to the control.
12. Exit Service Mode.
13. Turn OFF power at source.
™
FIRE TUBE COMBI
7
Gas connections
(continued)
14. Shut off the gas supply at the manual gas valve in the gas
piping to the appliance.
15. Remove the manometer from the pressure tap on top of
the gas valve. Re-tighten the set screw inside the pressure
tap.
WARNING
Installation & Service Manual
When re-tightening the set screw, be
sure to tighten securely to prevent gas
leaks.
Do not check for gas leaks with an open
flame -- use the bubble test. Failure to
use the bubble test or check for gas leaks
can cause severe personal injury, death,
or substantial property damage.
Gas Pressure
The gas pressure must remain between 4 inches w.c. (natural),
8 inches w.c. (LP) minimum and 14 inches w.c. (natural and
LP) maximum during stand-by (static) mode and while in
operating (dynamic) mode. If an in-line regulator is used, it
must be a minimum of 10 feet from the Noble Combi Boiler. It
is very important that the gas line is properly purged by the gas
supplier or utility company. Failure to properly purge the lines
or improper line sizing, will result in ignition failure.
The problem is especially noticeable in NEW LP installations
and also in empty tank situations. This can also occur when
a utility company shuts off service to an area to provide
maintenance to their lines.
16. Turn on the gas supply at the manual gas valve.
Gas valve replacement
17. Turn ON power at source.
The gas valve MUST NOT be replaced with a conventional gas
valve under any circumstances.
18. Adjust the temperature set point on the control panel
of the boiler control module to the desired
water temperature so the appliance will call for heat.
19. Check burner performance by cycling the system while
you observe burner response. The burner should
ignite promptly. Flame pattern should be stable. Turn
system off and allow burner to cool, then cycle burner
again to ensure proper ignition and flame
characteristics.
WARNING
Failure to follow all precautions could
result in fire, explosion, or death!
WARNING
DO NOT adjust gas valve outlet pressure.
The gas valve is factory-set for the correct
outlet pressure. This setting is suitable
for natural gas and propane, requiring
no field adjustment. Attempting to
alter the gas valve outlet pressure could
result in damage to the valve, causing
potential severe personal injury, death, or
substantial property damage.
Figure 7-3 Inlet Gas Supply Check
DETAIL A
LOOSEN SET SCREW
ONE (1) FULL TURN
THEN PLACE TUBING
OVER PRESSURE
TAP
A
DIR #2000529636 00
47
Installation & Service Manual
™
FIRE TUBE COMBI
8
Field wiring
NOTICE
WARNING
NOTICE
For field wiring on Combi units, reference
the Combi Installation and Service
Manual provided with the unit.
ELECTRICAL SHOCK HAZARD – For
your safety, turn off electrical power supply
before making any electrical connections
to avoid possible electric shock hazard.
Failure to do so can cause severe personal
injury or death.
Wiring must be N.E.C. Class 1.
If original wiring as supplied with boiler
must be replaced, use only type 105°C
wire or equivalent.
Boiler must be electrically grounded as
required by National Electrical Code
ANSI/NFPA 70 – latest edition.
CAUTION
Label all wires prior to disconnection when
servicing controls. Wiring errors can
cause improper and dangerous operation.
Figure 8-1 Remove Metal Junction Box Cover
Installation must comply with:
1. National Electrical Code and any other national, state,
provincial, or local codes, or regulations.
2. In Canada, CSA C22.1 Canadian Electrical Code Part 1,
and any local codes.
Line voltage connections
1. Remove the cover of the metal junction box as shown in
FIG. 8-1.
2. Connect 120 vac power wiring using wire nuts (field
supplied) to the labeled line voltage terminal wires in the
junction box.
3. Provide and install a fused disconnect or service switch
(15 amp recommended) as required by the code.
4. To activate a system pump, wire as shown in FIG. 8-2. If
the motor is larger than 2 amps, you must isolate with a
relay.
Low voltage connections
1. Route all low voltage wires through the holes in the bottom
front right side, just under the control panel, as shown in
FIG. 8-3.
2. Connect low voltage wiring to low voltage connection
board as shown in FIG. 8-4 on page 50 of this manual and
the boiler wiring diagram.
NOTICE
Do not run low voltage wires next to high
voltage wires in the same conduit.
HIGH VOLTAGE
JUNCTION BOX
DIR #2000529321 00
Figure 8-2 Line Voltage Field Wiring Connections
Figure 8-3 Routing Field Wiring
SYSTEM PUMP
(OPTIONAL)
LOW VOLTAGE
CONNECTION
BOARD
DIR #2000536085 00
DIR #2000529643 00
LOW VOLTAGE
WIRING HOLES
48
™
FIRE TUBE COMBI
8
Field wiring
Installation & Service Manual
(continued)
Thermostat
System supply sensor
1. Connect the room thermostat or end switch (isolated
contact only) to the room thermostat as shown in FIG.
8-4.
1. By installing the optional system supply sensor into the
supply of the primary loop, the temperature of the primary
supply can be controlled. The boiler control automatically
detects the presence of this sensor, and controls the boiler
firing rate to maintain the system supply temperature to the
set point.
Do not install the system supply sensor into
CAUTION
the system return.
2. Install the thermostat on the inside wall, away from
influences of drafts, hot or cold water pipes, lighting
fixtures, televisions, sunlight or fireplaces.
3. Thermostat anticipator (if applicable):
a. If connected directly to boiler, set for 0.1 amps.
b. If connected to relays or other devices, set to match
total electrical power requirements of connected
devices. See device manufacturers’ specifications
and thermostat instructions for details.
Outdoor temperature sensor
In accordance with the United States Energy Policy and
Conservation Act, this boiler is equipped with outdoor air
reset, a feature that saves energy by reducing boiler water
temperature as heating load decreases. To use this feature,
the outdoor air sensor provided with the boiler must be
properly installed.
1.
Mount the sensor on an exterior wall, shielded from
direct sunlight or flow of heat or cooling from other
sources.
2. Route sensor wires through a designated wiring hole in
the bottom front right side of the boiler (see FIG. 8-3).
3. Connect outdoor temperature sensor (FIG. 8-4) to the
outdoor sensor terminals on the connection board to
enable outdoor reset operation of the Noble Combi
Boiler.
2. The 100170581 sensor provided with the boiler must be
used for the system sensor.
3. Connect the system supply sensor to these terminals (FIG.
8-4).
Wiring of the cascade
When wiring the boilers for Cascade operation, select one boiler
as the Leader boiler. The remaining boilers will be designated as
Members.
Connect the system supply sensor and outdoor air sensor (if
used) to the Leader boiler. For the Cascade system to work
properly the system supply sensor must be installed. The
location of the system supply sensor should be downstream
of the boiler connections in the main system loop. The system
supply sensor should be wired to the Low Voltage Connection
Board at the terminals marked for the system sensor (see FIG.
8-4). The Leader control will use the water temperature at the
system supply sensor to control the operation of the Cascade.
Auxiliary limit switch
A field supplied auxiliary limit switch can be used for the gas
pressure switch. When installing the auxiliary limit switch,
please follow the kit instructions provided with the switch
and then proceed as follows:
1. If the auxiliary switch is mounted to the exterior of the
boiler, run the wires through a knockout in the bottom
front right side of the boiler. If the auxiliary limit switch
is mounted on the interior of the boiler, route the wires
to the connection board.
2. Once the wires are inside the boiler and near the
connection board, connect the wires to the auxiliary
limit switch terminals.
Air handler contacts
A set of un-powered contacts are available on the low voltage
connection board (FIG. 8-4) that can be used to turn off the
fan on an air handler when the diverter valve is in the DHW
position and therefore not providing hot water to the space
heating system. These contacts are normally open and will
close when the diverter valve is in the space heat position.
49
50
DIR #2000534741 00
ROOM THERMOSTAT
(FIELD SUPPLIED)
™
AUXILIARY LIMIT
(FIELD SUPPLIED)
LOW WATER
CUT OFF
(OPTIONAL)
8
SYSTEM SUPPLY SENSOR
OUTDOOR SENSOR
FIRE TUBE COMBI
Installation & Service Manual
Field wiring
Figure 8-4 Low Voltage Field Wiring Connections
™
FIRE TUBE COMBI
9
Installation & Service Manual
Condensate disposal
Condensate drain
NOTICE
Use materials approved by the authority
having jurisdiction. In the absence of other
authority, PVC and CPVC pipe must comply
with ASTM D1785 or D2845. Cement and
primer must comply with ASME D2564 or
F493. For Canada use CSA or ULC certified
PVC or CPVC pipe, fittings, and cement.
NOTICE
To allow for proper drainage on large
horizontal runs, a second line vent may be
required and tubing size may need to increase
to 1 inch.
1. This boiler is a high efficiency appliance that produces
condensate.
2. The bottom of the boiler has a 3/4 inch pipe for connection
of a 3/4 inch PVC pipe (FIG. 9-1).
3. Slope condensate tubing down and away from the boiler
into a drain or condensate neutralizing filter. Condensate
from the Noble Combi Boiler will be slightly acidic
(typically with a pH from 3 to 5). Install a neutralizing
filter if required by local codes.
A Neutralizer Kit is available from the factory.
4. Do not expose condensate line to freezing temperatures.
5. Use only plastic tubing or piping as a condensate drain
line (FIG. 9-1).
The condensate line must remain
unobstructed, allowing free flow of
condensate. If condensate is allowed to
freeze in the line or if the line is obstructed in
any other manner, condensate can exit from
the boiler tee, resulting in potential water
damage to property.
6. A condensate removal pump is required if the boiler is
below the drain. When installing a condensate pump, select
one approved for use with condensing boilers and furnaces.
The pump should have an overflow switch to prevent
property damage from condensate spillage.
Figure 9-1 Condensate Disposal
51
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FIRE TUBE COMBI
10
Start-up
Pre-Commissioning Cleaning
1. Prior to fill and start-up, flush the entire heating system.
2. Clean the entire heating system with an approved precommissioning cleaner (comparable to Sentinel X300
or Fernox F3) in accordance with the manufacturer’s
recommendation to remove debris and prolong the life of
the heat exchanger.
3. Clean all water filtering devices in the system.
Boiler water
Do not use petroleum based cleaning or
CAUTION sealing compounds in the boiler system.
Gaskets and seals in the system may be
damaged. This can result in substantial
property damage.
DO NOT use "homemade cures" or "boiler
CAUTION patent medicines". Serious damage to
boiler, personnel, and/or property may
result.
4. Flush the cleaning solution out of the entire system and
refill.
Fill water
Check/control fill water chemistry
IMPORTANT
Table 10A Boiler Water Chemistry
BOILER WATER CHEMISTRY
Conduct water quality testing prior to
installing the appliance. Various solutions
are available to adjust water quality.
The manufacturer recommends the following for properly
filling your boiler with the appropriate water chemistry for
closed loop boilers. Good fill water quality will help extend
the life of the appliance by reducing the effects of lime scale
buildup and corrosion in closed loop systems.
Hardness between 5 and 12 grains per gallon
1. Consult local water treatment companies for hard water
areas (above 12 grains per gallon hardness).
2. Hardness levels that are above 12 grains/gallon can lead
to lime scale buildup throughout the boiler system. If the
fill water is below 5 grains/gallons, usually due to use of a
water softener, it is recommended to mix in some potable
water at the inlet to increase the hardness of the water to
above 5 grains/gallons.
pH between 6.5 and 8.5
Specification
Dissolved Solids
2. The greater the amounts of TDS present, the higher the
corrosion potential due to increased conductivity in the
water.
Chlorine concentration less than 150 ppm
1. Do not fill boiler or operate with water containing
chlorine in excess of 150 ppm.
2. Filling with fresh drinking water should be acceptable.
3. Do not use the boiler to directly heat swimming pool or
spa water.
< 2000 ppm
pH Level
6.5 to 9.5
Chloride
< 150 ppm
Monitoring pH, chlorides, TDS, and hardness
levels can prolong the life of the appliance by reducing
lime scale buildup, corrosion, and erosion. Check for
leaks to ensure that fresh water is not entering the
system.
•
Continual fresh makeup water will reduce boiler life.
•
Mineral buildup in the heat exchanger reduces heat
transfer, overheats the stainless steel heat exchanger,
and causes failure.
•
The addition of oxygen carried in by makeup water
can cause internal corrosion in system components.
•
Leaks in the boiler or piping must be repaired at
once to prevent excessive makeup water. For this
purpose, it is recommended to install a water meter
to easily check the amount of makeup water entering
the system. Makeup water volume should not exceed
5% of the total system volume per year. NOTE: When
makeup water is added, make sure the chemical
additives are added to maintain the correct level.
•
An approved multi-metal corrosion inhibitor
(comparable to Sentinel X100 or Fernox F1) is
recommended at the correct concentration and in the
manner recommended by the manufacturer.
Total Dissolved Solids (TDS) less than 350 ppm
1. Total dissolved solids are all minerals, salts, metals, and
charged particles that are dissolved in water.
Range
•
1. pH levels below 6.5 can cause an increase in the rate of
corrosion. pH of 8.5 or higher can potentially cause lime
scale buildup.
52
Installation & Service Manual
Freeze protection
WARNING Ethylene glycol is toxic, DO NOT use as
your freeze protection. Ethylene glycol has a
sweet aroma which children and pets could
mistake as food and ingest; leading to death.
™
FIRE TUBE COMBI
10
Start-up
Installation & Service Manual
(continued)
1.
Use glycol only if needed for freeze protection.
Fill and test water system
2.
Propylene glycol is the recommended freeze protection.
3.
Make sure to flush the boiler system before adding glycol.
1. Fill system only after ensuring the water meets the
requirements of this manual.
4.
Determine the freeze protection fluid quantity using
system water content, following the fluid manufacturer's
instructions. Boiler water content is listed on page 6.
Remember to include expansion tank water content.
5. Local codes may require a backflow preventer or actual
disconnect from city water supply.
6. When using freeze protection fluid with automatic fill, it is
suggested to install a water meter to monitor water makeup.
Freeze protection fluid may leak before the water begins to
leak, causing the concentration to drop, which reduces the
freeze protection level.
7. The freeze protection set points may be lowered when freeze
protection fluid is used (see the Noble Service Manual).
8. Consult the glycol manufacturer for details on the suggested
mix of glycol and water for the desired freeze protection
level and the de-rate effect it will have on the boiler output.
Test / replace freeze protection fluid
1. For systems using freeze protection fluids, follow the fluid
manufacturer's instructions.
2. Freeze protection fluid must be replaced periodically due to
degradation of inhibitors over time.
3. It is recommended to test the glycol concentration annually
and adjust within the desired set points.
Oxygen prevention
CAUTION
Eliminate all system leaks. Continual
fresh makeup water will reduce boiler
life. Minerals can build up in the
heat exchanger, reducing heat transfer,
overheating the heat exchanger, and
causing heat exchanger failure.
Dissolved oxygen can have a negative effect on the boiler
system. Oxygen can cause iron oxide to generate iron
deposits. Oxygen may also increase the rate of corrosion
on non-stainless steel parts of the system. A low pH level
combined with oxygen further enhances its corrosive effects.
After boiler installation, check for air leaks in the following
areas:
• Suction gasket
• Pump
• Air valve
• O-ring gaskets
Precautions include installing a water meter to evaluate the
fresh water volume entering the system (should be no more
than 5% system volume). Additional volumes of fresh water
could indicate that a leak is present.
2. Close automatic and manual air vents and boiler drain
valve.
3. Fill to correct system pressure. Correct pressure will vary
with each application.
a. The minimum cold water fill pressure for a system is
12 psi.
b. Pressure will rise when the boiler is turned ON and
system water temperature increases.
4. At initial fill and during boiler startup and testing, check
the system thoroughly for any leaks. Repair all leaks before
proceeding further.
Purge air from water system
1. Purge air from system:
a. Connect a hose to the purge valve. Route the hose to
an area where water can drain and be seen.
b. Close the boiler or system isolation valve between the
purge valve and fill connection to the system.
c. Close zone isolation valves.
d. Open the quick-fill valve on the cold water makeup
line.
e. Open purge valve.
f. Open the isolation valves one zone at a time. Allow
water to run through the zone, pushing out the air.
Run until no noticeable air flow is present. Close
the zone isolation valves and proceed with the next
zone. Follow this procedure until all zones are purged.
g. Close the quick-fill water valve and purge valve and
remove the hose. Open all isolation valves. Watch that
system pressure rises to correct cold-fill pressure.
h. After the system has operated for a while, eliminate
any residual air by using the manual air vents located
throughout the system.
i. If purge valves are not installed in the system, open the
manual air vents in the system one at a time, beginning
with the lowest floor. Close the vent when water
squirts out. Repeat with remaining vents.
2. Open the automatic air vent (diaphragm-type or bladder
type expansion tank systems only) one turn.
3. Open other vents:
a. Starting on the lowest floor, open air vents one at a
time until water squirts out.
b. Repeat with remaining vents.
4. Refill to correct pressure.
53
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FIRE TUBE COMBI
10
Installation & Service Manual
Start-up
Check for gas leaks
Before starting the boiler, and during
initial operation, smell near the floor and
around the boiler for gas odorant or any
unusual odor. Remove the front access
panel and smell the interior of the boiler
enclosure. Do not proceed with startup
if there is any indication of a gas leak.
Use an approved leak detection solution.
Repair any leaks at once.
WARNING DO NOT adjust gas valve outlet pressure.
The gas valve is factory set for the correct
outlet pressure. This setting is suitable
for natural gas and propane, requiring
no field adjustment. Attempting to
alter the gas valve outlet pressure could
result in damage to the valve, causing
potential severe personal injury, death, or
substantial property damage.
Propane boilers only – Your propane
WARNING
supplier mixes an odorant with the propane
to make its presence detectable. In some
instances, the odorant can fade, and the
gas may no longer have an odor. Before
startup (and periodically thereafter), have
the propane supplier verify the correct
odorant level in the gas.
WARNING
Check thermostat circuit(s)
1. Disconnect the external wire connected to the room
thermostat terminal on the connection board.
2. Connect a voltmeter across these two incoming wires.
Close each thermostat, zone valve, and relay in the external
circuit one at a time and check the voltmeter reading across
the incoming wires.
3. There should NEVER be a voltage reading.
4. If a voltage does occur under any condition, check and
correct the external wiring. (This is a common problem
when using 3-wire zone valves.)
5. Once the external thermostat circuit wiring is checked and
corrected if necessary, reconnect the external thermostat
circuit wires to the connection board.
Inspect condensate system
Inspect/check condensate lines and fittings
Inspect the condensate drain line, condensate PVC fittings and
condensate trap (FIG. 10-1).
Clean/Inspect Trap Assembly
Remove the clean out cap on the bottom of the trap. Let the
condensate and any debris drain out.
Figure 10-1 Condensate Trap
HOSE BARB
MOUNTING NUT
FLOAT BALL
CONDENSATE
DRAIN
REMOVABLE CAP
TO CLEAN OUT TRAP
DIR #2000529332 00
54
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FIRE TUBE COMBI
10
Start-up
Installation & Service Manual
(continued)
Final checks before starting the boiler
 Check gas piping
 Read this manual to familiarize yourself with boiler
control module operation. Reference page 56 for proper
steps to start boiler.
1. Check around the boiler for gas odor following the
procedure on page 44 of this manual (connecting gas supply
piping).
 Verify the boiler and system are full of water and all
system components are correctly set for operation.
WARNING
 Verify the preparation procedures of Section 10, pages
52 - 54 have been completed.
 Verify electrical connections are correct and securely
attached.
 Inspect vent piping and air piping for signs of deterioration
from corrosion, physical damage or sagging. Verify air
piping and vent piping are intact and correctly installed
per this manual.
Start the boiler
 Propane boilers – verify conversion
1. Verify propane conversion has been completed per the
Propane Conversion instructions.
WARNING
DO NOT adjust gas valve outlet pressure.
The gas valve is factory-set for the correct
outlet pressure. This setting is suitable
for natural gas and propane, requiring
no field adjustment. Attempting to alter
the gas valve outlet pressure could result
in damage to the valve, causing potential
severe personal injury, death, or substantial
property damage.
WARNING
Noble Combi Boilers are typically shipped
ready to fire on natural gas. Check boiler
rating plate to determine which fuel the
boiler is set for. If set to natural gas, it
may be converted to LP by installing an
LP venturi (see page 12). In order to
operate on LP gas, an LP venturi MUST BE
installed. Failure to comply could result in
severe personal injury, death, or substantial
property damage.
1. Read and follow the Operating instructions in FIG. 10-2,
page 56.
If boiler does not start correctly
1. Check for loose connections, blown fuse or service switch
off?
2. Is boiler water temperature above 200°F?
3. Is thermostat set below room temperature?
4. Is gas turned on at meter or boiler?
5. Is incoming gas pressure less than 4 inches w.c.?
If none of the above corrects the problem, refer to the
Troubleshooting Section.
Check system and boiler
 Check water piping
1. Check system piping for leaks. If found, shut down
the boiler and repair immediately. (See WARNINGS
on pages 52 and 54 (startup) regarding failure to repair
leaks.)
If you discover evidence of any gas leak,
shut down the boiler at once. Find the
leak source with a bubble test and repair
immediately. Do not start the boiler again
until corrected. Failure to comply could
result in severe personal injury, death, or
substantial property damage.
2. Vent any remaining air from the system using manual
vents. Air in the system will interfere with circulation
and cause heat distribution problems and noise.
3. Ensure an ASSE 1070 anti-scald mixing valve is installed
on the outlet of the domestic hot water piping.
 Check vent piping and air piping
1. Check for gastight seal at every connection, seam of air
piping, and vent piping.
WARNING
Venting system must be sealed gastight
to prevent flue gas spillage and carbon
monoxide emissions, which will result in
severe personal injury or death.
55
™
FIRE TUBE COMBI
10
Installation & Service Manual
Start-up
Figure 10-2 Operating Instructions
Move switch to the “OFF” position.
56
™
FIRE TUBE COMBI
10
Start-up
Installation & Service Manual
(continued)
Noble Combi Boiler control module
Use the control panel (FIG. 10-3) to set temperatures, operating conditions, and monitor boiler operation.
Figure 10-3 Control Panel
RESET BUTTON
DISPLAY
WINDOW
- Indicates that the unit has a Space Heating demand.
- Indicates that the unit has a DHW demand. This icon will flash if
the unit has a Pre-heat demand (if enabled). (Combi Only)
UP BUTTON
- Indicates that the integral boiler pump is running. This pump is
used for both Space Heating and DHW demands.
DOWN BUTTON
2
- Indicates the burner is firing and a flame signal is detected.
- Indicates that the system pump contacts are being powered.
- Indicates that the unit is running in Service Mode.
- Indicates that Freeze Protection is active.
LEFT BUTTON
RIGHT BUTTON
Home screen
The Home Screen can be used to view the current operating information of the Noble Combi Boiler. The ▲ and ▼ buttons can
be used to page through the screen sequence, displaying various operating statistics.
Figure 10-4 Screen Sequence
57
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FIRE TUBE COMBI
10
Start-up
Setup wizard
- MAX SH SETPT
•
The Noble Combi Boiler control has a Setup Wizard feature
that can be used to help with the initial start-up of the unit.
This Setup Wizard will walk an installer through the most
commonly required parameters.
The Setup Wizard is automatically accessed the first time the
unit is powered up from the factory and will allow setting
of certain parameters without the need to enter the installer
password. Once the Setup Wizard is completed or canceled,
it can only be accessed again by going through the Installer
Menu.
•
•
OUTDOOR TEMP COLDEST DAY
• When outdoor reset is used, this is the outdoor
temperature used on the reset curve corresponding to the
SPACE HEAT SETPT (COLDEST DAY). This parameter
should be set to the outdoor temperature used in the heat
load calculation for the cold design day.
• Range: -40°F – 75°F
• Default: 10°F
-
OUTDOOR TEMP – WARM WEATHER SHUTDOWN
•
•
•
Button functions in the setup wizard
◄
- Change value of current parameter
- Move to the next parameter or finish Setup
Wizard on last parameter
- Save changes and exit the Setup Wizard. This
will bypass the remaining parameters in the
Wizard.
AUTO RESET HI LIMIT
• When the outlet temperature exceeds the Automatic
Reset High Limit setting, automatic high limit
action occurs. The boiler shuts down until the
outlet water temperature cools below 10°F under
this setting and a 60 second timer has elapsed. Note
that this setting applies to both SH and DHW
Modes.
• Range: 32°F – 200°F
• Default: 200°F
-
MAN. RESET HI LIMIT
• If the outlet temperature continues to increase after
automatic reset high limit action, the Manual Reset
High Limit action occurs when the outlet water
temperature exceeds this setting. This will require
a manual reset before operation can resume. Note
that this setting applies to both SH and DHW
Modes.
• Range: 32°F – 210°F
• Default: 210°F
Parameters in the setup wizard
58
When the outdoor temperature rises above this
point, the control will block all space heating
demands (DHW demands will still be active).
Space heating operation will resume when outdoor
temperature falls 10°F below this point.
Range: 32°F – 104°F
Default: 70°F
-
To exit the menu without saving changes, you must cycle
power to the unit before exiting the menu.
- TIME/DATE
- SPACE HEAT SETPT (COLDEST DAY)
• This is the space heating water temperature set
point that will be used in Space Heating Mode.
If outdoor reset is used, this parameter represents
the water temperature on the reset curve
corresponding to the coldest day outdoor
temperature. When outdoor reset is in use, if
outdoor temperature falls below the OUTDOOR
TEMP COLDEST DAY parameter, space heating
set point can go higher than this setting.
• Range: 68°F – MAX SH SETPT (185°F by default)
• Default: 125°F
The MAX SH SETPT should be set to the highest space
heating water set point that can be used for the specific
space heating system. This parameter is the upper limit
of what the user can adjust the SH SETPT (COLD DAY)
parameter to. This parameter also serves as a limit of
space heat set point that can be generated by the outdoor
reset curve in the event that outdoor temperature falls
below the coldest day outdoor temperature setting.
Range: 60°F – 190°F
Default: 185°F
-
Figure 10-5 Installer Menu
▲/▼
►
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FIRE TUBE COMBI
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Start-up
(continued)
-
DHW SETPT
• This is the desired set point temperature of
Domestic Hot Water (DHW) generated by the
unit. Note that the required anti-scald mixing
valve will likely require a setting greater than the
desired DHW temperature.
• Range: 60°F – MAX DHW SETPT
• Default: 120°F
-
SPACE HEAT RATE LIMITING
• This feature is used when the maximum space
heating load is less than the maximum input
rating of the unit. This setting will limit the
maximum input rate of the unit for a space
heating demand only (DHW demands will not
be limited).
• Range: 10% – 100%
• Default: 100%
COMBI PRE-HEAT
• The Combi Pre-Heat function can be used to
improve DHW performance and comfort by
maintaining boiler water at an elevated
temperature to be able to immediately serve a
DHW demand. In certain applications, the PreHeat function can also reduce water usage
compared to not using Pre-Heat. Enabling
Pre-Heat, however, can increase fuel usage as the
unit will periodically fire to maintain heated
water.
• Settings: ENABLED/DISABLED
• Default: ENABLED
-
Installation & Service Manual
Figure 10-6 Service Menu
Button functions in Service Mode
▲/▼ - Change the target fan speed in increments of 100 rpm.
►
- Toggle between operating at high fire and low fire.
◄
- Exit Service Mode and return to the Home Screen.
Check flame and combustion
1. Turn the main power off to the boiler.
2. Remove the flue plug from the vent pipe adapter.
Note: Combustion measurements will be made at this
point.
Figure 10-7 Flue Plug Removal
Service mode
Entering
Service
Mode
will
WARNING immediately cause the boiler to
fire. Failure to ensure that the unit
is fully assembled and installed and
in safe working condition; including
having properly installed venting, all
air purged from the heat exchanger,
and with proper water supply and
flow, can result in serious injury,
death, significant property damage, or
destruction of the heater.
REMOVE THE FLUE PLUG
FROM THE VENT PIPE
ADAPTER
DIR #2000534695 00
The Noble Combi Boiler includes a Service Mode feature that
can be used to force the unit to run at a particular firing rate.
This feature can be used by qualified service technicians for
adjusting combustion or troubleshooting the unit.
Service Mode can be accessed by holding ► and ▼ buttons
simultaneously for 5 seconds.
In Service Mode, the unit will operate with the diverter valve
in the space heating position; therefore, zone(s) in the heating
system must be actively running in order to reject the heat
generated.
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Start-up
3. Press the ► and ▼ buttons (simultaneously) for 5
seconds to enter Service Mode.
4. Insert the probe from a combustion analyzer into the hole
on the vent adapter.
5. Once the boiler has modulated up to full fire, measure the
combustion. The values should be in the range listed in
Table 10A below. The CO levels should be less than 150
ppm for a properly installed unit.
If the combustion is not within the specified range,
reference Section 13 - Troubleshooting for possible causes
and corrective actions.
Table 10A Flue Products Chart
Natural Gas
Goal
Range
CO2
O2
Propane
CO2
O2
8.5% - 10.5% 2.3% - 5.7% 10.0% - 11% 4.1% - 5.6%
Target
9.0%
4.9%
10.5%
4.9%
6.
Once the combustion analysis is complete, exit Service
Mode.
7.
Turn the main power off to the boiler and replace the
plug into the vent adapter.
8.
Place the boiler back into normal operation.
WARNING
You must replace the flue gas temperature
sensor to prevent flue gas spillage into the
room. Failure to comply could result in
severe personal injury, death, or substantial
property damage.
Set space heating operation
Determine controlling sensor
For space heating systems, the temperature control can be
based on the outlet or the system supply sensor (optional). The
control will automatically switch to the system supply sensor
once it is connected.
Verify space heat circulator operation
The Space Heating Mode controls the boiler pump and the
diverter valve. When the boiler control receives a space
heating call for heat and the boiler is not heating a DHW
(Domestic Hot Water) call, and the set point is not met, it
turns on the boiler pump and places the diverter valve in the
space heating position. After the space heating call for heat
ends, the boiler pump continues to run for a short period of
time. This pump delay is factory set to 30 seconds. After this
pump delay, the pump is turned off and the diverter valve is
placed into the DHW position.
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Set domestic hot water (DHW) operation
Verify DHW operation
The DHW Heating Mode controls the boiler pump and
the diverter valve. When the boiler control receives a
DHW call for heat from the DHW flow switch, it turns on
the boiler pump and puts the diverter valve in the DHW
position to route boiler water through the brazed plate heat
exchanger. During the call, the boiler control will modulate
to maintain the DHW outlet temperature to the DHW set
point.
After the DHW call for heat ends, the boiler pump
continues to run for a short period of time. This pump
delay is factory set to 30 seconds.
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Operating information
General
Parameters in the set points menu:
How the boiler operates
-
The Noble Combi Boiler uses an advanced stainless steel heat
exchanger and electronic control module that allows fully
condensing operation. The blower pulls in air and pushes
flue products out of the boiler through the heat exchanger
and flue piping. The control module regulates blower speed
to control the boiler firing rate. The gas valve senses the
amount of air flowing into the boiler and allows only the right
amount of gas to flow.
-
How the control module operates
The boiler control module receives inputs from boiler sensors
and external devices. The control module activates and
controls the blower and gas valve to regulate heat input.
Switches the boiler pump on and off and controls the
diverter valve as needed. The user programs the module to
meet system needs by adjusting control parameters. These
parameters set operating temperatures and boiler operating
modes. Boiler operation can be based on boiler outlet water
temperature or system supply temperature.
-
-
Menus
CAUTION
Before changing parameters, note the
settings so that the unit can be returned
to its original operating parameters.
NOTICE
Parameters will be automatically saved
after menu timeout.
Set points menu (user access)
The Set Points Menu can be accessed by pressing the
button.
◄
Figure 11-1 Set Point Menu
-
SH SETPT (COLD DAY)
• Space heating water set point temperature, or the
space heating water set point temperature when
outdoor temperature is at the cold day setting if
outdoor reset is used.
• Range: 68°F – MAX SH SETPT
• Default: 125°F
DHW SETPT
• This is the desired set point temperature of domestic
hot water generated by the unit. Note that the required
anti-scald mixing valve will likely require a setting
greater than the desired domestic hot water
temperature.
• Range: 60°F – MAX DHW SETPT
• Default: 120°F
TEMPERATURE UNITS
• This parameter can be used to select temperature units
to be displayed on the screen (°F/°C)
AUTO RESET HI LIMIT
• When the outlet temperature exceeds the Automatic
Reset High Limit setting, automatic high limit action
occurs. The boiler shuts down until the outlet water
temperature cools below 10°F under this setting and
a 60 second timer has elapsed. Note that this setting
applies to both SH and DHW Modes.
• Range: 32°F – 200°F
• Default: 200°F
MAN. RESET HI LIMIT
• If the outlet temperature continues to increase after
automatic reset high limit action, the Manual Reset
High Limit action occurs when the outlet water
temperature exceeds this setting. This will require
a manual reset before operation can resume. Note that
this setting applies to both SH and DHW Modes.
• Range: 32°F – 210°F
• Default: 210°F
Installer menu (installer only access)
The Installer Menu can be accessed by pressing the ► button
and then entering the installer password.
Figure 11-2 Installer Menu
Button functions in the set points menu
▲/▼ - Change value of current parameter.
►
- Move to the next parameter.
◄
- Save changes and exit the menu.
To exit the menu without saving changes, you must cycle
power to the unit before exiting the menu.
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Operating information
Enter the installer password
Parameters in the installer menu:
To enter the installer password, use the ▲ and ▼ buttons to
change the value of the first digit to 5, then press ► to move
to the next digit. Repeat this process to fill in the remaining
digits and enter the password 5-3-0-9. Once the final digit has
been entered, press the ► button to access the installer menu.
-
Entering the installer password will allow future access to the
installer menu without requiring the password for up to an
hour after the last button is pressed.
-
Installer main menu
-
The Installer Menu is arranged in a menu/sub-menu structure
to help with navigation to the desired settings. The installer
main menu gives a list of available sub-menus.
Figure 11-3 Installer Main Menu
-
Button functions in the installer main menu
▲/▼
►
◄
- Move the cursor through the list of available submenus.
- Access the currently selected sub-menu.
- Save changes and exit the menu.
To exit the menu without saving changes, you must cycle
power to the unit before exiting the menu.
Button functions in the installer sub-menus
▲/▼
►
◄
- Change value of current parameter.
- Move to next parameter or return to main menu
on last parameter in the sub-menu.
- Return to Main Menu or save all changes and return
to Home Screen on the last parameter in the submenu.
To exit the menu without saving changes, you must cycle
power to the unit before exiting the menu.
Note: Certain settings in the Installer Menu can be accessed
in multiple sub-menus for ease of navigation. The Installer
Menu also contains settings that can also be found in the Set
Points Menu to allow full programming of the boiler within
the Installer Menu.
62
GENERAL Submenu
MAX SH SETPT – also found in OUTDOOR RESET
Sub-menu
• Default: 185°F
• Minimum: 60°F
• Maximum: 190°F
MAX DHW SETPT
• Default: 150°F
• Minimum: 60°F
• Maximum: 190°F
AUTO RESET HI LIMIT – also found in Set Points
Menu
• Default: 200°F
• Minimum: 32°F
• Maximum: 200°F
MAN. RESET HI LIMIT – also found in Set Points
Menu
• Default: 210°F
• Minimum: 32°F
• Maximum: 210°F
SH MAX RATE LIMITING
• Default: 100%
• Minimum: 10%
• Maximum: 100%
OUTDOOR RESET Sub-menu
SH SETPT (COLD DAY) – also found in Set Points
Menu
• Default: 125°F
• Minimum: 68°F
• Maximum: MAX SH SETPT
OUTDOOR TEMP COLDEST
• Default: 10°F
• Minimum: -40°F
• Maximum: 75°F
WARM WEATHER SHUTDOWN
• Default: 70°F
• Minimum: 32°F
• Maximum: 104°F
SHIFT RESET
• Default: 0°F
• Minimum: -18°F
• Maximum: 18°F
OUTDOOR TEMP – WARM
• Default: 75°F
• Minimum: 10°F
• Maximum: 104°F
SH SETPT (WARM DAY)
• Default: 75°F
• Minimum: 68°F
• Maximum: 190°F
TIME/DATE Sub-menu
FAULT LOG
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-
-
-
-
Operating information
Installation & Service Manual
(continued)
SETPOINTS Sub-menu – Set Points Menu duplicate
SH SETPT
• Default: 125°F
• Minimum: 68°F
• Maximum: MAX SH SETPT
DHW SETPT
• Default: 120°F
• Minimum: 60°F
• Maximum: MAX DHW SETPT
TEMPERATURE UNITS
• Default: °F
CASCADE Sub-menu
CASCADE ADDRESS
CASCADE TYPE – only available if address is 0
• Boiler size settings – only available if address is 0
ADVANCED COMBI Sub-menu
DHW RESPOND TIME
• Default: 2 minutes
• Minimum: 0 minutes
• Maximum: 15 minutes
PRE-HEAT – (ENABLED/DISABLED)
• Default: ENABLED
DHW BLW WATER TEMP
• Default: 180°F
• Minimum: 68°F
• Maximum: 190°F
DHW OPERATING MODE
• Default: NORMAL
SET-UP WIZARD – Access Set-up Wizard after it has been
completed.
Control inputs and outputs
Room thermostat
The room thermostat input tells the boiler to provide heat for space
heating.
DHW Priority
If a DHW call for heat is received while a Space Heating call is in
progress, the control will start operating in DHW Mode to move
the diverter valve to the DHW position. The control will not
resume Space Heating operation until the DHW call has ended.
Anti-cycling
After the burner turns off, the control will delay the next burner
cycle for a set time period. The time delay will be bypassed if the
inlet water temperature drops too far during the delay. The anticycling delay does not apply to DHW calls for heat.
Modulation
The Noble Combi Boiler is capable of modulating its firing rate
from a minimum of 10% to a maximum of 100%. The firing rate
is dictated by the call for heat (i.e., space heating or domestic hot
water), the heating load, and various other temperature limitations.
Boiler outlet temperature sensor
The Noble Combi Boiler is factory equipped with a boiler outlet
temperature sensor which is also used as the limit sensor for the
heater. During a space heat call for heat, the outlet temperature
sensor is used to control modulation of the boiler unless a system
supply sensor is field installed.
System supply temperature sensor (optional)
An optional factory supplied and field installed system supply
temperature sensor may be used with the Noble Combi Boiler.
When installed, this sensor is used to control modulation of the
boiler during a space heat call for heating.
Boiler inlet temperature sensor
The Noble Combi Boiler is factory equipped with a boiler inlet
temperature sensor.
Combi DHW outlet temperature sensor
The Noble Combi Boiler is factory equipped with a combi
DHW outlet temperature sensor. This sensor is used to control
modulation of the boiler during a DHW call for heat. When
this sensor is missing, limited operation in DHW Mode is
possible by controlling the boiler outlet temperature to the
DHW set point.
DHW flow switch
The Noble Combi Boiler is factory equipped with a DHW flow
switch connected to the control that detects the presence of
DHW water flow rates greater than 0.32 gpm. This input tells
the boiler to provide heat for DHW heating.
Combi diverter valve
The Noble Combi Boiler is factory equipped with a diverter
valve used to route boiler water to the heating system when
in the Space Heating Mode or through the brazed plate heat
exchanger when in DHW Mode. This diverter valve is normally
in the DHW position, thus isolating the boiler from flow in the
heating system.
Boiler pump control
The Noble Combi Boiler is factory shipped with an internal
boiler pump used to generate flow for both space heating and
DHW operation. The boiler pump will run whenever the
burner is firing. The boiler pump will also run during Freeze
Protection and Combi Pre-Heat Modes. The boiler pump will
continue to run for a short time after the burner turns off, the
Freeze Protection Mode ends, or the Combi Pre-Heat Mode
ends.
System pump control
The Noble Combi Boiler is capable of controlling a field
supplied and installed space heating system pump. The system
pump will run whenever there is a space heating call for heat, or
the boiler goes into Freeze Protection Mode. The system pump
will continue to run for a short time after the end of the heat
demand or the Freeze Protection Mode.
Gradient limiting
If during operation of the boiler the outlet water temperature is
rising too quickly, the control will reduce the firing rate to its
lowest setting.
SH rate limiting
The Noble Combi Boiler includes an SH Rate Limiting feature
that limits the maximum modulation during a space heating
call.
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Operating information
Outdoor air reset
Outdoor Air Shutdown
The Noble Combi Boiler uses an advanced non-linear
outdoor reset curve to improve system efficiency by reducing
the boiler water set point as the outdoor temperature warms
up. The installer can set the reset curve by setting both the
SH SETPT (COLD DAY) parameter to the water temperature
required for the coldest design day outdoor temperature and
the COLDEST OUTDOOR TEMP parameter to the coldest
design day outdoor temperature. The installer should limit
the maximum set point for the system using the MAX SH
SETPT parameter. The user can adjust the SH SETPT (COLD
DAY) parameter up to the MAX SH SETPT as needed to
modify the reset curve. For advanced configuration, the
installer can also adjust the warm day point on the curve
using the installer menu, however because of the non-linear
curve, these settings typically do not need to be adjusted.
Outdoor air shutdown specifies the outdoor air temperature at
which the Space Heating demand is blocked. DHW demands
will still be active. Space heating operation will resume once the
outdoor temperature falls below 10°F less than the Outdoor Air
Shutdown setting.
With the outdoor air sensor connected, the control module
will calculate the space heating demand water set point based
on the programmed reset curve to automatically match the
required heat load. For advanced configuration, the installer
can also adjust the warm day point from the Installer Menu,
however because of the non-linear curve, these settings
typically do not need to be adjusted.
Space Heat Rate Limiting
Space Heat Rate Limiting can be used when the maximum
required space heating load is lower than the maximum input
rate of the unit. This feature limits the maximum input rate
during a space heating demand to help keep the unit running
at lower input rates. Space Heat Rate Limiting does not affect
DHW operation.
Flame current support
To prevent nuisance shutdowns when the boiler is firing at low
rates, the control will increase the firing rate when the flame
signal drops too low.
Figure 11-4 Outdoor Reset Curve
MAX SH SETPT
(DEFAULT = 185°F)
CURVE MAY BE LIMITED TO A
LOWER SET POINT
WATER
TEMPERATURE
SET POINT
SH SETPT (COLD DAY)
(DEFAULT = 125°F)
USER ADJUSTABLE
SH SETPT (WARM DAY)
(DEFAULT = 75°F)
NOT TYPICALLY ADJUSTED
OUTDOOR
TEMP (COLDEST)
(DEFAULT = 10°F)
WARM WEATHER
SHUTDOWN
(DEFAULT = 70°F)
OUTDOOR TEMP OUTDOOR RESET CURVE
WARM
WILL BE AUTOMATICALLY LIMITED
(DEFAULT = 75°F)
AT 15°F BELOW COLD DAY NOT
TYPICALLY ADJUSTED
OUTDOOR TEMPERATURE
Combi Pre-Heat
DHW Respond
The Noble Combi Boiler includes an optional Pre-Heat feature
which is intended to maintain the boiler water temperature
within a pre-defined range to improve the time it takes for the
unit to supply heated DHW water. The Pre-Heat feature can
also be used to satisfy low flow DHW demands or for heating
water during DHW recirculation where flows through the
unit may be less than the setting of the flow switch. The PreHeat feature will first try to satisfy these demands using the
integral boiler pump before firing. Pre-heat operation will be
indicated on the display by a flashing DHW icon. When the
unit fires for a Pre-Heat demand, it will immediately ramp to
low fire. Pre-Heat demands will only occur when no other
heating demand is present.
The Noble Combi Boiler includes a DHW respond feature to help
eliminate cold water sandwich issues associated with repeated
DHW demands. After any DHW demand, the unit will go
into pre-purge for a pre-determined time after post-purge has
ended. If a new demand occurs during this DHW respond time,
the unit will be able to immediately enter ignition, reducing the
time it takes for the unit to respond to the subsequent demand.
DHW respond time can be set by the installer for a duration of 0
minutes (disabled) up to 15 minutes.
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Operating information
Cascade
When multiple Noble Combi Boilers are installed, they can
be wired together in a Cascade sequence. A maximum of
eight (8) boilers can be controlled from a single control.
In this application one boiler would be designated as the
Leader control and all others would be designated as Member
controls. The Leader control can be programmed to use
Lead/Lag or Efficiency Optimization control methods. Noble
Combi Boilers can only control Space Heating demands. A
Noble Combi Boiler in a Cascade must have its own DHW
circuit, as DHW will be controlled individually.
Once the Leader receives a call for heat from a room
thermostat, the control will determine what the set point will
be. If outdoor air reset is desired, connect the outdoor air
sensor to the terminals on the Low Voltage Connection Board
on the Leader boiler. The set point will be calculated based
on the programmed reset curve of the Leader. If the water
temperature at the system supply sensor is less than the set
point – 10°F, then the control will initiate a call for heat on
the Cascade.
When a Noble Combi Boiler in a Cascade receives a DHW call
for heat, it will be taken out of the Cascade to satisfy its own
DHW demand. Once its DHW demand has ended, it will be
put back into the Cascade.
To equalize the run time of all boilers on the Cascade, the
firing sequence will automatically be changed at set intervals.
Protection features
Outlet temperature, flue
temperature rise limiting
temperature,
and
The outlet temperature is monitored by the boiler outlet
temperature sensor. When the outlet temperature exceeds
185°F, the unit will reduce the maximum fan speed. If the
outlet water temperature exceeds 195°F the control will shut
the unit down until it cools off.
The control module monitors the flue temperature by a
sensor located in the flue exhaust. If the flue temperature
exceeds 215°F the control will reduce the maximum fan
speed. If the flue temperature exceeds 240°F the control will
shut the unit down. The unit will restart automatically once
the flue temperature drops 25°F and the minimum off time
has expired.
The control module monitors the change in the temperature
after the burner fires to ensure that the flue sensor is properly
installed. In the event that the control module does not detect
the required change in the temperature, modulation will be
limited to 50% or less. Once the required flue temperature
change is observed, the boiler will be allowed to modulate
above 50% on the next call for heat or after the ● (RESET)
button is pressed.
(continued)
The control monitors the temperature difference between the
inlet and the outlet sensor. If this difference exceeds 55°F the
control will reduce the maximum fan speed. If the temperature
difference exceeds 60°F the control will shut the unit down. The
unit will restart automatically once the temperature difference
has dropped below 55°F and the minimum off time has expired.
Freeze protection
DO NOT install the boiler in a room likely to freeze.
The following integral feature of the boiler control module
provides some protection for the boiler only -- not for the
system.
The boiler control module provides freeze-up protection as
follows:
•
•
•
Below an inlet temperature of 45°F, the boiler pump
operates constantly.
Below an inlet temperature of 37°F, the burner fires.
Boiler and pumps turn off if boiler water inlet
temperature rises above 45°F.
NOTICE
CAUTION
When system return temperatures
are maintained below the dew point,
condensation will form on the inside of the
boiler jacket causing some internal sheet
metal components to rust.
This feature of the boiler control module
does not eliminate the possibility of freezing.
The installation must still use recognized
design, installation and maintenance
practice to prevent freeze potential for the
boiler and system.
Low voltage blocking
The blower and gas valve require a minimum amount of
voltage in order to operate properly. If an ignition attempt is
made when the line voltage is temporarily low (such as during a
brownout), the control could enter a manual reset lockout. To
prevent this, the control monitors the voltage and blocks any
heat demands until the voltage returns to an acceptable level.
Monitor external limits
Connections are provided on the connection board for external
limits such as a flow switch or low water cutoff and AUX limit.
The boiler control will shut off the burner and inhibit relighting
whenever any of these external limits open.
Error logging
The control will hold the last 10 lockouts in memory. The date
and time of the occurrence will be recorded as well. Only the 10
most current occurrences will be held in memory.
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Operating information
Space heat temperature regulation
Operating temperature (target)
The boiler control module senses water temperature and
regulates boiler firing rate to achieve a target temperature.
The target temperature is calculated as described in this
section under "Outdoor Reset Operation" when the outdoor
sensor is connected. The maximum target temperature
can be limited by the installer using the MAX SH SETPT.
This temperature can be set between 32°F and 190°F. If the
outdoor sensor is shorted or not properly installed, the target
temperature is fixed at the SH SETPT (Cold Day).
High limit operations
The Noble Combi Boiler is equipped with an adjustable
automatic reset high limit and a manual reset high limit. The
automatic reset high limit has a maximum set point of 200°F
and the manual reset high limit has a maximum set point of
210°F.
Low water cutoff protection
1.
2.
The boiler control module uses temperature sensing of
both supply and return ports of the heat exchanger. If the
flow rate is too low or the outlet temperature too high,
the control module modulates and shuts the boiler down.
This ensures boiler shutdown in the event of low water or
low flow conditions.
Some codes and jurisdiction may accept these integral
features of the control in lieu of requiring an additional
limit control or low water cutoff. Consult local
jurisdiction to determine. A low water cutoff is available
from the factory (100173646).
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Installation & Service Manual
Sequence of operation
The cold domestic water enters the plate heat exchanger through
the DHW inlet connection, flow switch, and strainer. Cold
water flows through the plate heat exchanger, where it is heated
by hot boiler water, and then discharged through the Domestic
Hot Water (DHW) outlet connection.
Heated boiler water is supplied from the primary combustion
heat exchanger through the diverter valve into the plate heat
exchanger. The boiler water heats the colder domestic water,
and is then returned to the primary heat exchanger through the
pump.
While operating in DHW Mode, the diverter valve prevents
water from flowing through the boiler outlet connection to
the heating system. Boiler water is circulated inside the unit
between the plate heat exchanger and the primary combustion
heat exchanger.
The diverter valve is normally in the DHW position when the
unit is in Standby, thus isolating boiler water from flowing to the
heating system. When there is a space heating call, the diverter
valve will move to the space heat position allowing boiler water
to flow from the primary combustion heat exchanger through
the boiler outlet connection to the heating system, bypassing
the plate heat exchanger. The internal pump is used to circulate
water in both Space Heating and DHW Modes.
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Operating information
Installation & Service Manual
(continued)
OPERATION
DISPLAY
1. Upon a call for heat, the control turns on the appropriate pumps.
The flow switch and/or LWCO must close.
2. Once the LWCO has closed, the auxiliary limit switch must
close.
3. The control starts the pre-purge cycle by initiating the blower.
4. The control starts the trial for ignition by firing the spark
electrode and opening the gas valve.
5. If flame is not detected after the sparking ends, the control will
perform a postpurge, then start another prepurge cycle and try
to light the burner again. The control will perform a total of 4
attempts before locking out.
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Operating information
OPERATION
6. If flame is detected, it holds the firing rate steady for a few
seconds to let the flame stabilize, then it begins to modulate the
firing rate based on a set point or some other command.
7. If the space heating call for heat is active and the combi flow
switch starts a DHW call for heat, the diverter valve will move to
the DHW position and the boiler will switch to the DHW Mode.
This will divert the boiler's outlet water from the heating system to
the brazed plate heat exchanger. The control will then modulate
to maintain the DHW outlet temperature at the DHW set point.
8.
Once all calls for heat are satisfied, the control will turn off
the burner. The blower will continue to run during the postpurge
period.
9. Any pumps that are running will continue to run for their
respective pump delay times before turning off. A 60 second
anti-cycle period will start, which will delay any new space
heating call for heat until it times out.
10. In Standby, ready to start a new cycle.
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Maintenance
Maintenance and annual startup
Table 12A Service and Maintenance Schedules
Owner maintenance
Service technician
(see the following pages for instructions)
(see the Noble Combi Boiler User’s Information
Manual for instructions)
General:
• Address reported problems
• Inspect interior; clean and vacuum if
necessary;
• Clean condensate trap
• Check boiler area
Daily
• Check pressure/temperature
gauge
• Check for leaks (water, gas, flue,
condensate)
ANNUAL START-UP
• Verify flue and air lines in good condition
and sealed tight
• Check vent piping
• Check system water pressure/system
piping/expansion tank
• Check air piping
• Check fill water meter
• Test boiler water. When test indicates,
clean system water with approved
system restorer following manufacturer’s
information.
• Check control settings
Monthly
• Check relief valve
• Check condensate drain system
• Check ignition electrodes (sand off any
deposits; clean and reposition)
• Check air vents
• Check wiring and connections
• Perform start-up checkout and
performance verification per Section 10
of this manual.
• Check air and vent termination
screens
Periodically
• Test low water cutoff (if used)
• Reset button (low water cutoff)
• Flame inspection (stable, uniform)
• Flame signal (at least 10 microamps at
high fire)
• Clean the heat exchanger if flue
temperature is more than 54°F above
return water temperature.
Every
6 months
• Check boiler piping (gas and
water) for leaks
• Operate relief valve
• Inspect and clean the flow switch filter
and sanitary bypass filter in the Combi
waterset.
If combustion or performance
indicate need:
• Clean heat exchanger
• Remove and clean
compressed air only
burner
End
of season
months
• Shut boiler down (unless boiler
used for domestic hot water)
using
69
™
FIRE TUBE COMBI
12
Installation & Service Manual
Maintenance
WARNING
Follow the Service and maintenance procedures given throughout this manual and in component literature
shipped with the boiler. Failure to perform the service and maintenance could result in damage to the boiler
or system. Failure to follow the directions in this manual and component literature could result in severe
personal injury, death, or substantial property damage.
WARNING
The boiler should be inspected annually only by a qualified service technician. In addition, the maintenance
and care of the boiler designated in Table 12A and explained on the following pages must be performed to
assure maximum boiler efficiency and reliability. Failure to service and maintain the boiler and system could
result in equipment failure.
WARNING
Electrical shock hazard – Turn off power to the boiler before any service operation on the boiler except as
noted otherwise in this instruction manual. Failure to turn off electrical power could result in electrical shock,
causing severe personal injury or death.
Address reported problems
Check all piping for leaks
1. Inspect any problems reported by the owner and correct
before proceeding.
Eliminate all system or boiler leaks.
Continual fresh makeup water will reduce
boiler life. Minerals can build up in tubes,
reducing heat transfer, overheating heat
exchanger, and causing heat exchanger
failure. Leaking water may also cause
severe property damage.
1. Inspect all water and gas piping and verify to be leak free.
Inspect boiler area
1. Verify that boiler area is free of any combustible materials,
gasoline and other flammable vapors and liquids.
2. Verify that air intake area is free of any of the contaminants
listed in Section 1 of this manual. If any of these are
present in the boiler intake air vicinity, they must be
removed. If they cannot be removed, reinstall the air and
vent lines per this manual.
Inspect boiler interior
1. Remove the front access cover and inspect the interior of
the boiler.
WARNING
2. Look for signs of leaking lines and correct any problems
found.
3. Check gas line using the procedure found in Section 7 Gas Connections.
Flue vent system and air piping
1.
2. Vacuum any sediment from inside the boiler and
components. Remove any obstructions.
Clean condensate trap
2.
1. Remove the clean out cap on the bottom of the trap. Let
the condensate and any debris drain out.
2. Replace the clean out cap and resume operation.
Figure 12-1 Condensate Trap
Verify that boiler vent discharge and air intake are clean
and free of obstructions.
WARNING Failure to inspect for the above conditions
and have them repaired can result in severe
personal injury or death.
Check water system
1. Verify all system components are correctly installed and
operational.
HOSE BARB
2. Check the cold fill pressure for the system. Verify it is
correct (must be a minimum of 12 psi).
MOUNTING NUT
3. Watch the system pressure as the boiler heats up (during
testing) to ensure pressure does not rise too high.
Excessive pressure rise indicates expansion tank sizing or
performance problem.
FLOAT BALL
CONDENSATE
DRAIN
REMOVABLE CAP
TO CLEAN OUT TRAP
DIR #2000529332 00
70
Visually inspect the entire flue gas venting system and air
piping for blockage, deterioration or leakage. Repair any
joints that show signs of leakage. Verify that air inlet pipe
is connected and properly sealed.
4. Inspect air vents and air separators. Remove air vent caps
and briefly press push valve to flush vent. Replace caps.
Make sure vents do not leak. Replace any leaking vents.
Check expansion tank
1. Expansion tanks provide space for water to move in
and out as the heating system water expands due to
temperature increase or contracts as the water cools. Tanks
may be open, closed or diaphragm or bladder type. See
Section 6 - Hydronic Piping for suggested best location of
expansion tanks and air eliminators.
™
FIRE TUBE COMBI
12
Maintenance
Installation & Service Manual
(continued)
Check fill water meter
1. Check fill water meter for water usage. If the amount
exceeds 5% of your system volume, you could have a leak.
Have the system checked for leaks and fixed by a qualified
service technician.
Test boiler water
1. Test boiler water. Reference the Noble Installation and
Operation Manual for guidelines. When test indicates,
clean system water with approved system restorer
following the manufacturer’s information.
Check boiler relief valve
1.
Inspect the relief valve and lift the lever to verify flow.
Before operating any relief valve, ensure that it is piped
with its discharge in a safe area to avoid severe scald
potential. Read Section 6 - Hydronic Piping before
proceeding further.
Following installation, the valve lever
WARNING must be operated AT LEAST ONCE
A YEAR to ensure that waterways
are clear. Certain naturally occurring
mineral deposits may adhere to the valve,
rendering it inoperative. When manually
operating the lever, water will discharge
and precautions must be taken to avoid
contact with hot water and to avoid water
damage. Before operating lever, check
to see that a discharge line is connected
to this valve directing the flow of hot
water from the valve to a proper place
of disposal. Otherwise severe personal
injury may result. If no water flows, valve
is inoperative. Shut down the boiler until
a new relief valve has been installed.
Safety relief valves should be re-inspected
WARNING AT LEAST ONCE EVERY THREE
YEARS, by a licensed plumbing contractor
or authorized inspection agency, to ensure
that the product has not been affected
by corrosive water conditions and to
ensure that the valve and discharge line
have not been altered or tampered with
illegally. Certain naturally occurring
conditions may corrode the valve or its
components over time, rendering the
valve inoperative. Such conditions are
not detectable unless the valve and its
components are physically removed and
inspected. This inspection must only
be conducted by a plumbing contractor
or authorized inspection agency – not
by the owner. Failure to re-inspect the
boiler relief valve as directed could result
in unsafe pressure buildup, which can
result in severe personal injury, death, or
substantial property damage.
2. After following the warning directions in this manual, if
the relief valve weeps or will not seat properly, replace the
relief valve. Ensure that the reason for relief valve weeping
is the valve and not over-pressurization of the system due
to expansion tank waterlogging or undersizing.
Inspect ignition
electrodes
/
flame
sense
1. Remove the ignition / flame sense electrode from the boiler
heat exchanger access cover.
2. Remove any deposits accumulated on the ignition/flame
sense electrode using sandpaper. If the electrode cannot
be cleaned satisfactorily, replace the ignition/flame sense
electrode with a new one.
3. Replace ignition/flame sense electrode, making sure gasket
is in good condition and correctly positioned.
Check ignition ground wiring
1. Inspect boiler ground wire from the heat exchanger access
cover to ground terminal strip.
2. Verify all wiring is in good condition and securely attached.
3. Check ground continuity of wiring using continuity meter.
4. Replace ground wires if ground continuity is not satisfactory.
Check all boiler wiring
1. Inspect all boiler wiring, making sure wires are in good
condition and securely attached.
Check control settings
1. Set the boiler control module display to Parameter Mode and
check all settings. Adjust settings if necessary. See Section
11 - Operating Information for adjustment procedures.
2. Check settings of external limit controls (if any) and adjust
if necessary.
Perform start-up and checks
1.
Start boiler and perform checks and tests specified in
Section 10 - Start-up.
2.
Verify cold fill pressure is correct and that operating
pressure does not go too high.
Check burner flame
1.
Inspect flame through observation window.
2.
If the flame is unsatisfactory at either high fire or low fire,
turn off boiler and allow boiler to cool down. Remove the
burner and clean it thoroughly using a vacuum cleaner or
compressed air. Do not use compressed air to clean burner
if performed inside a building.
3.
Remove the burner, reference FIG. 12-2 (page 72).
4.
When replacing the burner, ensure gasket is in good
condition and positioned correctly (FIG. 12-2).
71
™
FIRE TUBE COMBI
12
Installation & Service Manual
Maintenance
Handling ceramic fiber materials
Figure 12-2 Burner Assembly
REMOVAL OF COMBUSTION CHAMBER
LINING
TOP PLATE
WARNING
GASKET
BURNER
DIR #2000534736 00
Check flame signal
1. At high fire the flame signal shown on the display should
be at least 10 microamps.
2. A lower flame signal may indicate a fouled or damaged
ignition / flame sense electrode. If cleaning the ignition/
flame sense electrode does not improve, ground wiring is
in good condition, and ground continuity is satisfactory,
replace the ignition / flame sense electrode.
3. See Section 13 - Troubleshooting for other procedures to
deal with low flame signal.
Review with owner
1. Review the Noble Combi Boiler User’s Information
Manual with the owner.
2. Emphasize the need to perform the maintenance schedule
specified in the Noble Combi Boiler User’s Information
Manual (and in this manual as well).
3. Remind the owner of the need to call a licensed contractor
should the boiler or system exhibit any unusual behavior.
4. Remind the owner to follow the proper shutdown
procedure and to schedule an annual start-up at the
beginning of the next heating season.
72
The combustion chamber insulation in
this appliance contains ceramic fiber
material. Ceramic fibers can be converted
to cristobalite in very high temperature applications. The
International Agency for Research on Cancer (IARC) has
concluded, “Crystalline silica inhaled in the form of quartz
or cristobalite from occupational sources is carcinogenic to
humans (Group 1).” Normal operating temperatures in this
appliance are below the level to convert ceramic fibers to
cristobalite. Abnormal operating conditions would have to
be created to convert the ceramic fibers in this appliance to
cristobalite.
The ceramic fiber material used in this appliance is an irritant;
when handling or replacing the ceramic materials it is advisable
that the installer follow these safety guidelines.

Avoid breathing dust and contact with skin and eyes.
• Use NIOSH certified dust respirator (N95). This type of
respirator is based on the OSHA requirements for cristobalite
at the time this document was written. Other types of
respirators may be needed depending on the job site
conditions. Current NIOSH recommendations can be found
on the NIOSH website at http://www.cdc.gov/niosh/homepage.html.
NIOSH approved respirators, manufacturers, and phone
numbers are also listed on this website.
• Wear long-sleeved, loose fitting clothing, gloves, and eye
protection.

Apply enough water to the combustion chamber lining to
prevent airborne dust.
 Remove the combustion chamber lining from the appliance
and place it in a plastic bag for disposal.
 Wash potentially contaminated clothes separately from
other clothing. Rinse clothes washer thoroughly.
NIOSH stated First Aid.
 Eye: Irrigate immediately.
 Breathing: Fresh air.
™
FIRE TUBE COMBI
12
Maintenance
Installation & Service Manual
(continued)
Cleaning the boiler heat exchanger
1. Shut down boiler:
• Follow the “To Turn Off Gas to Appliance” instructions
for the boiler in Section 10 - Startup of the Lochinvar
Combi Boiler Installation and Operation Manual.
• Do not drain the boiler unless it will be exposed to
freezing temperatures. If using freeze prevention fluid
in system, do not drain.
2. Allow time for the boiler to cool to room temperature if
it has been firing.
3. Remove the front access panel.
4. Disconnect the wiring and reference hose from the gas
valve.
5. Disconnect the wiring from the fan assembly.
6. Disconnect the ignition cable and ground wire from the
igniter.
7. Using a 3 mm Allen wrench, remove the four (4) screws
securing the gas valve flange to the gas valve assembly.
8. Using a 5/16" nut driver, loosen the ratchet clamp
connecting the air intake to the venturi.
9. Using a 10 mm wrench, remove the six (6) nuts securing
the heat exchanger top plate to the heat exchanger.
10. Remove the heat exchanger top plate, gas valve, fan and
venturi as one assembly and set aside.
WARNING The boiler contains ceramic fiber
materials. Use care when handling these
materials per instructions on page 72.
Failure to comply could result in severe
personal injury.
11. Remove the condensate trap from the bottom of the heat
exchanger. Place a bucket underneath the condensate
fitting attached to the heat exchanger for drainage.
12. Use a vacuum cleaner to remove any accumulation on the
boiler heating surfaces. Do not use any solvent.
13. Using a clean cloth dampened with warm water, wipe out
the combustion chamber. Do NOT use a metal bristled
brush.
14. Rinse out debris with a low pressure water supply.
15. Allow the heat exchanger to thoroughly dry.
16. Reassemble the unit in reverse order of component removal
and reinstall the condensate trap.
Damaged gaskets and seals in the system
CAUTION can result in substantial property damage.
Ensure that damaged or torn gaskets are
replaced.
17. Perform start-up and check-out procedures in the Check
Flame and Combustion - Section 10 Startup of this
manual.
18. Resume operation.
Cleaning the combi boiler brazed
plate heat exchanger
1. Shut down boiler:
• Follow the “To Turn Off Gas to Appliance” instructions
for the boiler in Section 10 - Startup of the Lochinvar
Combi Boiler Installation and Operation Manual.
• Do not drain the boiler unless it will be exposed to
freezing temperatures. If using freeze prevention fluid
in system, do not drain.
2.
Shut off domestic water supply.
3.
Isolate/disconnect the domestic water piping leading to
the domestic water inlet and outlet.
4.
Flush the brazed plate heat exchanger.
5.
Follow the above steps in reverse order to place the boiler
back into service.
6.
Resume operation.
DHW flow switch filter cleaning
1. Shut down boiler:
• Follow the “To Turn Off Gas to Appliance” instructions
for the boiler in Section 10 - Startup of the Lochinvar
Combi Boiler Installation and Operation Manual.
2. Allow time for the boiler to cool to room temperature if it
has been firing.
3. Remove the front access panel.
4. Locate the flow sensor on the flow switch (as shown in FIG.
12-3 on page 74). Slide the flow sensor off the flow switch.
5.
Using an 18 mm hex/socket wrench, remove the flow switch
assembly from the unit (FIG. 12-3).
6.
Remove the filter from the flow switch and clean by either
blowing water or air into the open end of the filter
as shown in FIG. 12-4.
7.
Clean the O-ring seat and verify that it is not damaged.
Apply a small amount of grease to the flow switch O-ring
seat as shown in FIG. 12-5. Reinstall the filter to the flow
switch. Reinstall the flow switch back into the unit and
torque to 10 - 14 Nm (7.4 - 10.3 ft. lbf).
8.
Place the flow sensor back onto the flow switch.
9.
If cleaning is unsuccessful, replace the flow switch assembly.
10. Reinstall the front access panel removed in Step 3 and
resume operation.
NOTICE
When maintaining the flow switch, it is
also recommended to maintain the bypass
(see page 74 for a detailed description of
cleaning the bypass filter).
73
™
FIRE TUBE COMBI
12
Maintenance
Figure 12-3 Remove flow sensor and flow switch
assembly
Installation & Service Manual
Bypass filter cleaning
1. Shut down boiler:
• Follow the “To Turn Off Gas to Appliance” instructions
for the boiler in Section 10 - Startup of the Lochinvar
Combi Boiler Installation and Operation Manual.
2. Allow time for the boiler to cool to room temperature if it has
been firing.
3. Remove the front access panel.
FLOW SWITCH
ASSEMBLY
DIR #2000536540 00
4. Use a 16 mm 5/8" wrench to unscrew and remove the bypass
assembly (see FIG. 12-6). If needed, use water to clean the
metallic filter.
5.
Reinstall the bypass assembly. Torque the bypass to 7 - 10 Nm
(5.2 - 7.4 ft. lbf).
6.
If cleaning is unsuccessfuly, replace the bypass assembly.
7.
Reinstall the front access panel removed in Step 3 and
resume operation.
REMOVE FLOW SENSOR
Figure 12-6 Remove bypass assembly
Figure 12-4 Clean flow switch filter
BLOW AIR OR WATER INTO THE OPEN
END OF THE FLOW SWITCH FILTER
DIR #2000542775 00
DIR #2000536591 00
Figure 12-5 Clean O-ring seat
CLEAN O-RING SEAT
DIR #2000542758 00
74
REMOVE BYPASS
ASSEMBLY
™
FIRE TUBE COMBI
12
Installation & Service Manual
Maintenance
Test low water flow conditions
Figure 12-7 Adjust outlet isolation valve
NOTICE
This test is to be carried out once the
Noble Combi Boiler is completely
piped in with adequate gas and water
flow. Once the test is completed,
ensure that the isolation valve is
opened up to allow full water flow.
Test procedure
1. Place the boiler into the active position by pressing the
UP button for five (5) seconds (see page 57).
2. Hold the ► button plus the ▼ button for five (5)
seconds to enter Service Mode, allowing the unit to fire
up to 100% modulation.
3. Allow the unit to progress through its normal
diagnostics and pre-purge programming.
ADJUST OUTLET
ISOLATION VALVE ONLY
4. Allow the unit to fire and operate until the temperatures
stabilize. This occurs when the inlet and outlet
temperatures are rising together and the Delta T (
T) is maintained.
5. When the unit stabilizes, begin to slowly shut off the
isolation valve on the outlet piping of the boiler (see
FIG. 12-7). This will begin to restrict the flow and
simulate a low flow condition.
6.
While slowly shutting off the isolation valve, refer
to the Status Screen to watch the behavior of the
boiler. This screen allows you to monitor the inlet
temperature, outlet temperature, and T.
7.
When the T reaches 55˚F, the control will attempt
to modulate the firing rate down to protect it from low
flow conditions.
8.
When the T reaches 60°F, the control module will
turn off the burner. If the control module shuts down,
the test was successful.
9.
Completely open the isolation valve on the outlet
piping of the boiler.
DIR #2000528875 00
10. Resume operation.
75
Installation & Service Manual
™
FIRE TUBE COMBI
13
Troubleshooting
WARNING
WARNING
Label all wires prior to disconnection
when servicing controls. Wiring
errors can cause improper and
dangerous operation.
Always
disconnect power to the boiler before
servicing. Failure to comply could
result in severe personal injury, death,
or substantial property damage.
Never jumper (bypass) any device
except for momentary testing as
outlined in the Troubleshooting
chart. Severe personal injury, death,
or substantial property damage can
result.
Before troubleshooting:
Check control module fuses
NOTICE
ALWAYS check control module fuses
before replacing control module or any
major components (blower, etc.). If one
of these fuses is blown, it can prevent the
control module or other components from
operating.
1.
Turn OFF the power to the boiler at the external line
switch.
2.
Remove front door/cover.
3.
Remove the control module cover.
4.
Inspect fuses F1, F2, and F3, see FIG 13-1 below.
Figure 13-1 Control Module Fuses
1. Have the following items:
a. Voltmeter that can check 120 vac, 24 vac, and
12 vdc.
b. Continuity checker.
c. Contact thermometer.
2. Check for 120 vac (minimum 102 vac to maximum
132 vac) to boiler.
3. Make sure thermostat is calling for heat and contacts
(including appropriate zone controls) are closed.
Check for 24 vac between thermostat wire nuts and
ground.
4. Make sure all external limit controls are installed
and operating.
Check the following:
1. Wire connectors to control module are securely
plugged in at the module and originating control.
2. Gas pressures:
• Maximum: 14 inches w.c. (natural and LP) with
no flow (lockup) or with boiler on
• Minimum: 4 inches w.c. (natural), 8 inches w.c.
(LP) with gas flowing (verify during boiler
startup)
76
F3 - 0.8 AMP FUSE
24V DC POWER SUPPLY
F1 - 6.3 AMP FUSE
PUMPS
F2 - 3.15 AMP FUSE
BLOWER
IMG00260
5. The boiler is shipped with three (3) spare fuses in a plastic bag
provided with the unit.
6. If necessary, replace open fuse (F3 is .80 amps, F2 is 3.15 amps,
and F1 is 6.3 amps).
Note: Fuses F1, F2 and F3 are all slow blow fuses.
WARNING
Do not jumper fuse or replace with any fuse
except as specified. Failure to comply could
result in severe personal injury, death, or
substantial property damage.
7. Install control module cover and front door/cover after fuse
inspection.
8. Restore power to the boiler at the external line switch and
verify boiler operation (Section 10 - Start-up) after completing
boiler service.
™
FIRE TUBE COMBI
13
Troubleshooting
Installation & Service Manual
(continued)
Checking temperature sensors
The boiler temperature sensors (inlet water, outlet water, system water, flue, and outdoor air) are all resistance type devices. The
following tables show the correct values for the sensors at various temperatures. Use an ohmmeter to read the resistance of the
sensor at a known temperature. If the resistance of the sensor does not closely match its corresponding table, replace the sensor
It is important to note that the flue and outlet water sensors have two temperature sensing devices in one housing. These devices
are designated as S1a/S1b, outlet sensor and S3a/S3b, flue sensor. Please reference the wiring diagram in Section 14 of this
manual for correct terminal location.
Table 13-1A - Inlet Water/System/DHW Sensor
Resistance vs. Temperature
Table 13-1B - Outdoor Air Sensor Resistance vs.
Temperature
Temperature Resistance Temperature Resistance
Temperature Resistance Temperature Resistance
50
18,780
158
1,990
68
12,263
176
1,458
86
8,194
194
1,084
104
5,592
212
817
122
3,893
140
2,760
-50
-40
-30
-20
10
0
10
490,813
336,606
234,196
165,180
118,018
85,362
62,465
20
30
40
50
60
70
80
46,218
34,558
26,099
19,900
15,311
11,883
9,299
Table 13-1C - Outlet Water Sensor Resistance vs. Temperature
S1a
S1b
(Wire Color - R/BK and Y)
(Wire Color - G and Y)
Temperature Resistance Temperature Resistance Temperature Resistance Temperature Resistance
50
68
86
104
122
140
19,553
12,690
8,406
5,715
3,958
2,786
158
176
194
212
2,004
1,464
1,084
816
50
68
86
104
122
140
40,030
25,030
16,090
10,610
7,166
4,943
158
176
194
212
3,478
2,492
1,816
1,344
Table 13-1D - Flue Sensor Resistance vs. Temperature
S3a
S3b
(Wire Color - W/B and Y)
(Wire Color - PR and Y)
Temperature Resistance Temperature Resistance Temperature Resistance Temperature Resistance
50
68
86
104
122
140
40,030
25,030
16,090
10,610
7,166
4,943
158
176
194
212
3,478
2,492
1,816
1,344
50
68
86
104
122
140
258,500
125,500
80,220
52,590
35,270
24,160
158
176
194
212
16,870
12,000
8,674
6,369
77
™
FIRE TUBE COMBI
13
Installation & Service Manual
Troubleshooting
Table 13-2 Troubleshooting Chart - Noisy System
FAULT
CAUSE
CORRECTIVE ACTION
Supply gas problem.
Natural gas • Refer to Section 7 - Gas Connections
pressures should be between 4 inches w.c. detailed information concerning the gas supply.
and 14 inches w.c. LP gas pressures
should be between 8 inches w.c. and
14 inches w.c.
Gas/air mixture problem.
Noisy
Operation
Dirty/damaged burner.
for
• Refer to the Gas Valve Adjustment Procedure on
page 87 of this manual for the proper gas valve setting.
Verify that the vent/air intake lengths do not exceed the
maximum listed in Section 3 - General Venting.
• Refer to page 72 in this manual for the burner removal
and inspection procedure. Clean or replace the burner
door assembly as necessary.
Low water flow through the heat exchanger. • Refer to Section 6A - Hydronic Piping for minimum
flow rates. Verify that the boiler and system pump are
running on a call for heat.
No Pump
Operation Boiler / DHW
Pump
Air in the piping system.
• Properly purge all air from the piping system.
Low system water pressure.
• Verify system pressure is a minimum of 12 psi.
Blown fuse.
• Replace fuse F1 on the control board, see page 76 of
this manual.
Note: Make sure pump amperage does not exceed
1.8 amps.
Faulty pump.
• Replace pump.
Internal fault on control board.
• Replace main control board.
Relief Valve
System
pressure exceeds relief
Opening
setting.
• Lower the system pressure below the 30 psi rating of
the supplied relief valve or replace the standard relief
valve with a higher rated valve up to the maximum
valve
pressure of the heat exchanger.
• Improperly sized expansion tank.
78
™
FIRE TUBE COMBI
13
Troubleshooting
Installation & Service Manual
(continued)
Table 13-3 Troubleshooting Chart - Fault Messages Displayed on Boiler Interface
FAULT
MEMORY
ERROR
DESCRIPTION
The control module has detected parameter
settings that are corrupted.
CORRECTIVE ACTION
• Replace control module.
• Vent/air intake lengths exceed the maximum allowed
lengths. Refer to Section 3 - General Venting for
proper lengths.
FAN SPEED
(will require a manual
reset once the condition
has been corrected. Press
the RESET button on the
display to reset.)
The actual fan RPM is outside of the tolerance
of the fan speed RPM target.
• Check for obstruction or blockage in the vent/air
intake pipes or at terminations.
• Check the wiring connections at the fan and at the
main control board.
• Replace the fan.
• Replace the main control board.
Blown fuse.
• Replace fuse F2 on the control board, see page 76
of this manual.
• Check boiler pump operation on a call for heat.
Flow Switch/
LWCO
• Check for closed valves or obstructions in the boiler
piping.
The low water cutoff (LWCO) is not making.
(will require a manual
reset once condition has
been corrected. Press
the RESET button on the
SMART SYSTEM display
to reset.)
• Verify system is full of water and all air has been
purged from the system.
• Check for a loose or misplaced jumper if flow switch
is not installed.
• Replace LWCO.
Blown fuse.
FLAME
SEQUENCE
(will require a manual The flame detector circuit is seeing a flame
reset once the condition signal when the gas valve is OFF.
has been corrected. Press
the RESET button on the
display to reset.)
• Replace fuse F3 on the control board, see page 76
of this manual.
• Verify flame is not present. If present, turn off gas
supply and replace gas valve.
• Check supply voltage for proper polarity.
• Check external wiring for voltage feedback.
• Check the flame rod and make sure it is clean.
• Check the internal wiring for bad connections.
• Replace main control board.
79
™
FIRE TUBE COMBI
13
Installation & Service Manual
Troubleshooting
Table 13-3 (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Boiler Interface
FAULT
DESCRIPTION
CORRECTIVE ACTION
• Adjust the set point of the auto reset limit to a higher
setting up to a maximum of 200°F. Reference Section
11 - Operating Information for adjusting procedures.
• Verify that the system is full of water and that all air
has been properly purged from the system.
• Verify that the boiler is piped properly into the heating
system.
Refer to Section 6 - Hydronic Piping
for the proper piping methods for the Lochinvar
Combi Boiler.
OUTLET ARHL
• Check 120 vac to boiler pump motor on a call for
heat. If voltage is not present, check wiring back to
the main control board.
The outlet water temperature has exceeded
•
Replace
the main control board if necessary.
the setting of the automatic reset high limit.
• If 120 vac is present on a call for heat and the boiler
pump is not operating, replace the pump.
• If operating on something other than an outlet sensor,
check temperature setting of the main control board.
• If the optional manual reset high limit has tripped,
check setting of the device.
• Check resistance of water sensors and compare to
Table 13-1A on page 77 of this manual. Replace
sensor if necessary.
• Check operation of diverter valve motor. Replace if
necessary.
• Check the wiring connections to switch. Wires should
be connected to the common and normally closed
terminals.
• Air intake lengths exceed the maximum allowed
lengths. Refer to Section 3 - General Venting
for proper lengths.
AIR PRESSURE
SWITCH
(will require a manual
reset once the condition Air pressure switch contacts are open.
has been corrected.
Press the RESET button
on the display to reset.)
• Check for obstruction or blockage in the air
intake pipes or at terminations.
• Check reference hoses connected to the air pressure
switch for blockage or obstruction.
• Inspect the burner. Reference page 72 of this manual
for removal and cleaning procedures. Replace if
necessary.
• Inspect the heat exchanger. Reference page 73 of
this manual for removal and cleaning procedures.
• Faulty air pressure switch. Replace switch.
BLOCKED
DRAIN
Thermal fuse on heat exchanger has opened.
AUX LIMIT
FAULT
Aux limit device open.
80
• Check the wiring connections to the fuse on the heat
exchanger.
• Check continuity across the thermal fuse.
replace heat exchanger.
• Check wiring to aux limit device.
• Check aux limit device.
If open,
™
FIRE TUBE COMBI
13
Troubleshooting
Installation & Service Manual
(continued)
Table 13-3 (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Boiler Interface
FAULT
DESCRIPTION
CORRECTIVE ACTION
• Inspect spark electrode and associated wiring for
damage and connection. Reference page 71 of this
manual for removal and cleaning procedures.
Replace if necessary.
FLAME FAIL:
RUNNING
(will require a manual The unit has lost flame signal four (4) times
reset once the condition during a call for heat.
has been corrected.
Press the RESET button
on the display to reset.)
• Check for proper electrical grounding of the unit.
• Check incoming supply gas pressure. Natural gas
pressures should be between 4 - 14 inches w.c. and
LP gas pressures should be between 8 - 14 inches w.c.
Refer to Section 7 - Gas Connections
for detailed information concerning the gas supply.
• Verify that the plastic hose from the gas valve to the air
inlet is connected and is not damaged.
• Verify that the vent/air intake pipes are correctly
installed and that there are no obstructions.
• Check for 24 vac to the gas valve at the 2-pin
connection on the side of the main control board during
the ignition attempt. If no voltage is present, replace
the main control board.
• If 24 vac is present at the main control board, check
the wiring between the main control board and the gas
valve. Replace the wiring if necessary. Do not
disconnect the wiring from the gas valve and attempt to
measure voltage at that point. The main control board
can detect if the gas valve is not connected and will
display the Gas Valve or Gas Valve Fail fault.
FLAME FAIL:
IGNITION
(will require a manual The unit has failed to prove main burner
reset once the condition ignition after several attempts.
has been corrected.
Press the RESET button
on the display to reset.)
• If 24 vac is present, check the outlet of the valve to
ensure the valve is flowing gas. With a manometer
connected to the outlet tap of the gas valve, when the
unit is in the prepurge period, there should be a
negative pressure present.
When the valve is
energized a change in pressure should occur. If the
pressure change does not occur, the gas valve is not
opening. Replace the gas valve.
• Inspect flame sensor and associated wiring.
Reference page 71 of this manual for removal and
cleaning procedures. Replace if necessary.
• Inspect and clean the heat exchanger as necessary.
Reference page 73 of this manual for cleaning
procedures.
• Inspect the burner. Reference page 72 of this manual
for removal and cleaning procedures. Replace if
necessary.
• Replace the main control board.
81
™
FIRE TUBE COMBI
13
Installation & Service Manual
Troubleshooting
Table 13-3 (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Boiler Interface
FAULT
FLUE TEMP
LIMIT
FLUE TEMP
HIGH
DESCRIPTION
CORRECTIVE ACTION
The stack temperature has exceeded the
Flue Temp Limit set parameters.
• Inspect the heat exchanger. Reference page 71 of
this manual for the procedure on how to clean the flue
side of the heat exchanger.
• Inspect the flue sensor and associated wiring.
Measure the resistance of the flue sensor and
compare to Table 13-1D on page 77 of this manual.
Replace the sensor if necessary.
The stack temperature has exceeded the set
parameters for the boiler.
• Verify that the vent/air intake pipes are properly
installed and that there are no obstructions.
• Replace the main control board.
OUTLET MRHL
• Verify that the system is full of water and that all air
has been properly purged from the system.
(will require a manual
• Verify that the boiler is piped properly into the heating
reset once the condition The outlet water temperature has exceeded
system. Refer to Section 6A - Hydronic Piping
has been corrected.
the setting of the manual reset high limit.
for the proper piping methods for the Lochinvar Combi
Press the RESET button
Boiler.
on the display to reset.)
• Check 120 vac to boiler pump motor on a call for
heat. If voltage is not present, check wiring back to
the main control board.
• Replace the main control board if necessary.
• If 120 vac is present on a call for heat and the boiler
pump is not operating, replace the pump.
OUTLET TEMP Outlet water temperature has exceeded the • If operating on something other than an outlet sensor,
check temperature setting of the main control board.
maximum outlet water temperature.
HIGH
• Check resistance of water sensors and compare to
Table 13-1A on page 77 of this manual. Replace
sensor if necessary.
• Check operation of diverter valve motor. Replace if
necessary.
OUTLET TEMP
DIFF
(will require a manual The temperature difference between the two
reset once the condition (2) outlet sensors is too high.
has been corrected.
Press the RESET button
on the display to reset.)
FLUE SENSOR
FAULT
(will require a manual One or both of the flue sensors is open or
reset once the condition shorted.
has been corrected.
Press the RESET button
on the display to reset.)
82
• Check wiring to sensor.
Make sure wiring is
connected and not damaged. Reconnect / repair
wiring if necessary.
• Measure the resistance of the sensor and compare to
the resistance in Table 13-1C on page 77 of this manual.
Replace sensor if necessary.
• Replace control module.
• Inspect the flue sensor and associated wiring.
Measure the resistance of the flue sensor and
compare to Table 13-1D on page 77 of this manual.
Replace the sensor if necessary.
• Replace the main control board.
™
FIRE TUBE COMBI
13
Troubleshooting
Installation & Service Manual
(continued)
Table 13-3 (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Boiler Interface
FAULT
DESCRIPTION
OUTLET SENSOR
FAULT
(will require a manual
reset once the condition One or both of the outlet sensors has
opened or shorted.
has been corrected.
Press the RESET
button on the display to
reset.)
CORRECTIVE ACTION
• Check the sensor and its associated wiring. Repair or
replace the sensor or wiring if damaged.
• Measure the resistances of the sensors and compare
the resistances to the tables on page 77. Replace if
necessary.
INLET SENSOR
FAULT
(will require a manual
reset once the condition The inlet sensor is open.
has been corrected.
Press the RESET
button on the display to
reset.)
SET POINT MET
ANTI-CYCLING
• Check the sensor and its associated wiring. Repair or
replace the sensor or wiring if damaged.
The temperature has reached the set point • None
+ 10°F.
The main control board has received a call
for heat too quickly after the previous call for
heat has ended.
• The control board will release the call for heat after 60
seconds.
• The control board will release the call for heat if the
outlet temperature drops 10°F.
• Verify that the system is full of water and that all air
has been properly purged from the system.
DELTA T HIGH
• Verify that the boiler is piped properly into the heating
system. Refer to Section 6 - Hydronic Piping
The temperature rise across the heat
for the proper piping methods for the Lochinvar Combi
exchanger has exceeded the set parameters
Boiler.
for the boiler.
• Check for 120 vac to the boiler pump motor on a call
for heat. If voltage is not present, check the wiring
back to the main control board. Replace the main
control board if necessary.
• If 120 vac is present on a call for heat and the boiler
pump is not operating, replace the pump.
The fan speed is being limited due to the
temperature rise across the heat exchanger
exceeding 55°F.
• Verify that the boiler pump is set to the proper speed
or that the pump is the proper size. Reference
Section 6 - Hydronic Piping for boiler
pump specifications.
83
Installation & Service Manual
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FIRE TUBE COMBI
13
Troubleshooting
Table 13-3 (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Boiler Interface
ERROR CODE
DESCRIPTION
CORRECTIVE ACTION
• Check 120 vac supply to the transformer.
LOW VOLTAGE
120 vac input to the main control board has
dropped below 80 vac.
• Check wiring connections at the low voltage
terminal strip.
• Check the wire size/length to remote devices.
• Replace the transformer.
• Check 24V.
NO FLUE TEMP
CHANGE
The flue temperature did not change after
the burner started firing.
COMBI SENSOR
FAULT
DHW sensor is not connected (combi only).
• Verify that the flue sensor is installed.
• Check the sensor and its associated wiring. Repair or
replace the sensor or wiring if damaged.
• Check the DHW sensor and its associated wiring.
Repair or replace as needed.
• Check the sensors and their associated wiring.
Repair or replace the sensor or wiring if damaged.
The inlet sensor has been disconnected.
LOCKOUT INLET
SENSOR FAULT
• Measure the resistance of the sensors and compare
the resistance to the tables on page 77 of this
manual.
• Replace the sensor if necessary.
• Check the sensors and their associated wiring.
Repair or replace the sensor or wiring if damaged.
The inlet sensor has been shorted.
• Measure the resistance of the sensors and compare
the resistance to the tables on page 77 of this
manual.
• Replace the sensor if necessary.
• Check the sensors and their associated wiring.
Repair or replace the sensor or wiring if damaged.
OUTDOOR
• Measure the resistance of the sensors and compare
SENSOR MISSING The outdoor sensor has opened or shorted.
the resistance to the tables on page 77 of this
manual.
• Replace the sensor if necessary.
84
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FIRE TUBE COMBI
13
Troubleshooting
Installation & Service Manual
(continued)
Table 13-3 (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Boiler Interface
FAULT
CAUSE
CORRECTIVE ACTION
• Verify DHW flow is at least 0.4 gpm.
Flow switch is not triggering a DHW demand
(red light on flow switch sensor does not turn
on during a DHW draw).
• Check wiring harness connections between the low
voltage connection board connector CN4 and the
flow switch sensor.
• Verify that voltage between wires CN4-8 (Blue) and
CN4-3 (Red) is 9 - 10 Vdc. If no voltage, replace Low
Voltage Connection Board.
• Replace flow switch sensor.
Flow switch input not received by main
control board (red light on flow switch
sensor turns on during a DHW draw, but
No Hot Water combi boiler does not start a DHW Call for
Heat).
at Faucets
• Check wiring harness connections between the Low
Voltage Connection Board and the main control
board.
• Replace Low Voltage Connection Board.
• Replace Main Control Board.
• Check wiring harness connections between the Low
Voltage Connection Board (CN4) and the combi
diverter valve motor.
Diverter valve is not in DHW position
(heated boiler water is being provided to
the space heating system rather than to
the combi plate heat exchanger.
• Check that diverter valve motor is operating.
• Verify that the voltage between wire CN4-2 (Black) and
ground is 24 Vac during a DHW demand.
• Replace combi diverter valve motor, Low Voltage
Connection Board, or wire harness.
DHW Water
is not Hot
Enough
DHW set point is too low.
• Set DHW Setpt to the appropriate temperature based
on the anti-scald mixing valve set point.
Anti-scald mixing valve set point is too low.
• Verify the anti-scald mixing valve is set to the desired
temperature.
DHW flow rate is too high (combi boiler
is firing at 100% in DHW Mode, but DHW
temperature on screen is lower than the
DHW Setpt on the screen).
• During maximum flow conditions at all fixtures, adjust
the field supplied flow control valve at the outlet of the
mixing valve (or combi DHW outlet) to reduce the hot
water flow until the DHW temperature reaches the
DHW set point.
Combi DHW sensor fault (display unit will
show "Combi Sensor Fault").
• See Combi Sensor Fault.
85
™
FIRE TUBE COMBI
13
Installation & Service Manual
Troubleshooting
Table 13-3 (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Boiler Interface
FAULT
CAUSE
A DHW demand is present.
Combi Boiler
is Running
but Does
Not Supply
Heated Water
to Space
Heating
System
CORRECTIVE ACTION
• Wait until DHW demand has ended, then combi
unit should provide heated water to the space heating
system. The Noble Combi Boiler does not provide
heated water during a DHW demand.
• Check wiring harness connections between the Low
Voltage Connection Board (CN4) and the combi
diverter valve motor.
Diverter valve is not in DHW position (heated
boiler water is being provided to the combi
plate heat exchanger rather than to the
space heating system).
• Check that diverter valve motor is operating.
• Verify that the voltage between wire CN4-1 (Brown)
and ground is 24 Vac during a space heating
demand.
• Replace combi diverter valve motor, Low Voltage
Connection Board, or wire harness.
Space
Heating
System Heat
Emitters Get
Hot During
a DHW
Diverter valve not operating correctly.
Draw and
the Combi
Boiler does
not Provide
Hot Enough
Domestic
Hot Water
86
• Verify diverter valve motor operation. If combi diverter
valve motor is operating correctly, replace the flow
group on the combi water set.
• Verify wiring harness connections between the Low
Voltage Connection Board, and the diverter valve motor,
and between the main control board and the Low
Voltage Connection Board.
• Verify that voltage between CN4-2 (Black) and ground
is 24 Vac and that voltage between CN4-1 (Brown) and
ground is 0 Vac. If voltages are incorrect, replace the
Low Voltage Connection Board, wire harness, or main
control board.
• If voltages are correct and diverter valve motor is not
operating correctly, replace the combi diverter valve
motor.
Installation & Service Manual
™
FIRE TUBE COMBI
13
Troubleshooting
(continued)
Combustion Analysis Procedure
WARNING
1. Turn the main power off to the boiler.
2. Hold the ► plus the▼ button for five (5) seconds to
enter Service Mode.
3. Once the boiler has modulated up to full fire, measure the
combustion. Place the analyzer probe in the fitting on
the flue adapter. The values should be in the range listed
in Table 13-4. The CO levels should be less than 150 ppm
for a properly installed unit.
If the combustion is not within the specified range,
reference Table 13-5 for possible causes and corrective
actions.
Gas valve adjustment procedure
If adjustment of the gas valve is deemed necessary, use the
following procedure:
CAUTION
Propane
Goal
CO2
Range
Target
4.
5.
6.
O2
CO2
O2
8.5% - 10.5% 2.3% - 5.7% 10.0% - 11% 4.1% - 5.6%
9.0%
4.9%
10.5%
Under normal operating conditions this
valve should not need adjusting.
Locate the throttle adjustment screw on the top of the gas
valve, see FIG. 13-2. Using a 2.5 mm Allen wrench, turn
the screw 1/8 turn counterclockwise to increase CO2 levels
or 1/8 turn clockwise to decrease CO2 levels. After one
adjustment on the valve, follow the Combustion Analysis
to measure the combustion.
Table 13-4 Flue Products
Natural Gas
You must replace the cap on the vent
adapter to prevent flue gas spillage into the
room. Failure to comply could result in
severe personal injury, death, or substantial
property damage.
4.9%
Once the combustion analysis is complete, test the safety
shutoff device by turning the manual shutoff switch to
the OFF position and ensuring that the boiler shuts
down and registers an alarm. Turn the manual gas valve
to the ON position and reset the control.
Turn the main power off to the boiler and replace the cap
on the sample port.
Place the boiler back into normal operation.
If combustion is still not within the specified range,
repeat the procedure. This procedure SHOULD NOT
be performed more than four (4) times. If after four (4)
adjustments and the combustion is still not within the
specified range, revisit the possible causes in Table 13-5
(this page) or replace the gas valve.
Figure 13-2 Gas Valve Adjustment
DETAIL A
THROTTLE
ADJUSTMENT
SCREW
THROTTLE
ADJUSTMENT
SCREW
A
DIR #2000534505 00
Table 13-5 Troubleshooting Chart - Combustion Levels
POSSIBLE CAUSE
Vent/Air Intake Length
or Obstruction
Gas Supply Pressure
CORRECTIVE ACTION
• Refer to Section 3 - General Venting for the proper venting and air intake methods for the
Noble Combi Boiler.
• Check for obstructions at the vent/air intake terminals.
• Refer to Section 7 - Gas Connections for the proper gas supply for the Lochinvar Combi
Boiler.
• Refer to page 72 of this manual for burner removal.
Dirty/Damaged Burner
• Replace burner if necessary.
Gas Valve Adjustment
• Refer to this page of the manual for the gas valve adjustment procedure.
87
Installation & Service Manual
™
FIRE TUBE COMBI
14
Diagrams
Figure 14-1 Ladder Diagram (Standard)
120VAC
NEUTRAL
JUNCTION BOX
120V SUPPLY "L"
GROUND
120V SUPPLY "N"
INTEGRATED CONTROL
X1-6
F1
SYSTEM PUMP
RELAY
X1-2
6.3A
F2
SYSTEM
PUMP "L"
SYSTEM
PUMP
X1-4
BOILER PUMP
RELAY
X1-1
1
3.15A
BLOWER
0.8A
X5-9
BOILER
PUMP
3
X1-8
F3
2
BOX DEPICTS
OPTIONAL ITEMS
X1-5
24VDC
SUPPLY
X5-1
BOX DEPICTS
DUAL SENSOR
SINGLE HOUSING
120 VAC
X4-3
INTEGRATED
CONTROL
CONNECTION BOARD
24 VAC
CN3.2
11
FLOW SWITCH
LWCO
CN6-3
12
CN6-1
CN6-4
CN3-5
X4-8
CN6-2
CN3-8
X4-12
24 VAC
13
14
CN3-7
X4-10
16
CN3-3
X4-4
18
CN3-1
X4-1
CN3-6
X4-9
UNUSED
15
AUX SWITCH
17
HEAT/LOOP
DEMAND
CN4-1
CN4-7
DIV
VALVE
RELAY
19
DIV
VALVE
RELAY
COMBI
DIVERTER
VALVE
CN4-2
CN4-3
-9V
SUPPLY
AIR HANDLER
ENABLE
20
DIV
VALVE
RELAY
COIL
DHW FLOW
SWITCH
CN4-4
CN3-4
X4-5
X5-2
CN4-8
X5-10
DISPLAY
INTEGRATED
CONTROL
AIR PRESSURE
X5-11
SWITCH
X2-2
GASVALVE
X2-1
GAS VALVE
RELAYS
X7
INLET
SENSOR S2
OPERATING
SENSOR S1a
HIGH LIMIT
SENSOR S1b
FLUE
SENSOR S3a
FLUE
SENSOR S3b
-T
-T
-T
-T
-T
X5-6
BLOWER
X5-4
A
X5-5
CASCADE
B
SHIELD
OUTDOOR
SENSOR
SYSTEM
SENSOR
CN4-5
COMBI DHW
SENSOR
CN4-6
2
X5-16
4
X5-8
X5-15
TR2
X5-13
SPARK ROD
X5-14
CONNECTION BOARD
1
2
3
4
5
UNUSED
6
7
8
9
10
X5-7
5
X5-12
CAUTION
SHIELD
1
CN5
X6
CN5
X6
CN5
X6
CN5
X6
CN5
X6
CN5
X6
CN5
X6
HIGH VOLTAGE SPARK LEAD
LOW VOLTAGE
120 VAC
HIGH VOLTAGE
Notes:
1. All wiring must be installed in accordance with: local, state, provincial and national code requirements per either N.E.C. in
USA or C.S.A. in Canada.
2. If any original equipment wire as supplied with the appliance must be replaced, it must be replaced with wire having same
wire gauge (AWG) and rated for a minimum of 105°C. Exceptions: Replacement high voltage spark lead and ribbon cables
must be purchased from the factory. Use of a non-approved spark lead or ribbon cables can lead to operational problems
which could result in non-repairable damage to the integrated controller or other components.
3. Actual connector block locations may vary from those shown on diagrams. Refer to actual components for proper connector
block locations when using diagrams to troubleshoot unit.
88
LABEL,LADDER,NKC
100274889 REV B
Installation & Service Manual
™
FIRE TUBE COMBI
14
Diagrams
(continued)
Figure 14-2 Wiring Diagram (Standard)
DISPLAY
LOW VOLTAGE
120 VAC
HIGH VOLTAGE
INTEGRATED
CONTROL
CONNECTION BOARD
CN1
1
2
3
4
5
6
7
8
9
10
SHIELD
A
CASCADE
X-7
B
SHIELD
SYSTEM
SENSOR
OUTDOOR
SENSOR
JUNCTION
BOX
X1-3
X1-2
BOX DEPICTS
OPTONAL ITEMS
PR
SYSTEM
PUMP
G
CN5
L
GND
X6
N
X1-6
X1-5
BK
W
X1-8
X1-4
G
BR
X1-1
R
120V
SUPPLY
G
BOILER
PUMP
TRANSFORMER
24 VAC
LOW
WATER
CUT OFF
COM
CN6-1
CN6-2
CN6-3
CN6-4
RW G
1 2 3
BLOWER
1 2 3 4 5
CN3
CN2
FLOW
SWITCH
AUX LIM
HEAT/LOOP
DEMAND
AIR HANDLER
CONTACTS
CN3-8
CN3-7
CN3-6
CN3-5
CN3-4
CN3-3
CN3-2
CN3-1
11
12
13
14
15
16
17
18
19
20
K1
FLOW
SWITCH
CIRCUIT
NC
COM
NO
BK
BK
BK
BK
BK
BK
BK
BK
X4-12
X4-10
X4-9
X4-8
X4-5
X4-4
X4-3
X4-1
X5-7
X5-16
R
T
X5-8
W
X5-15
BK
X5-9
Y
X5-1
BL
X5-2
O
X5-10
P
X5-11
O/BK
X5-4
R/BK
AIR PRESSURE SWITCH
-T
OPERATING SENSOR S1a
-T
X5-12
HIGH LIMIT SENSOR S1b
GY
CN4-8
CN4-4
CN4-3
CN4-6
CN4-5
CN4-7
CN4-2
CN4-1
-T
X5-6
INLET SENSOR S2
P/BK
-T
X5-5
FLUE SENSOR S3a
W/BK
-T
X5-13
Y
X2-2
BK
X2-1
Y
X1-7
W/R
TR2
COMBI DIVERTER
VALVE
COMBI DHW
SENSOR
FLUE SENSOR S3b
PR
X5-14
GAS VALVE
@24VAC
FLAME SENSOR
G
SPARK
ROD
CAUTION HIGH VOLTAGE SPARK LEAD
DHW FLOW
SWITCH
BOX DEPICTS
OPTIONAL ITEMS
BOX DEPICTS
DUAL SENSOR
SINGLE HOUSING
Notes:
1. All wiring must be installed in accordance with: local, state, provincial and national code requirements per either N.E.C. in USA or C.S.A. in Canada.
2. If any original equipment wire as supplied with the appliance must be replaced, it must be replaced with wire having same wire gauge (AWG) and rated for a
minimum of 105°C. Exceptions: Replacement high voltage spark lead and ribbon cables must be purchased from the factory. Use of a non-approved spark lead
or ribbon cables can lead to operational problems which could result in non-repairable damage to the integrated controller or other components.
3. Actual connector block locations may vary from those shown on diagrams. Refer to actual components for proper connector block locations when using
diagrams to troubleshoot unit.
LABEL,WIRING,NKC
100273313 REV B
89
™
FIRE TUBE COMBI
Notes
90
Installation & Service Manual
™
FIRE TUBE COMBI
Installation & Service Manual
Notes
91
Revision A (PCP #3000004508 / CN #500004666) initial release.
Revision B (PCP #3000005203 / CN #500005353) reflects the addition
of the DHW flow switch filter cleaning section and the Noble logo.
Revision C (PCP #3000005203 / CN #500005353) reflects updates
made to the mixing valve statements.
Revision D (PCP# 3000006133 / CN# 500007549) reflects the addition
of PVC-DWV vent fitting in Table 3D on page 18.
Revision E (PCP #3000008325 / CN # 500008312) reflects the addition
of parameter values and cleaning instructions for the sanitary bypass
filter in the Combi waterset, along with edits made to pages 18, 39,
and 58.
Revision F (PCP #3000010352 / CN# 500010041) reflects the removal
of the flow switch information on pages 49, 50, and 79.
Revision G (PCP# 3000009959 / CN# 500009745) reflects changes
made to water chemistry information on pages 3, 7, 33-34, 36-39,
41-43, 52-53, 69, and 71.
Revision H (PCP #3000010423 / CN #500010150) reflects an update to
the neutralizer information on page 51.
Revision J (PCP #3000010561 / CN #500010149) reflects an update
to the vent increase notice on page 16 and the bird screen information
on page 27.
Revision K (PCP #3000010778_ 3000021144 / CN #500010568)
reflects updates made to high altitude on page 6, number 6 along with
edits to pages 41 - 43.
MM #100275091_DIR #2000533998_Rev K
10/17
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