Service manual | Canon VB-C500D Security Camera User Manual

CB-CW(E)-i&s-06
INSTALLATION AND SERVICE MANUAL
HYDRONIC HEATING BOILERS and
DOMESTIC WATER HEATERS
495,000 - 2,065,000 Btu/hr MODELS
 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.
– Do not store or use
gasoline
or
other
flammable vapors and
liquids in the vicinity of
this or any other appliance.
WHAT TO DO IF YOU SMELL
GAS
• Do not try to light any
appliance.

 WARNING: Do not use
this appliance 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.
WARNING: Improper
installation, adjustment,
alteration,
service
or
maintenance can cause
property damage, personal
injury,
exposure
to
hazardous materials or
loss of life. Refer to this
manual. Installation and
service must be performed
by a qualified installer,
service agency or the gas
supplier. This unit contains
materials that have been
identified as carcinogenic,
or possibly carcinogenic,
to humans.
• Do not touch any
electric switch; do not
use any phone in your
building.
• Immediately call your
gas supplier from a
neighbors
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.
Save this manual for future reference.
Hydronic Heating Boilers and
Domestic Water Heaters
Table of Contents
Table of Contents
Installation with a Chilled Water System . . . . . . . . . . .26
General Product Information . . . . . . . . . . . . . . . . . . . . . . . . .3
Special Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
Unpacking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
Warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
Safety Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
Product Identification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
Locating Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
Clearances from Combustible Construction . . . . . . . . . .6
Base for Combustible Floors . . . . . . . . . . . . . . . . . . . . .6
Freeze Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
Pump Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
Hydronic System Antifreeze . . . . . . . . . . . . . . . . . . . . . .7
Outdoor Boiler Installation . . . . . . . . . . . . . . . . . . . . . . .7
Shutdown and Draining . . . . . . . . . . . . . . . . . . . . . . . . .7
Freeze Protection for a Heating Boiler System . . . . . . . . . . .8
Combustion and Ventilation Air . . . . . . . . . . . . . . . . . . .8
Combustion Air Filter . . . . . . . . . . . . . . . . . . . . . . . . . . .8
Combustion Air Options . . . . . . . . . . . . . . . . . . . . . . . . .9
Exhaust Fans . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
Venting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
General Information . . . . . . . . . . . . . . . . . . . . . . . . . . .10
Venting Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
Vertical Vent Termination Clearances and Location . .10
Vent System Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
Barometric Damper Location . . . . . . . . . . . . . . . . . . . .12
1. Conventional Negative Draft Venting . . . . . . . . . . .13
2. Outdoor Installation Venting . . . . . . . . . . . . . . . . . .14
Connecting to Gas Supply . . . . . . . . . . . . . . . . . . . . . . . . . .16
Gas Pressure Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
Gas Piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
Connecting Gas Piping to Unit . . . . . . . . . . . . . . . . . . .17
Gas Train and Controls . . . . . . . . . . . . . . . . . . . . . . . . .17
Combination Gas Valves . . . . . . . . . . . . . . . . . . . . . . .18
Venting of Combination Gas Valves . . . . . . . . . . . . . .18
Checking Gas Supply Pressure . . . . . . . . . . . . . . . . . . .18
Gas Manifold Pressure Adjustment . . . . . . . . . . . . . . .19
Connecting to Water Supply . . . . . . . . . . . . . . . . . . . . . . . . .20
Inlet and Outlet Connections . . . . . . . . . . . . . . . . . . . .20
Relief Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
Water Flow Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
Low Water Cutoff . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
Connecting to Electrical Supply . . . . . . . . . . . . . . . . . . . . . .21
Terminal Strip Connection Options . . . . . . . . . . . . . . .22
Boiler System Piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
Primary/Secondary Boiler Piping . . . . . . . . . . . . . . . . .24
Boiler Flow Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27
Boiler Bypass Requirements . . . . . . . . . . . . . . . . . . . . .27
Temperature/Pressure Gauge . . . . . . . . . . . . . . . . . . . . .27
Filling the System . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27
Water Treatment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28
Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28
Lighting Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . .28
To Turn Off Gas To Appliance . . . . . . . . . . . . . . . . . . .29
Setting Temperature Control . . . . . . . . . . . . . . . . . . . . .29
Locating Temperature Control . . . . . . . . . . . . . . . . . . .29
Temperature Control Settings . . . . . . . . . . . . . . . . . . . .30
Outdoor Air Reset Option . . . . . . . . . . . . . . . . . . . . . . .31
Boiler Operating Temperature Control . . . . . . . . . . . . .31
Temperature Control Sensors . . . . . . . . . . . . . . . . . . . .32
Placement of Sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32
Remote Mounting of Sensor . . . . . . . . . . . . . . . . . . . . .33
Hot Surface Ignition System . . . . . . . . . . . . . . . . . . . . . . . . .33
Operation and Diagnostic Lights . . . . . . . . . . . . . . . . . . . . .35
Domestic Water Heaters . . . . . . . . . . . . . . . . . . . . . . . . . . . .36
Water Velocity Control . . . . . . . . . . . . . . . . . . . . . . . . .36
Water Chemistry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
Pipe Size Requirements . . . . . . . . . . . . . . . . . . . . . . . .37
Circulating Pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
Minimum Pump Performance . . . . . . . . . . . . . . . . . . . .38
Heat Exchanger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38
Potable Hot Water Temperature Control Settings . . . . .38
Location of Cold Water Supply Piping Connections . .39
High Water Temperature Limit Control . . . . . . . . . . . .39
Optional Relief Valve . . . . . . . . . . . . . . . . . . . . . . . . . .39
Thermal Expansion . . . . . . . . . . . . . . . . . . . . . . . . . . . .39
Cathodic Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . .39
Cleaning and Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . .40
Flue Gas Passageways Cleaning Procedures . . . . . . . . . . . .40
Burner Removal and Cleaning . . . . . . . . . . . . . . . . . . .40
Heat Exchanger Cleaning . . . . . . . . . . . . . . . . . . . . . . .41
Electrical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41
Combustion and Ventilation Air . . . . . . . . . . . . . . . . . .41
Adjusting Differential Air Pressure . . . . . . . . . . . . . . . .41
Servicing Hot Surface Igniter and Ignition Module . . .43
Ignition System Checkout . . . . . . . . . . . . . . . . . . . . . . .44
Sequence of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44
Low Temperature Return Water Systems . . . . . . . . . . .25
Radiant Floor and Snow Melt Heating Systems . . . . . .25
Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
Schematic/Wiring Diagrams . . . . . . . . . . . . . . . . . . . . . . . . .47
Revision Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . .Back Cover
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Installation and
Service Manual
tube may be caused by too much water velocity through
the tubes and is not covered by the appliance
manufacturer's warranty (see System Temperature Rise
Chart on page 26 for flow requirements).
GENERAL PRODUCT
INFORMATION
Special Instructions
SAFETY INFORMATION
This manual supplies information for the installation, operation
and servicing of the appliance. Read and understand this manual
completely before installing unit.
The information contained in this manual is intended for use
by qualified professional installers, service technicians or gas
suppliers. Consult your local expert for proper installation or
service procedures.
Installation and service must be performed by a qualified service
installer, service agency, or the gas supplier.
IMPORTANT: Read this owner's manual carefully
and completely before trying to install, operate, or
service this unit. Improper use of this unit can
cause serious injury or death from burns, fire,
explosion, electrical shock, and carbon monoxide
poisoning.
Unpacking
Upon receiving equipment, check for signs of shipping damage.
Pay particular attention to parts accompanying the boiler which
may show signs of being hit or otherwise being mishandled.
Verify total number of pieces shown on packing slip with those
actually received. In case there is damage or a shortage,
immediately notify the carrier.

DANGER: Carbon Monoxide poisoning may
lead to death!
Codes
IMPORTANT: Consult and follow local building and
fire regulations and other safety codes that apply
to this installation. Consult your local gas utility
company to authorize and inspect all gas and flue
connections.
The equipment shall be installed in accordance with those
installation regulations in force in the local area where the
installation is to be made. These shall be carefully followed in all
cases. Authorities having jurisdiction shall be consulted before
installations are made. In the absence of such requirements, the
installation shall conform to the latest edition of the National Fuel
Gas Code, ANSI Z223.1 and/or CAN/CGA-B149 Installation
Code. Where required by the authority having jurisdiction, the
installation must conform to American Society of Mechanical
Engineers Safety Code for Controls and Safety Devices for
Automatically Fired Boilers, ASME CSD 1. All boilers conform
to the latest edition of the ASME Boiler and Pressure Vessel
Code, Section IV.

WARNING: Should overheating occur or the
gas supply fail to shut off, do not turn off or
disconnect the electrical supply to the pump.
Instead, shut off the gas supply at a location
external to the unit.

WARNING: To minimize the possibility of
serious personal injury, fire or damage to your unit,
never violate the following safety rules.
Warranty
Factory warranty (shipped with unit) does not apply to units
installed or operated improperly.
1. This unit is only for use with the type of gas indicated on the
rating plate.
2. If you smell gas
• shut off gas supply
• do not try to light any appliance
• do not touch any electrical switch; do not use any
phone in your building
• immediately call your gas supplier from a neighbor's
phone. Follow the gas supplier's instructions
• if you cannot reach your gas supplier, call the fire
department
In most cases, improper installation or system design causes
most operating problems.
1. Excessive water hardness causing a lime build up in the
copper tube is not the fault of the equipment and is not
covered under the appliance manufacturer's warranty (see
Water Treatment, page 28 and Water Chemistry, page 37).
2. Excessive pitting and erosion on the inside of the copper
3
Hydronic Heating Boilers and
Domestic Water Heaters
3. Boilers and water heaters are heat producing appliances. To
avoid damage or injury, do not store materials against the
appliance or the vent-air intake system. Use proper care to
avoid unnecessary contact (especially children) with the
appliance and vent-air intake components. Follow all
clearances from combustibles contained in this manual.
4. Never cover your unit, lean anything against it, store trash or
debris near it, stand on it or in any way block the flow of
fresh air to your appliance.
5. UNDER NO CIRCUMSTANCES must flammable materials
such as gasoline or paint thinner be used or stored in the
vicinity of this appliance, vent-air intake system or any
location from which fumes could reach the appliance or ventair intake system.
6. Appliance surfaces become hot during operation. Be careful
not to touch hot surfaces. Keep all adults, children, and
animals away from an operating hot unit. Severe burns can
occur.
7. You must take adequate care to prevent scald injury when
storing water at elevated temperatures for domestic use.
8. This unit must have an adequate supply of fresh air during
operation for proper gas combustion and venting.
9. Make sure all exhaust venting is properly installed and
maintained. Improper venting of this unit could lead to
increased levels of carbon monoxide.
10. Do not use this boiler if any part has been under water.
Immediately call a qualified service technician to replace the
boiler. The possible damage to a flooded boiler can be
extensive and present numerous safety hazards. Any
appliance that has been under water must be replaced.
11. Do not alter this unit in any way. Any change to this unit or
its controls can be dangerous.
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Installation and
Service Manual
PRODUCT
IDENTIFICATION
Front View
Rear View
Figure 1 – Front and Rear View
5
Hydronic Heating Boilers and
Domestic Water Heaters
INSTALLATION
Clearances from Combustible
Construction
This unit meets the safe lighting performance criteria with the
gas manifold and control assembly provided, as specified in
the ANSI standards for gas-fired units, ANSI Z21.13/CSA 4.9
and ANSI Z21.10.3/CSA 4.3.
Maintain minimum specified clearances for adequate
operation. Allow sufficient space for servicing pipe
connections, pump and other auxiliary equipment, as well as
the unit. See rating plate for specific service clearance
requirements.
LOCATING UNIT
1. Maintain all clearances from combustible construction when
locating unit. See Clearances from Combustible
Construction, this page.
Right Side
3" (7.5 cm)
Rear
3" (7.5 cm) (3" min. from any surface)
2. Locate the unit so that if water connections should leak,
water damage will not occur. When such locations cannot
be avoided, install a suitable drain pan that is well-drained
under the unit. The pan must not restrict combustion air
flow. The appliance manufacturer is not responsible for
water damage in connection with this unit, or any of its
components.
Left Side
6" (15cm) (24" (0.61m) suggested for
service)
Front
Alcove* (30" (0.76m) suggested for
service)
Top
3" (7.5cm)
Flue
1" (25.4mm)
3. Install indoor units so that the ignition system components
are protected from any water while operating or during
service.
Hot Water Pipes 1" (25.4mm)
4. Appliances located in a residential garage and in adjacent
spaces that open to the garage and are not part of the living
space of a dwelling unit must be installed so that all
burners and burner ignition devices have a minimum
clearance of not less than 18" (46cm) above the floor. The
appliance must be located or protected so that it is not
subject to physical damage by a moving vehicle.
*An Alcove is a closet without a door.
Note: No additional clearance is needed on the right side of the
unit for the observation port. An observation port is located on
both the right and left side of the unit.
5. DO NOT install this appliance in any location where
gasoline or flammable vapors are likely to be present.
6. You must install unit on a level, non-combustible floor.
7. Do not install unit directly on carpet or other combustible
material. A concrete-over-wood floor is not considered
non-combustible. Maintain required clearances from
combustible surfaces.
If installing unit in an area with a combustible floor, you
must use a special combustible floor base. See Base for
Combustible Floors, this page.
8. For outdoor models, you must install an optional vent kit.
Instructions for mounting the vent kit are included in the
venting section. Do not install outdoor models directly on
the ground. You must install the outdoor unit on a concrete,
brick, block, or other non-combustible pad. Outdoor
models have additional special location and clearance
requirements. See Outdoor Installation Venting, page 14.
A wind proof cabinet protects the unit from weather.
Figure 2 - Clearances from Combustible Construction
Base for Combustible Floors
There is no manufactured combustible floor base kit available
for 985,000 - 2,065,000 Btu/hr models. You must construct a
6
Installation and
Service Manual

base for combustible floor installation. Install unit over a base
of hollow clay tiles or concrete blocks from 8" to 12" thick and
extending at least 24" beyond the unit sides. Place tiles or
blocks so that the holes line up horizontally to provide a clear
passage through the tiles or blocks. Place a 1/2" fireproof
millboard over the top of the tile or block base. Place a 20gauge sheet metal cover over the fireproof millboard. Center
the unit on the base. Also follow this procedure if electrical
conduit runs through the floor beneath the unit. This base must
meet all local fire and safety codes.
CAUTION: A mechanical room operating
under a negative pressure may experience a
down draft in the flue of a boiler which is not
firing. The cold outside air pulled down the flue
may freeze a heat exchanger. This condition
must be corrected to provide adequate freeze
protection.
Hydronic System Antifreeze
TABLE - A
COMBUSTIBLE FLOOR KITS
Input Btu/hr
Kit Number
495,000
645,000
745,000
Freeze protection for a heating boiler or hot water supply
boiler using an indirect coil can be provided by using hydronic
system antifreeze. Follow the appliance manufacturers
instructions. Do not use undiluted or automotive type
antifreeze.
CFK3302
CFK3303
CFK3304
Outdoor Boiler Installation
Adequate hydronic system antifreeze must be used. A snow
screen should be installed to prevent snow and ice
accumulation around the unit or its venting system.
FREEZE PROTECTION
Shut-Down and Draining
Although these units are CSA International design certified for
outdoor installations, such installations are not recommended
in areas where the danger of freezing exists. You must provide
proper freeze protection for outdoor installations, units
installed in unheated mechanical rooms or where temperatures
may drop to the freezing point or lower. If freeze protection is
not provided for the system, a low ambient temperature alarm
is recommended for the mechanical room. Damage to the unit
by freezing is non-warrantable.
If for any reason, the unit is to be shut off, the following
precautionary measures must be taken:
1. Shut off gas supply.
2. Shut off water supply.
3. Shut off electrical supply
4. Drain the unit completely. Remove one threaded plug or
bulbwell from the inlet side of the front header and one
from the outlet side of the front header on the heat
exchanger. Blow all water out of the heat exchanger (see
Figure 3).
Anytime the temperature measured at any of the sensors
(except the outside air temperature sensor) drops below 40°F,
the control turns on the pump contact and the alarm relay. The
pump will shut off when both sensors are above 50°F.
5. Drain pump and piping.
Pump Operation
This unit is equipped with a pump delay of 30 seconds. If
continuous operation of the pump is desired, the pump must be
electrically connected to another circuit. Connection of the
pump to this unit will provide intermittent pump delay
operation.
Location
Locate indoor boilers and hot water supply boilers in a room
having a temperature safely above freezing [32°F (0°C)].
Figure 3 - Draining Unit
7
Hydronic Heating Boilers and
Domestic Water Heaters
Check this filter every month and replace when it becomes
dirty. The filter size is 12" x 16" x 1" (30.5cm x 40.6cm x
2.5cm) . You can find this commercially available filter at any
home center or HVAC supply store.
INSTALLATION
Continued
Freeze Protection for a Heating
Installing Combustion Air Filter
Boiler System (if required)
1. Use only properly diluted inhibited glycol antifreeze
designed for hydronic systems. Inhibited propylene glycol
is recommended for systems where incidental contact with
drinking water is possible.
To install the filter(s), remove the combustion air inlet panel(s).
The 985,000 - 1,435,000 Btu/hr models have one combustion air
inlet panel located on the left front of the unit (see Figure 4). The
1,795,000 and 2,065,000 Btu/hr models have two combustion air
inlet panels located on the left and right front of the unit (see
Figure 5).

WARNING: Do not use undiluted or
automotive type antifreeze.
1. Loosen knurled knob at the bottom of the control panel
cover.
2. A solution of 50% antifreeze will provide maximum
protection of approximately -30°F.
2. Pull the bottom of the panel(s) out and down to remove.
3. Follow the instructions from the antifreeze manufacturer.
Quantity of antifreeze required is based on total system
volume including expansion tank volume.
4. Replace combustion air inlet panel(s).
3. Place filter(s) in opening(s).
4. Glycol is denser than water and changes the viscosity of
the system. The addition of glycol will decrease heat
transfer and increase frictional loss in the boiler and related
piping. A larger pump with more capacity (15% to 25%
more) may be required to maintain desired flow rates and
prevent a noise problem in a glycol system.
5. Local codes may require a back flow preventer or actual
disconnect from city water supply when antifreeze is
added to the system.
COMBUSTION AND VENTILATION
AIR
Figure 4 - Installing Combustion Air Filter, 985,000 1,435,000 Btu/hr Models
Provisions for combustion and ventilation air must be in
accordance with Section 5.3, Air for Combustion and
Ventilation, of the latest edition of the National Fuel Gas Code,
ANSI Z223.1, in Canada, the latest edition of CAN/CGAB149 Installation Code for Gas Burning Appliances and
Equipment, or applicable provisions of the local building
codes.
Provide properly-sized openings to the equipment room to
assure adequate combustion air and proper ventilation when
the unit is installed with conventional venting or sidewall
venting.
Combustion Air Filter
The 985,000 - 2,065,00 Btu/hr models have a standard air
filter(s) located behind the combustion air inlet panel(s). This
filter helps ensure clean air is used for the combustion process.
Figure 5 - Installing Combustion Air Filters, 1,795,000 and
2,065,000 Btu/hr Models
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Installation and
Service Manual
Combustion Air Options

CAUTION: Under no circumstances
should the mechanical room ever be under a
negative pressure. Particular care should be
taken where exhaust fans, attic fans, clothes
dryers, compressors, air handling units, etc.,
take away air from the unit.
1. Outside Combustion Air, No Ducts You can direct
outside combustion air to this unit using either one or two
permanent openings.
One Opening
The opening must have a minimum free area of one square
inch per 3000 Btu input (7cm2 per kW). You must locate this
opening within 12" (30cm) of the top of the enclosure.
Figure 7 - Outside Combustion Air - Two Openings
2. Outside Combustion Air, Using Ducts
You can direct outside combustion air to this unit using two air
ducts to deliver the air to the boiler room.
Each of the two openings must have a minimum free area of
one square inch per 2000 Btu input (11cm2 per kW).
Figure 6 - Outside Combustion Air - Single Opening
Two Openings
The combustion air opening must have a minimum free area of
one square inch per 4000 Btu input (5.5cm2 per kW). You must
locate this opening within 12" (30cm) of the bottom of the
enclosure.
Figure 8 - Outside Combustion Air Through Ducts
3. Combustion Air from Interior Space
You can direct combustion air to this unit using air from an
adjoining interior space. You must provide two openings from
the boiler room to the adjoining room.
The ventilation air opening must have a minimum free area of
one square inch per 4000 Btu input (5.5cm2 per kW). You must
locate this opening within 12" (30cm) of the top of the
enclosure.
Each of the two openings must have a net free area of one
square inch per 1000 Btu input (22cm2 per kW), but not less
than 100 square inches (645cm2).
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Hydronic Heating Boilers and
Domestic Water Heaters
VENTING
INSTALLATION
Continued
General Information
You must supply adequate combustion and ventilation air to
this unit. You must provide minimum clearances for the vent
terminal from adjacent buildings, windows that open, and
building openings. Follow all requirements set forth in the
latest edition of the National Fuel Gas Code, ANSI Z223.1, in
Canada, the latest edition of CAN/CGA Standard B149
Installation Code for Gas Burning Appliances and Equipment
or applicable local building codes. Vent installations for
connection to gas vents or chimneys must be in accordance
with Part 7, "Venting of Equipment" of the above-mentioned
standards.
IMPORTANT: Examine the venting system at
least once each year. Check all joints and vent
pipe connections for tightness. Also check for
corrosion or deterioration. If you find any
problems, correct them at once.
Figure 9 - Combustion Air from Interior Space
All dimensions are based on net free area in square inches.
Metal louvers or screens reduce the free area of a combustion
air opening a minimum of approximately 25%. Check with
louver manufacturers for exact net free area of louvers. Where
two openings are provided, one must be within 12" (30 cm) of
the ceiling and one must be within 12" (30 cm) of the floor of
the mechanical room. Each opening must have a minimum net
free area as specified in TABLE-C, page 12. Single openings
shall be installed within 12" (30 cm) of the ceiling.
Venting Support
Support horizontal portions of the venting system to prevent
sagging. Provide an upward slope of at least 1/4 inch per foot
(21mm/m) on all horizontal runs from the unit to the vertical
flue run or to the vent terminal on sidewall venting
installations.
The combustion air supply must be completely free of any
flammable vapors that may ignite or chemical fumes which
may be corrosive to the appliance. Common corrosive
chemical fumes which must be avoided are fluorocarbons and
other halogenated compounds, most commonly present as
refrigerants or solvents, such as Freon, trichlorethylene,
perchlorethylene, chlorine, etc. These chemicals, when
burned, form acids which quickly attack the heat exchanger
finned tubes, headers, flue collectors, and the vent system. The
result is improper combustion and a non-warrantable,
premature appliance failure.
Do not use an existing chimney as a raceway if another
appliance or fireplace is vented through the chimney. The
weight of the venting system must not rest on the unit. Provide
adequate support of the venting system. Follow all local and
applicable codes. Secure and seal all vent connections. Follow
the installation instructions from the vent material
manufacturer.
Vertical Vent Termination Clearances
and Location
The vent terminal should be vertical and exhaust outside the
building at least 2 feet (0.61m) above the highest point of the
roof within a 10 foot (3.05m) radius of the termination.
Exhaust Fans
Any fan or equipment which exhausts air from the boiler room
may deplete the combustion air supply and/or cause a down
draft in the venting system. Spillage of flue products from the
venting system into an occupied living space can cause a very
hazardous condition that must be corrected immediately. If a
fan is used to supply combustion air to the boiler room, the
installer must make sure that it does not cause drafts which
could lead to nuisance operational problems with the boiler.
The vertical termination must be a minimum of 3 feet (0.91m)
above the point of exit.
A vertical termination less than 10 feet (3.05m) from a parapet
wall must be a minimum of 2 feet (0.61m) higher than the
parapet wall.
10
Installation and
Service Manual
You must locate the air inlet termination elbow at least 12"
(30cm) above the roof or above normal snow levels.
Keep the vent cap clear of snow, ice, leaves, and debris to
avoid blocking the flue.
Figure 12 - Vent Termination from Flat Roof 10' or Less from
Parapet Wall
Figure 10 - Vent Termination from Peaked Roof - 10' or
Less From Ridge
IMPORTANT: Vent terminations are not shown in
Figures 10, 11, 12, and 13. Make sure all vertical
vents are installed with vent terminations
recommended by the vent manufacturer.
Figure 13 - Vent Termination from Flat Roof More Than 10'
from Parapet Wall

CAUTION: Units which are shut down or
will not operate may experience freezing due to
convective air flow in the flue pipe, through the
air inlet, or from negative pressure in the
mechanical room. In cold climates, operate pump
continuously to help prevent freezing of boiler
water. Provide proper freeze protection. See
Freeze Protection, page 7.
Figure 11 - Vent Termination from Peaked Roof More Than
10' From Ridge
TABLE-A
Flue Pipe Sizes
11
Hydronic Heating Boilers and
Domestic Water Heaters
INSTALLATION
2. Outdoor Installation Venting
This option uses the installation of special air inlet and vent
caps on the unit. See page 13 for venting details.
Continued
All units are shipped from the factory equipped for
conventional negative draft venting. All other optional vent
systems require the installation of specific vent kits and
venting materials. The following is a detailed explanation of
the installation requirements for each venting system,
components used and part numbers of vent kits for each model.
TABLE - B
Flue Pipe Sizes
Input
Flue
Btu/hr
Size
495,000
6"
645,000
8"
745,000
8"
985,000
10"
1,255,000
12"
1,435,000
12"
1,795,000
14"
2,065,000
14"
Barometric Damper Location
Any venting system option that requires a barometric damper
must adhere to the following directions for optimum
performance.
The preferred location for the barometric damper is in a tee or
collar installed in the vertical pipe rising from the unit’s flue
outlet. The barometric damper MUST NOT be installed in a
bull head tee installed on the unit’s flue outlet. The tee or collar
containing the barometric damper should be approximately
three feet vertically above the connection to the unit’s flue
outlet. This location ensures that any positive velocity pressure
from the unit’s internal combustion fan is dissipated and the
flue products are rising due to buoyancy generated from the
temperature of the flue products. Adjust weights on damper to
ensure that draft is maintained within the specified ranges.
Vent System Options
This unit has two venting options.
1. Conventional Negative Draft Venting
This option uses a vertical rooftop flue termination.
Combustion air is supplied from the mechanical room. See
page 13 for detailed information.
TABLE–C
Minimum Recommended Combustion Air Supply To Boiler Room
Boiler Input
Combustion Air Source
Outside Air*/2 Openings
Outside Air*/1 Opening
2
2
Inside Air/2 Openings
495,000
125 in (806 cm )
167 in2 (1077 cm2)
500 in2 (3226 cm2)
645,000
163 in2 (1052 cm2)
217 in2 (1400 cm2)
650 in2 (4194 cm2)
745,000
188 in2 (1213 cm2)
250 in2 (1613 cm2)
750 in2 (4839 cm2)
985,000
248 in2 (1,600cm2)
330 in2 (2,129cm2)
990 in2 (6,388cm2)
1,255,000
315 in2 (2,032cm2)
420 in2 (2,710cm2)
1260 in2 (8,130cm2)
1,435,000
360 in2 (2,323cm2)
480 in2 (3,097cm2)
1440 in2 (9,291cm2)
1,795,000
450 in2 (2,903cm2)
600 in2 (3,871cm2)
1800 in2 (11,614cm2)
2,065,000
518 in2 (3,342cm2)
690 in2 (4,452cm2)
2070 in2 (13,356cm2)
*Outside air openings shall directly communicate with the outdoors. When combustion air is drawn from the outside through a duct, the net free area of each of the two openings
must have twice (2 times) the free area required for Outside Air/2 Openings. The above requirements are for the boiler only, additional gas fired units in the boiler room will require
an increase in the net free area to supply adequate combustion air for all units. Combustion air requirements are based on the latest edition of the National Fuel Gas Code, ANSI
Z223.1, in Canada refer to CAN/CGA-B149 Installation Code. Check all local code requirements for combustion air.
12
Installation and
Service Manual
Flue Outlet Piping
1. Conventional Negative Draft
Venting
With this venting option, you must use Type-B double-wall (or
equivalent) vent materials. Vent materials must be listed by a
nationally-recognized test agency for use as vent materials.
Make the connections from the unit vent to the outside stack as
direct as possible with no reduction in diameter. Use the
National Fuel Gas Code venting tables for double-wall vent to
properly size all vent connectors and stacks. Follow the vent
manufacturer's instructions when installing Type-B vents and
accessories, such as firestop spacers, vent connectors,
thimbles, caps, etc.
IMPORTANT: Before installing a venting system,
follow all venting clearances and requirements
found in the Venting, General Information
section, page 10.
Provide adequate clearance to combustibles for the vent
connector and firestop.
When planning the venting system, avoid possible contact with
plumbing or electrical wiring inside walls, ceilings, and floors.
Locate the unit as close as possible to a chimney or gas vent.
Avoid long horizontal runs of the vent pipe, 90° elbows,
reductions and restrictions.
No additional draft diverter or barometric damper is required
on single unit installations with a dedicated stack and a
negative draft maintained between 0.02 to 0.08 inches w.c.
Figure 14 - Conventional Negative Draft Vertical Venting
with Combustion Air Louvers
This option uses Type-B double-wall flue outlet piping. The
blower brings in combustion air. The buoyancy of the heated
flue products cause them to rise up through the flue pipe. The
flue outlet terminates at the rooftop.
Common Venting Systems
You can combine the flue with the vent from any other
negative draft, Category I appliance. Using common venting
for multiple negative draft appliances requires you to install a
barometric damper with each unit. This will regulate draft
within the proper range. You must size the common vent and
connectors from multiple units per the venting tables for TypeB double-wall vents in the latest edition of the National Fuel
Gas Code, ANSI Z223.1 and/or CAN/CGA-B149 Installation
Code.
Negative Draft
The negative draft in a conventional vent installation must be
within the range of 0.02 to 0.08 inches w.c. to ensure proper
operation. Make all draft readings while the unit is in stable
operation (approximately 2 to 5 minutes).
Connect the flue vent directly to the flue outlet opening on the
top of the unit. No additional draft diverter or barometric
damper is needed on single unit installations with a dedicated
stack and a negative draft within the specified range of 0.02 to
0.08 inches w.c. If the draft in a dedicated stack for a single
unit installation exceeds the maximum specified draft, you
must install a barometric damper to control draft. Multiple unit
installations with combined venting or common venting with
other Category I negative draft appliances require each boiler
to have a barometric damper installed to regulate draft within
the proper range.
Common venting systems may be too large when an existing
unit is removed.
At the time of removal of an existing appliance, the following
steps shall be followed with each appliance remaining
connected to the common venting system placed in operation,
while other appliances remaining connected to the common
venting system are not in operation.
1. Seal any unused opening in the common venting system.
2. Visually inspect the venting system for proper size and
horizontal pitch. Make sure there is no blockage or
restriction, leakage, corrosion and other unsafe conditions.
Do not connect vent connectors serving appliances vented by
natural draft (negative draft) to any portion of a mechanical
draft system operating under positive pressure. Connecting to
a positive pressure stack may cause flue products to be
discharged into the living space causing serious health injury.
3. If possible, close all building doors and windows. Close all
doors between the space in which the appliances remaining
connected to the common venting system are located and
other building spaces.
13
Hydronic Heating Boilers and
Domestic Water Heaters
INSTALLATION
Inspection of a Masonry Chimney
A masonry chimney must be carefully inspected to determine
its suitability for the venting of flue products. A clay-tile-lined
chimney must be structurally sound, straight and free of
misaligned tile, gaps between liner sections, missing sections
of liner or any signs of condensate drainage at the breeching or
clean out. If there is any doubt about the condition of a
masonry chimney, it must be relined with a properly-sized and
approved chimney liner system. An unlined masonry chimney
must not be used to vent flue products from this highefficiency unit. An unlined chimney must be relined with an
approved chimney liner system when a new appliance is
being attached to it. Metallic liner systems (Type-B doublewall or flexible or rigid metallic liners) are recommended.
Consult with local code officials to determine code
requirements or the advisability of using or relining a masonry
chimney.
Continued
4. Turn on clothes dryers and any other appliances 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.
5. Close fire place dampers.
6. Place in operation the unit being inspected. Follow the
lighting instructions. Adjust thermostat so unit will operate
continuously.
7. 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.
8. After making sure that each appliance remaining
connected to the common venting system properly vents
when tested as above, return doors, windows, exhaust fans,
fireplace dampers and other gas burning appliances to their
previous conditions of use.
Vertical Vent Termination Clearances
and Location
9. Correct any improper operation of the common venting
system so that the installation conforms to the latest edition
of the National Fuel Gas Code, ANSI Z223.1, in Canada,
the latest edition of CAN/CGA-B149 Installation Code for
Gas Burning Appliances and Equipment. When resizing
any portion of the common venting system, resize to
approach the minimum size as determined using the
appropriate tables of the latest edition of the National Fuel
Gas Code, ANSI Z223.1, in Canada, the latest edition of
CAN/CGA-B149 Installation Code for Gas Burning
Appliances and Equipment.
Follow all vertical venting termination information for
clearances and location under Vertical Vent Termination
Clearances and Location, page 10.
2. Outdoor Installation Venting
IMPORTANT: Before installing a venting system,
follow all venting clearances and requirements
found in the Venting, General Information section,
page 10.
Units are self-venting and can be used outdoors when installed
with the optional outdoor caps. These caps mount directly to the
unit and cover the flue outlet and combustion air inlet openings.
No additional vent piping is required.
Masonry Chimney Installations
A masonry chimney must be properly sized for the installation
of a high efficiency gas-fired appliance. Venting of a high
efficiency appliance into a cold or oversized masonry chimney
can result in operational and safety problems. Exterior
masonry chimneys, with one or more sides exposed to cold
outdoor temperatures, are more likely to have venting
problems. The temperature of the flue products from a high
efficiency appliance may not be able to sufficiently heat the
masonry structure of the chimney to generate proper draft. This
will result in condensing of flue products, damage to the
masonry flue/tile, insufficient draft and possible spillage of
flue products into an occupied living space. Carefully inspect
all chimney systems before installation.

WARNING: Only install outdoor models
outdoors and only use the vent caps supplied by
the appliance manufacturer. Personal injury or
product damage may result if any other cap is
used or if an outdoor model is used indoors.
Properly install all covers, doors and jacket panels
to ensure proper operation and prevent a
hazardous condition.
Combustion air supply must be free of contaminants (see
Combustion and Ventilation Air, page 8). To prevent recirculation
of the flue products into the combustion air inlet, follow all
instructions in this section.
14
Installation and
Service Manual
Flue gas condensate can freeze on exterior walls or on the vent
cap. Frozen condensate on the vent cap can result in a blocked
flue condition. Some discoloration to exterior building or unit
surfaces can be expected. Adjacent brick or masonry surfaces
should be protected with a rust resistant sheet metal plate.
Outdoor Vent/Air Inlet Location
Keep venting areas free of obstructions. Keep area clean and free
of combustible and flammable materials. Maintain a minimum
clearance of 3" (76mm) to combustible surfaces and a minimum
of 3" (76mm) clearance to the air inlet. To avoid a blocked air
inlet or blocked flue condition, keep the air inlet, flue outlet and
drain slot clear of snow, ice, leaves, debris, etc.
The Outdoor Vent Kit
The optional outdoor vent kit is available from the appliance
manufacturer. The outdoor kit part numbers are listed by unit
size. See TABLE-D for kit numbers.
Do not install outdoor models directly on the ground. You must
install the outdoor unit on a concrete, brick, block, or other
non-combustible pad.
You can install the outdoor vent cap and combustion air inlet
panel(s) on the unit (see Figures 15 and 16).
Do not locate unit so that high winds can deflect off of adjacent
walls, buildings or shrubbery causing recirculation.
Recirculation of flue products may cause operational
problems, bad combustion or damage to controls. Locate unit
at least 3 feet (0.91m) from any wall or vertical surface to
prevent wind conditions from affecting performance.
Multiple outdoor unit installations require 48" (1.22m)
clearance between each vent cap. Locate the outdoor cap at
least 48" (1.22m) below and 48" (1.22m) horizontally from
any window, door, walkway or gravity air intake.
Locate the unit at least 10 feet (3.05m) away from any forced
air inlet.
Locate the unit at least 3 feet (0.91m) outside any overhang.
Clearances around outdoor installations can change with time.
Do not allow the growth of trees, shrubs or other plants to
obstruct the proper operation of the outdoor vent system.
Figure 15 - Outdoor Vent Cap Installed on
495,000 - 1,435,000 Btu/hr Models
Do not install in locations where rain from building runoff
drains will spill onto the unit.
TABLE - D
Outdoor Vent Kits
Input
Kit*
Kit*
Btu/hr
w/ Pump
without
Cover
Pump Cover
495,000
ODK3023
ODK3014
645,000
ODK3024
ODK3015
745,000
ODK3024
ODK3015
985,000
ODK3046
ODK3043
1,255,000
ODK3047
ODK3044
1,435,000
ODK3047
ODK3044
1,795,000
ODK3048
ODK3045
2,065,000
ODK3048
ODK3045
TABLE-C
Figure 16 - Outdoor Vent Cap Installed on 1,795,000 and
2,065,000 Btu/hr Models
* These kits include an outdoor vent cap, air inlet hood(s), and gasket.
15
Hydronic Heating Boilers and
Domestic Water Heaters
Gas Piping
INSTALLATION
To safely operate this unit, you must properly size the gas
supply piping. See TABLES- F, G, & H for piping and fitting
requirements. Gas pipe size may be larger than heater
connection.
The gas connection for models 495,000 to 745,000 Btu/hr is
1 1/4" NPT and on models 985,000 to 2,065,000 Btu/hr the
gas connection to these units is 2" NPT.
Continued
CONNECTING TO GAS
SUPPLY
Only supply the gas type specified on the unit's rating plate.
This unit is orificed for operation up to 2000 feet altitude. If
installing above 2000 feet elevation, consult the appliance
manufacturer.
For ease of service, install a union.
Install a manual main gas shutoff valve, outside of the unit gas
connection within six feet of the unit in accordance with the
requirements of the National Fuel Gas Code, ANSI Z223.1.
INLET PRESSURE: Measure inlet pressure at the inlet
pressure tap located upstream of the combination gas valve(s).
You must provide a sediment trap (drip leg) in the inlet of the
gas connection to the unit.
See TABLE-E for maximum and minimum inlet pressures. Do
not exceed the maximum. Minimum inlet pressure is for the
purposes of input adjustment.
TABLE - E
Inlet Pressure
Input
Max.
Min.
495,000 - 745,000 Btu/hr
Nat. Gas
10.5" w.c.
4" w.c.
LP Gas
13" w.c.
8" w.c.
985,000 - 2,065,000 Btu/hr
Nat. Gas
10.5" w.c.
LP Gas
13" w.c.
4.5" w.c.
8" w.c.
MANIFOLD PRESSURE: Measure manifold pressure at the
pressure tap on the downstream side of the combination gas
valves. The gas regulator on the unit's combination gas valve
is adjustable to supply proper manifold pressure for normal
operation. See TABLE-I for net manifold pressure settings.
Figure 17 - 495,000 - 745,000 Btu/hr Gas Line Connection
Example
If you must adjust regulator pressure, follow the instructions
under Gas Manifold Pressure Adjustment, page 19. Do not
increase regulator pressure beyond the specified pressure
setting.
Gas Pressure Test
1. Disconnect the unit from the gas supply piping system
during any piping system pressure testing greater than 1/2
PSIG (3.5kPa).
2. Isolate the unit from the gas supply piping system by
closing a manual shutoff valve during any piping system
pressure testing that is equal to or less than 1/2 PSIG
(3.5kPa).
Figure 18 - 985,000 - 2,065,000 Btu/hr Gas Line Connection
Example
IMPORTANT: Do not block access to the
electrical cover plate when installing the
sediment trap. The sediment trap must be a
minimum of 12 inches from the appliance.
3. Test all gas connections for gas leaks before placing unit in
operation.
16
Installation and
Service Manual
The combination gas valves have an integral vent limiting
device and does not require venting to atmosphere outside the
building. The unit will not operate properly if the reference
hose is removed or a vent to atmosphere is installed.
COMBINATION VALVE
DOWNSTREAM
TEST VALVE
Optional gas controls may require routing of bleeds and vents
to the atmosphere outside the building when required by local
codes.
Connecting Gas Piping to Unit
TO BURNERS
ADDITIONAL VALVES BASED
ON UNIT INPUTS
All gas connections must be made with pipe joint compound Figure 19 - Gas Train Drawing
resistant to the action of liquefied petroleum (L.P.) and natural
TABLE-F
gases. All piping must comply with local codes and
Suggested
Gas
Pipe
Size
for Single Unit Installations
ordinances. Piping installations must comply with approved
Btu/hr
Distance
From Meter (in feet)
standards and practices.
0-50 51-100 101-200 201-300 301-500
1. Make sure gas line is a separate line direct from the meter Input
unless the existing gas line is of sufficient capacity. Verify
495,000
pipe size with your gas supplier.
2. Use new, properly threaded black iron pipe free from 645,000
chips. If you use tubing, make sure the ends are square,
deburred and clean. Make all tubing bends smooth and 745,000
without deformation. Avoid flexible gas connections.
Internal diameter of flexible lines may not provide unit 985,000
with proper volume of gas.
1 1/4"
1 1/4"
1 1/2"
2"
2"
1 1/4"
1 1/2"
2"
2"
2 1/2"
1 1/2"
2"
2"
2 1/2"
2 1/2"
2"
2"
2 1/2"
3"
2 1/2"
1,255,000 2"
2 1/2"
2 1/2"
3"
3"
3. Install a manual main gas shutoff valve at the unit's gas
inlet, outside of the unit.
1,435,000 2 1/2" 2 1/2"
3"
3"
3 1/2"
4. Run pipe or tubing to the unit's gas inlet. If you use tubing,
3"
3"
3 1/2"
3 1/2"
obtain a tube to pipe coupling to connect the tubing to the 1,795,000 2 1/2"
unit's gas inlet.
2,065,000 2 1/2"
3"
3"
3 1/2"
4"
5. Install a sediment trap in the supply line to the unit's gas
For each elbow or tee, add equivalent straight pipe to total length from table below.
inlet (see Figure 17).
Gas Train and Controls
6. Apply a moderate amount of good quality pipe compound
(do not use Teflon tape) to pipe only, leaving two end
threads bare.
Note: The gas train and controls assembly provided on this
unit have been tested under the applicable American National
Standard to meet minimum safety and performance criteria
such as safe lighting, combustion and safety shutdown
operation.
7. Remove seal over gas inlet to unit.
8. Connect gas pipe to inlet of unit. Use wrench to support
gas manifold on the unit.
Figure 19 shows a typical gas train.
9. For L.P. gas, consult your L.P. gas supplier for expert
installation.
TABLE-G
Fittings to Equivalent Straight Pipe
10. Ensure that all air is properly bled from the gas line before
starting the ignition sequence. Start up without properly
bleeding air from the gas line may require multiple reset
functions of the ignition control module to achieve proper
ignition.
Diameter Pipe (inches)
3/4
1
1 1/4
1 1/2
2
3
4
5
Equivalent Length of Straight Pipe (feet)

2
WARNING: Do not have any open flame in
proximity to the gas line when bleeding air from
the gas line. Gas may be present.
2
3
4
TABLE-F
17
5
10
14
20
Hydronic Heating Boilers and
Domestic Water Heaters
not required to have vent or relief lines piped to the outdoors.
The termination of the vent limited opening on the
combination gas valve/regulator complies with the safety code
requirements of CSD-1, CF-190(a) as shipped from the
appliance manufacturer without the installation of additional
vent lines.
INSTALLATION
Continued
Water heater models do not have downstream test valves, but
the rest of the gas train is represented by Figure 19.
Combination Gas Valves
Checking Gas Supply Pressure
These units fire in up to 2 stages of burner input. Each stage of
burner operation has a combination gas valve or series of gas
valves to cycle the gas supply on and off and regulate gas to the
burners. Each combination valve consists of a gas regulator and
two valve seats to meet the requirements for redundant gas
valves. The valve has a gas control knob that must remain in the
open position at all times when the unit is in service. The gas
control valve has pressure taps located on the inlet and discharge
sides of the valve. Manifold pressure is adjusted using the
regulator located on the valve. A manifold gas pressure tap for
each burner stage is located on the discharge side of the valve.
Use the following procedure to check gas supply pressure.
1. Turn the main power switch to the "OFF" position.
2. Turn gas valve knobs to the "OFF" position.
3. Shut off gas supply at the field-installed manual gas cock
in the gas piping to the unit. If fuel supply is L.P. gas, shut
off gas supply at the tank.
4. Remove the 1/8" hex plug, located on “inlet” side of the
gas valve. You may also use a tapping on the field-installed
main manual gas cock or gas piping. Install a fitting in the
inlet pressure tapping suitable to connect to a manometer
or magnahelic gauge. Range of scale should be 14" w.c. or
greater to check inlet pressure.
The manifold pressure is preset at the factory and adjustment
is not usually required. If you must adjust regulator pressure,
follow the instructions under Gas Manifold Pressure
Adjustment, page 19.
5. Turn on gas supply at the manual gas cock, turn on L.P. gas
at tank if required.
6. Turn the power switch to the “ON” position.
Venting of Combination Gas Valves
7. Turn the gas valve knobs to the “ON” position. Set the
electronic temperature control or thermostat to call for
heat.
The combination gas valve/regulator used on all units is
equipped with an integral vent limiting orifice per ANSI
Z21.78. The vent limiter ensures that the volume of gas
emitted from the valve does not exceed the maximum safe
leakage rate allowed by agency requirements. Combination
gas valve/regulators equipped with integral vent limiters are
8. Observe the gas supply pressure as all burners are firing.
Ensure that inlet pressure is within the specified range. See
Connecting To Gas Supply, page 16 for minimum and
maximum gas supply pressures.
TABLE - H
Multiple Unit Installations Gas Supply Pipe Sizing
Nominal Iron
Pipe Size,
(Inches)
Length of Pipe In Straight Feet
10
20
30
40
50
60
70
80
90
100
125
150
175
200
3/4"
369
256
205
174
155
141
128
121
113
106
95
86
79
74
1"
697
477
384
328
292
267
246
226
210
200
179
164
149
138
1 1/4"
1,400
974
789
677
595
543
502
472
441
410
369
333
308
287
1 1/2"
2,150
1,500
1,210
1,020
923
830
769
707
666
636
564
513
472
441
2"
4,100
2,820
2,260
1,950
1,720
1,560
1,440
1,330
1,250 1,180
1,100
974
871
820
2-1/2"
6,460
4,460
3,610
3,100
2,720
2,460
2,310
2,100
2,000 1,900
1,700
1,540 1,400 1,300
3"
11,200
7,900
6,400
5,400
4,870
4,410
4,000
3,800
3,540 3,300
3,000
2,720 2,500 2,340
4"
23,500
16,100
13,100 11,100
10,000
9,000
8,300
7,690
7,380 6,870
6,150
5,640 5,130 4,720
Maximum capacity of pipe in thousands of BTU’s per hour for gas pressures of 14 Inches Water Column (0.5 PSIG) or less and a total system
pressure drop of 0.5 Inch Water Column (Based on NAT GAS, 1025 BTU’s per Cubic Foot of Gas and 0.60 Specific Gravity).
18
Installation and
Service Manual
9. If gas pressure is out of range, contact your gas utility, gas
supplier, qualified installer or service agency to determine
the necessary steps to provide proper gas pressure to the
control.
10. If gas supply pressure is within normal range, remove the
gas manometer and replace the pressure tap fittings in the
gas control as indicated in the following steps.
11. Turn the power switch to the “OFF” position.
4
12. Turn gas valve knob to the “OFF” position.
3
13. Shut off gas supply at the manual gas cock in the gas
piping to the unit. If fuel supply is L.P. gas, shut off gas
supply at the tank.
2
INLET
1/8" HEX INLET
PRESSURE TAP
1
0
14. Remove the manometer and related fittings from the
“inlet” side of the gas valve, replace 1/8" hex plug in the
gas valve and tighten.
1
2
3
15. Turn on the gas supply at the manual valve, turn on L.P.
gas at the tank if required.
4
MANOMETER
16. Turn the power switch to the “ON” position.
17. Turn the gas valve knob to the “ON” position.
GAS
VALVE
CONTROL
KNOB
18. Set the electronic temperature control or thermostat to call
for heat.

WARNING: After completing any testing
on the gas system, leak test all gas connections.
Apply a soap/water solution to all gas
connections while main burners are operating.
Bubbles forming indicate a leak. Repair all leaks
at once. Do not operate this unit with a leak in the
gas train, valves or related piping.
OUTLET
Figure 20 - Measuring Gas Supply Pressure at
Combination Gas Valve
Gas Manifold Pressure Adjustment
IMPORTANT: The gas valves are referenced to
the fan pressurized chamber by a hose
connected from the vent of the gas valve
regulator to the chamber pressure tap located on
the front inside portion of the jacket. Reference
the drawings in this section for component and
connection points for pressure measurement.
The referenced chamber pressure must be
subtracted from the manifold pressure to obtain
actual net manifold pressure for normal
operation. A manometer or magnahelic gauge
legible in 0.1" increments up to 10 inches w.c. is
required to check and adjust the manifold
pressure. The regulator cover screw on the gas
valve must be in place and tight for the unit to
operate properly.
Check burner performance by cycling the system while you
observe burner response. Burners should ignite promptly.
Flame pattern should be stable, see Burner Flames, page 40.
Turn the system off and allow burners to cool, then cycle
burners again to ensure proper ignition and flame
characteristics.
1. Remove screws that fasten the control panel access door
and remove the door.
19
Hydronic Heating Boilers and
Domestic Water Heaters
12. If adjustment is necessary, remove the regulator cover screw
on the gas valve. Note: If the gas valve under adjustment is
located on a manifold assembly monitored by an igniter, the
unit may shut down and recycle when the regulator cover
screw is removed. This is normal.
INSTALLATION
Continued
13. Turn the regulator adjustment screw “clockwise” to raise the
regulator gas pressure. Turn the regulator adjustment screw
“counterclockwise” to lower the regulator gas pressure.
14. Replace the regulator cover screw and make sure it is tight
for proper operation.
15. Read the value on the manometer/magnahelic and compare it
to the values in TABLE-I.
16. Repeat this adjustment procedure for each gas valve as
necessary to adjust to the proper manifold gas pressure.
17. Remove hoses, replace and tighten plugs and caps when
complete.
18. Replace top front upper jacket access panels and control
panel door in reverse order.
19. If proper ignition and burner operation is not achieved after
checking gas supply pressure, see Cleaning and
Maintenance, page 41 for Combustion Air Fan Adjustment.
Follow the procedure to adjust the combustion air fans as
necessary.
Figure 21 - Measuring Manifold Gas Pressure
2. Turn the power switch located in the lower left corner
behind the control panel access door to the “O” or “OFF”
position.
TABLE - I
NET MANIFOLD PRESSURE
3. Remove the top front jacket access panels to access the gas
valve(s).
4. Locate the reference hose on the first gas valve which goes
from the vent fitting on the gas valve to the barbed fitting
on the deck of the unit (see Figure 21).
Regulator Pressure Less
Front Chamber Pressure
5. Remove the flexible cap from the barbed fitting on the
"tee" located in this line and hook one side of the
manometer, or (-) side of a magnahelic gauge, to this "tee".
Retain this cap for future use.
Nat. Gas (495,000 - 745,000 Btu/hr)
Nat. Gas (985,000 - 2,065,000 Btu/hr)
LP Gas (495,000 - 2,065,000 Btu/hr)
6. Remove the 1/8" hex plug from the manifold pressure tap
on the gas valve (see Figure 21). Retain plug for future use.
1.8" w.c.
1.2" w.c.
4.6" w.c.
TABLE-H
7. Install a fitting in this tap that is suitable for connection of
a hose to a manometer, or (+) side of a magnahelic gauge
(see Figure 21).
8. Turn the power switch to the “I” or “ON” position.
CONNECTING TO WATER
SUPPLY
9. Push the reset button(s) for the ignition control(s), if
necessary.
Inlet and Outlet Connections
10. Set the temperature control to call for heat (see Setting
Temperature Control, page 29).
For ease of service, install unions on the water inlet and water
outlet of the unit. The connection to the unit marked “Inlet” on
the header should be used for return from the system. The
connection on the header marked “Outlet” is to be connected
to the supply side of the system.
11. Once the unit is firing, the manometer/magnahelic will
reflect the net manifold gas pressure. Compare this reading to
the respective value in TABLE-I for Natural Gas or Propane
Gas.
20
Installation and
Service Manual
Low Water Cutoff
(If Equipped)
If installing this unit above radiation level, you must install a
low water cut-off device at the time of appliance installation.
Electronic or float type low water cutoff controls are available
as a factory supplied option on all units. Inspect the low water
cutoff every six months, including flushing of float types. The
low water cutoff control is located on the control panel directly
behind the control panel cover.
The reset and test buttons (if equipped) are located on the
control panel.
CONNECTING TO
ELECTRICAL SUPPLY
Figure 22 - Water Connections
This unit is wired for 120 VAC service. The unit, when
installed, must be electrically grounded in accordance with the
requirements of the authority having jurisdiction or in the
absence of such requirements, with the latest edition of the
National Electrical Code ANSI/NFPA No. 70. When the unit is
installed in Canada, it must conform to the CAE C22.1,
Canadian Electrical Code, Part 1 and/or local Electrical Codes.
Relief Valve
This unit is supplied with a relief valve(s) sized in accordance
with ASME Boiler and Pressure Vessel Code, Section IV
("Heating Boilers"). The relief valve(s) is installed in the
vertical position and mounted in the hot water outlet. Place no
other valve between the relief valve and the unit. To prevent
water damage, pipe the discharge from the relief valve to a
suitable floor drain for disposal when relief occurs. Do not
install any reducing couplings or other restrictions in the
discharge line. The discharge line will allow complete drainage
of the valve and line. Manually operate the relief valves at least
once a year.

CAUTION:
discharge water.
Avoid
contact
with
1. Use only Type-T wire [63°F (35°C) rise] on all wiring
between the unit and field-installed devices.
2. Enclose line voltage wire exterior to the unit in approved
conduit or approved metal-clad cable.
3. The pump must run continuously when the unit is being
fired (hot water heating boilers must use the optional pump
delay if the pump is to be cycled. See Freeze Protection,
page 7 when cycling the pump). Water heaters use the
pump delay as standard in accordance with ASHRAE 90.1
requirements.
hot
4. To avoid serious damage, do not energize the unit until the
system is filled with water.
Water Flow Switch
A water flow switch is factory installed. The flow switch is
wired in series with the 24 VAC safety control circuit at the
units terminal strip. This wiring connection installs the flow
switch in the 24 VAC safety circuit to prove water flow before
main burner ignition. The factory supplied flow switch is
installed in the outlet side of the front header. These units
require a minimum flow of 26 GPM to make the flow switch
and start burner operation. Ensure that the pump installed on
the unit will supply adequate flow to make the flow switch
contacts and operate the unit. A water flow switch meets most
code requirements for a low water cut off device on appliances
requiring forced circulation for operation.
5. Provide the unit with proper overload protection.
21
Hydronic Heating Boilers and
Domestic Water Heaters
INSTALLATION
IMPORTANT: Do not block access to the
electrical cover plate when installing electrical
conduit.
Continued
TABLE - J
Nominal AMP Draw Data
TABLE
Btu/Hr
Input
AMP Draw Data
External EMS Connection to Terminal
Strip for Stage Firing Control of Burners
Approximate
Controls
Fan
Total Amps
495,000
4.6
3.4
8.0
645,000
4.6
3.4
8.0
745,000
4.6
3.4
8.0
985,000
4.6
3.4
8.0
1,255,000
4.6
3.4
8.0
1,435,000
4.6
3.8
8.4
1,795,000
4.6
3.8
8.4
2,065,000
4.6
3.8
8.4
This unit is equipped with a factory installed terminal strip for
connection of an energy management system (EMS) to the
burner stages. The EMS terminal strip is located in the unit's
junction box. Ensure that all wiring used for connection to this
terminal strip is properly sized per the recommendations in
TABLE-L. When connecting an EMS to this terminal strip to
sequence on each stage of burner operation, the unit's internal
thermostat or electronic sequencer should be set as an
additional high limit control. This will prevent problems
between the set points of the EMS and the boiler's internal
controller.
Terminal Strip Connection Options
(Models 985,000 - 2,065,000 Btu/hr Only)
Figure 24A shows the position of jumpers as shipped from the
factory for stand-alone operation of boilers or water heaters.
Figure 24B shows connections to the terminal strip for Remote
ON/OFF control of the boiler or water heater. The 1C-1NO
jumper must be removed when making these wiring
connections. This remote ON/OFF control will provide an
Enable/Disable signal to the unit and allow the unit to operate
based on the stage set points, until the remote ON/OFF signal
is cancelled.
Figure 24C shows the connections necessary to operate the
unit as a two-stage (High/Low Fire) boiler or water heater from
an Energy Management System (EMS). The actual set point
temperatures are controlled by the EMS. The High Fire Offset
on the electronic temperature control in the unit must be set to
zero and the set point must be set to a value which will function
as an upper limit for proper operation under this two-stage
control from an EMS.
Figure 23A - Models 495,000 - 745,000 Btu/hr Control
Panel Component Location Drawing
Figure 24D shows the Continuous and Intermittent terminals.
External safety devices connected to these terminals will
function to protect the unit. Devices connected to the
Intermittent terminals (B1 and B2) are monitored only when
there is an active Call for Heat. Devices connected to the
Continuous terminals (A1 and A2) are monitored continuously
and will activate an alarm (if the unit is equipped with the
alarm option) anytime the safety device senses an abnormal
condition. An additional wire may be field-installed from these
safety devices to terminals A3 or B3 (as appropriate) to
activate an alarm (if the unit is equipped with the alarm
option).
Figure 23B - Models 985,000 - 2,065,000 Btu/hr Control
Panel Component Location Drawing
22
Installation and
Service Manual
BOILER SYSTEM PIPING
The drawings in this section show typical boiler piping
installations. Before beginning the installation, consult local
codes for specific plumbing requirements. Be sure to provide
unions and valves at the boiler inlet and outlet so it can be
isolated for service. You must install an air separation device in
the installation piping to eliminate trapped air in the system.
Locate a system air vent at the highest point in the system. The
system must also have a properly sized expansion tank
installed. Typically, an air charged diaphragm-type
compression tank is used. You must install the expansion tank
close to the boiler and on the suction side of the system pump
to ensure proper operation.
Figure 24A - Stand Alone Operation - Models 985,000 2,065,000 Btu/hr Only

CAUTION: This boiler system should not
be operated at less than 12 PSIG.
Provide suitable hangers or floor stands to support hot water
piping. The boiler alone should not support hot water piping.
Copper pipe systems are subject to considerable expansion and
contraction. Rigid pipe hangers could allow the pipe to slide in
the hanger resulting in noise transmitted into the system. Use
padding on rigid hangers installed with a copper system. Pipe
the boiler pressure relief valve to a suitable floor drain. See the
relief valve section in this manual.
Figure 24B - Remote On/Off Boiler or Water Heater Models 985,000 - 2,065,000 Btu/hr Only

CAUTION: A leak in a boiler "system" will
cause the "system" to intake fresh water
constantly, which will cause the tubes to
accumulate a lime/scale build up. This will cause
a non-warrantable failure.
General Plumbing Rules
1. Check all local codes.
2. For serviceability of boiler, always install unions.
Figure 24C - Two-Stage (High/Low Fire) Boiler or Water
Heater - Models 985,000 - 2,065,000 Btu/hr Only
3. Always pipe the pressure relief valve to an open drain.
4. Locate system air vents at the highest point of system.
5. Expansion tank must be installed near the boiler and on the
suction side of the pump.
6. Support all water piping.
Water Connections: Heating
Boilers Only
Inlet and outlet water connections on models 495,000 745,000 Btu/hr have 2" NPT and on models 985,000 2,065,000 Btu/hr the inlet and outlet connections are
2 1/2" NPT.
Note: Field-installed reducing bushings may decrease flow
resulting in boiler noise or flashing to steam.
Figure 24D - Field-Installed Safety Devices - Models
985,000 - 2,065,000 Btu/hr Only
23
Hydronic Heating Boilers and
Domestic Water Heaters
Circulator Pump Specifications
INSTALLATION
1. Maximum operating pressure for pump must exceed
system operating pressure.
2. Maximum water temperature should not exceed nameplate
rating.
Continued
Circulator Pump Requirements
This is a low mass, high efficiency hot water boiler which must
have adequate flow for quiet, efficient operation. Pump
selection is critical to achieve proper operation. A pump should
be selected to achieve proper system design water temperature
rise. Two heat exchanger head-loss charts (Figure 25A & 25B)
are provided to assist in proper pump selection. Also provided
is a System Temperature Rise Chart (TABLE-K). This table
provides GPM and boiler head-loss at various temperature
rises for each boiler based on Btu/hr input. Temperature rise is
the difference in boiler inlet temperature and boiler outlet
temperature while the boiler is firing.
3. Cast iron circulators may be used for closed loop systems.
4. A properly sized expansion tank must be installed near the
boiler and on the suction side of the pump.
Circulator Pump Operation
(Heating Boilers Only)
The boiler pump should run continuously unless the boiler is
provided with the optional pump delay control system. This
optional pump control system is available as a factory-installed
option. External wire leads are furnished with this option to
allow the power supply for the pump to be switched across the
normally open contacts of the relay, allowing the control relay
to cycle the pump on each call for heat. The field installed
boiler pump (using the optional factory supplied pump control
system) must not exceed 10 AMPS at 120VAC. As shipped
from the factory, the optional control system is set to cycle the
boiler pump on at each call for heat before the burners fire and
run the pump for a 30 second period after the thermostat is
satisfied. This will remove any residual heat from the
combustion chamber before turning the pump off. See Wiring
Diagrams, page 47.
Example: The boiler inlet temperature is 160°F (71°C) and the
boiler outlet temperature is 180°F (82°C), this means that there
is a 20°F (11°C) temperature rise across the boiler.
Heat Exchanger Pressure Drop Chart
Pump Installation and Maintenance
For installation and maintenance information on the circulator
pump, refer to pump manufacturers instructions included in the
instruction package.
Primary/Secondary Boiler Piping
Boiler installations with a primary/secondary piping system as
shown in Figure 26 are recommended. This type of system
uses a dedicated pump to supply flow to the boiler only. This
secondary pump is sized based on desired boiler flow rate,
boiler head loss and head loss in the secondary system piping
only. A properly-sized system pump provides adequate flow to
carry the heated boiler water to radiation, air over coils, etc.
The points of connection to the primary system should be a
maximum of 12" (or 4 pipe diameters) apart to ensure
connection at a point of zero pressure drop in the primary
system. Multiple boilers may also be installed with a
primary/secondary manifold system as shown in Figure 27.
The multiple boilers are connected to the manifold in reverse
return to assist in balancing flow to multiple boilers.
Figure 25A - Pressure Drop Chart_Models 495,000 745,000 Btu/hr

CAUTION: DO NOT allow the flow in the
primary loop to drop lower than the flow in the
secondary loop at any time during boiler
operation. Improper operation of the boiler(s)
and possible tripping of the high limits and relief
valves may occur.
Figure 25B - Pressure Drop Chart_Models 985,000 2,065,000 Btu/hr
24
Installation and
Service Manual
The installer must ensure that the boiler has adequate flow
without excessive temperature rise. Low system flow can
result in overheating of the boiler water which can cause short
burner ON cycles, system noise and in extreme cases, a
knocking flash to steam. These conditions indicate the need to
increase boiler flow by installation of a larger circulator pump
or the installation of a system bypass. System noise may also
indicate an oversized boiler.
temperature protection valve (LTV) that is factory preset to
maintain 140°F inlet water to the boiler regardless of the
system return water temperature. See Table K for available
valve kits.
Table - K
LTV Valve Kits
Input
Btu/hr
 CAUTION: At no time should the system
pressure be less than 12 PSIG.
Figure 26 - Primary/Secondary Piping of a Single Boiler
EXPANSION TANK
PRV
LWCO
(OPTIONAL)
MAKE-UP
WATER
TO SYSTEM
SYSTEM PUMP
12" OR 4 PIPE
DIAMETERS
AIR SEPARATOR
FROM SYSTEM
LTV Valve Kit
495,000 - 745,000
VAL3048
985,000 - 2,065,000
VAL3047
Be sure to install the LTV valve per the piping diagrams
included with the kits. Alternatively, a bypass as shown in
FIG. 28 may be piped into the system. This piping is like a
primary/secondary boiler installation with a bypass in the
secondary boiler piping. Inlet water temperatures below 140°F
(60°C) can excessively cool the products of combustion
resulting in condensation on the heat exchanger and in the flue.
Condensation can cause operational problems, bad
combustion, sooting, flue gas spillage and reduced service life
of the vent system and related components. The bypass allows
part of the boiler discharge water to be mixed with the cooler
boiler return water to increase the boiler inlet temperature
above 140°F (60°C). This should prevent the products of
combustion from condensing in most installations. The bypass
should be fully sized with a balancing valve to allow for proper
adjustment. A valve must also be provided on the boiler
discharge, after the bypass. Closing this discharge valve forces
water through the bypass. Start boiler adjustment with the
bypass valve in the full open position and the boiler discharge
valve half open. A small amount of the higher temperature
boiler discharge water is mixed with the system water to
maintain the desired lower system temperature. A remote low
temperature range operator is recommended to control the
boiler operation based on the lower system temperature. (See
Terminal Strip Connection Options starting on
page 22).
Radiant Floor and Snow Melt
Heating Systems
SECONDARY
BOILER PUMP
This type of heating boiler application operates in a low
temperature range which requires a boiler bypass as described
under Low Temperature Bypass Requirements. A non-metallic
rubber or plastic tubing installed in a radiant (in floor) system
must have an oxygen barrier to prevent oxygen from entering
the system through the walls of the installed tubing. Excessive
oxygen absorption into the system will result in an accelerated
rate of corrosion causing a sludge buildup. This excessive
corrosion will also damage the boiler and system components.
Figure 27 - Primary/Secondary Piping of Multiple Boilers
Low Temperature Return Water
Systems
Any non-condensing boiler and venting system will develop
operational problems when exposed to inlet water
temperatures below 140°F.
Lochinvar offers a low
25
Hydronic Heating Boilers and
Domestic Water Heaters
Installation with a Chilled Water
System
INSTALLATION
Continued
Pipe refrigeration systems in parallel. Install duct coil
downstream at cooling coil. Where the hot water heating boiler
is connected to a heating coil located in the air handling units
which may be exposed to refrigeration air circulation, the
boiler piping system must be equipped with flow control
valves or other automatic means to prevent gravity circulation
of the boiler water during the cooling cycle. The coil must be
vented at the high point and hot water from the boiler must
enter the coil at this point. Due to the fast heating capacity of
the boiler, it is not necessary to provide a ductstat to delay
circulator operation. Also, omit thermostat flow checks as the
boiler is cold when heating thermostat is satisfied. This
provides greater economy over maintaining standby heat (see
Figure 29).
Sludge formed as the result of excessive oxygen in the system
can restrict water flow resulting in a premature boiler failure.
Any boiler damage due to excessive oxygenation is nonwarrantable.
EXPANSION
TANK
HEATING AND
COOLING COIL
LOW WATER
FLOW SWITCH
PUMP
Figure 28 - Boiler with Low Temperature Bypass Piping
OUT
IN
GAS
SUPPLY
CHILLER
WATER
SUPPLY
BOILER
Figure 29 - Installation with a Chilled Water System
TABLE - L
System Temperature Rise Chart Based on Btu/hr Input
System Temperature Risased on Btu/hr Input
T
T
T
T
10ºF
20ºF
30ºF
40ºF
GPM FT. HD GPM FT.HD
GPM FT.HD
T
50ºF
T
60ºF
Input
Output
GPM FT.HD GPM FT.HD GPM FT.HD
495,000
400,950
80+
*
40
4.0
27
1.6
20
0.7
16
0.6
13
0.6
645,000
522,450
129+
*
52
5.1
35
3.0
26
1.6
21
0.8
17
0.6
745,000
603,450
149+
*
60
*
40
4.0
30
2.3
24
1.2
20
0.7
985,000
831,600
197+
*
80
5.2
53
2.4
40
1.4
32
1.0
27
0.8
1,255,000
1,058,400
251+
*
102+
*
68
4.3
51
2.5
41
1.6
34
1.1
1,435,000
1,209,000
288+
*
116+
*
78
6.0
58
3.7
47
2.2
39
1.7
1,795,000
1,512,000
360+
*
146+
*
97+
*
73
6.2
58
4.2
49
2.4
2,065,000
1,738,800
414+
*
168+
*
112+
*
84
8.7
67
6.0
56
4.5
+ These flow rates exceed recommended flow rates of boiler. If these system temperature rises are used, an external piping by-pass must be installed.
* These foot head calculations exceed the maximum allowable flow rate of the boiler. Requires Cupro-Nickel heat exchanger.
26
Installation and
Service Manual
Boiler Flow Rate

CAUTION: The maximum flow rate for
models 495,000 - 745,000 Btu/hr is 60 GPM and
90 GPM on 985,000 - 2,065,000 models. Do not
exceed the maximum flow rate of the heating
boiler.
If higher flow rates are required through the boiler,
an optional Cupro-Nickel heat exchanger is
available. When using a Cupro-Nickel heat
exchanger, GPM can be increased by 30 percent.
Consult the factory for specific application
requirements.
The heat exchanger is generally capable of operating within
the design flow rates of the building heating system. Should
the flow rate exceed the maximum allowable flow rate through
the boiler an external bypass must be installed. The bypass
should be fully sized with a balancing valve to allow for proper
adjustment of flow. Flow rate can be determined by measuring
the temperature rise through the boiler.
Figure 30 - Boiler Bypass Piping for High Flow Systems
Filling the System
All air must be purged from the system for proper operation.
An air scoop and air vent must be located close to the boiler
outlet and there should be a minimum distance between the
cold water feed and the system purge valve.
Boiler Bypass Requirements
The installer must ensure that the boiler is supplied with
adequate flow without excessive temperature rise. It is
recommended that this boiler be installed with a bypass in the
piping if the maximum recommended flow rate is exceeded.
The bypass will help to ensure that the boiler can be supplied
with adequate water flow. Flow rates exceeding the maximum
recommended flow will result in erosion of the boiler tubes. A
typical bypass with a valve is shown in Figure 30 will allow
control of boiler flow.
1. Close all drain cocks and air vents.
2. Open the makeup water valve and slowly fill the system.
3. If a makeup water pump is employed, adjust the pressure
to provide a minimum of 12 psi at the highest point in the
system. If a pressure regulator is also installed in the line,
it should be adjusted to the same pressure.
4. Close all valves. Purge one circuit at a time as follows:
Temperature/Pressure Gauge
This boiler is equipped with a dial type temperature/pressure
gauge. This gauge is factory installed in the outlet side of the
heat exchanger. The gauge has one scale to read system
pressure and a separate scale to read water temperature in
degrees, Fahrenheit.
A.
Open one circuit drain valve and let the water drain
for at least five minutes. Ensure that there are no air
bubbles visible in the water stream before closing
the drain valve.
B.
Repeat this procedure for each circuit.
5. Open all valves after all circuits have been purged. Make
sure there are no system leaks.

CAUTION: Do not use petroleum based
stop leak products. All system leaks must be
repaired. The constant addition of make-up water
can cause damage to the boiler heat exchanger
due to scale accumulation. Scale reduces flow
and heat transfer, causing overheating of the
heat exchanger.
6. Run the system circulating pump for a minimum of 30
minutes with the boiler turned off.
7. Open all strainers in the system and check for debris.
27
Hydronic Heating Boilers and
Domestic Water Heaters
INSTALLATION
OPERATION
Continued
FOR YOUR SAFETY READ
BEFORE OPERATING
8. Recheck all air vents as described in step 4.

9. Inspect the liquid level in the expansion tank. The system must
be full and under normal operating pressure to ensure proper
water level in the expansion tank. Ensure that diaphragm type
expansion tanks are properly charged and not water logged.
WARNING: If you do not follow these
instructions exactly, a fire or explosion may
result causing property damage, personal injury
or loss of life.
10. Start the boiler according to the operating instructions in this
manual. Operate the system, including the pump, boiler and
radiation units, for one hour.
A. This appliance does not have a pilot. It is equipped with an
ignition device which automatically lights the burner. Do not
try to light the burner by hand.
B. BEFORE OPERATING, smell around the appliance area
for gas. Be sure to smell next to the floor because some gas
is heavier than air and will settle to the floor.
11. Recheck the water level in the expansion tank. If it exceeds
half the tank volume, open the tank to reduce the water level.
Recheck pressure charge on diaphragm type tanks.
12. Shut down the entire system and vent all radiation units and
high points in the system.
WHAT TO DO IF YOU SMELL GAS
• 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
neighbors phone.
• Follow the gas supplier's instructions.
• If you cannot reach your gas supplier, call the
fire department.
13. Close the water makeup valve and check the strainer and
pressure reducing valve for sediment or debris. Reopen the
water makeup valve.
14. Verify system pressure with the boiler pressure gauge before
beginning regular operation.
15. Within three days of startup, recheck and bleed all air vents
and the expansion tank using these instructions.
C. Use only your hand to turn the gas control lever. Never use
tools. If the lever will not turn by hand, don't try to repair it,
call a qualified service technician. Force or attempted repair
may result in a fire or explosion.
D. Do not use this boiler if any part has been under water.
Immediately call a qualified service technician to replace the
boiler. The possible damage to a flooded boiler can be
extensive and present numerous safety hazards. Any
appliance that has been under water must be replaced.
WATER TREATMENT
In hard water areas, water treatment should be used to reduce
the introduction of minerals to the system. Minerals in the
water can collect in the heat exchanger tubes and cause noise
on operation. Excessive build up of minerals in the heat
exchanger can cause a non-warrantable failure.
Lighting Instructions
1. STOP! Read the safety information.
2. Set the temperature control to the desired settings (see
Setting Temperature Control, page 29).
3. Loosen the knurled knob at the bottom of the control panel
cover (see Figure 31).
4. Grasp the bottom of the control panel cover and pull out
and down.
5. Locate the ON/OFF switch inside the control area. The
switch is located to the left of the control panel (see
Figure 32).
6. Turn the power switch to the “OFF” position.
7. This unit is equipped with an ignition device which
automatically lights the burners. Do not try to light the
burners by hand.
28
Installation and
Service Manual
To Turn Off Gas To Appliance
1. Remove the control panel cover to access control panel.
2. Turn power switch to "OFF" position.
3. Turn the manual gas cock clockwise to the "OFF" position.

WARNING: Should overheating occur or
the gas fail to shut off, turn off the manual gas
control valve to the unit.
Figure 31 - Control Panel Cover
FIG. 32
NO INTERNAL OR EXTERNAL CHANGES
WITHOUT WRITTEN APPROVAL BY
LOCHINVAR CORPORATION ENGINEERING.
Figure 33 - Combination Gas Valve
SETTING TEMPERATURE
CONTROL
Note: The temperature controller is preset at the factory with
test settings. You may need to adjust the settings to meet your
specific needs.

WARNING: Return water temperatures
must not be less than 140°F. If lower return water
temperatures are required, follow the instructions
for Low Temperature Return Water Systems on
page 25.
Figure 32 - ON/OFF Switch
8. Turn the manual gas cock clockwise to the “OFF” position.
9. Wait five (5) minutes to clear out any gas. If you smell gas,
STOP! Follow “B” in the safety information. If you do not
smell gas, go on to the next step.
10. Turn the manual gas cock counterclockwise to the “ON”
position.
Locating Temperature Control
The temperature control is located behind the combustion air
inlet panel on the left front of the unit (see Figure 34). Follow
the steps below to access the temperature control.
11. Turn the power switch to the “ON” position.
12. Reinstall the control panel cover. Tighten the knurled knob
at the bottom of the control panel cover.
1. Loosen the knurled knob at the bottom of the control panel
cover.
13. If the unit will not operate, follow the instructions “To
Turn Off Gas To Appliance” and call your service
technician or gas supplier.
2. Pull the bottom of the panel out and down to remove.
29
Hydronic Heating Boilers and
Domestic Water Heaters
OPERATION
Continued
Figure 35 - Temperature Control Setting Knobs
TABLE-L
TABLE - M
Maximum Set Point Determination
Figure 34 - Locating Temperature Control
Maximum
Setpoint
n
Temperature Control Settings
There are three setting knobs on the temperature control unless
your unit is specified as a boiler only with an outdoor air reset
option. If your unit is a boiler only with an outdoor air reset
option, there are additional controls for this option. They are
explained under Outdoor Air Reset Option, page 31.
OJ1
OJ2
Max.
Set Point
Connected
Connected
230°F
Cut
Connected
190°F
Connected
Cut
200°F
Cut
Cut
160°F
The three setting knobs on the temperature control are for Set
Point, Differential, and High-Fire Offset (see Figure 35).
Note: Anytime that OJ1 is the only jumper cut, a new
overlay is required under the Set Point knob on the
temperature controller because the scale has changed to a
maximum of 190°F.
Maximum Set Point Determination
The maximum set point for the control is factory set. Boilers
are set to 230°F max., water heaters are set to 190°F max., and
specialty state and local codes to 200°F.
Anytime the OJ2 jumper is cut (with or without OJ1), a
new overlay is required under the Set Point knob on the
temperature controller because the scale has changed to a
maximum of 200°F.
These maximum set points are established by not
cutting/cutting the OJ1 and OJ2 jumpers located on the right
side of the temperature controller (see Figure 35). The
maximum set point is determined as shown in TABLE-M.
Set Point
The Set Point knob specifies the target water temperature in
degrees, Fahrenheit. After the water temperature reaches the
set point, the temperature control shuts off the burners.
Differential
The Differential specifies the number of degrees below the set
point that the control will allow the water temperature to drop
before it brings the unit back on again.
30
Installation and
Service Manual
CN8
45
CN1
65
The High-Fire knob specifies the number of degrees below set
point that the High-Fire stage shuts down. At that point, the
unit will continue to operate at the Low-Fire stage until the set
point is reached.
40
70
SHUTDOWN
55
50
60
45
O.A. SENSOR
ON ENABLE
CN3
OJ1
CN4
SW1
VR3
W1
CN2
60
C10
D4
The temperature control operates a two-stage firing system.
The two stages are High-Fire and Low-Fire. High-Fire
operates all burners while Low-Fire operates approximately
one-half of the burners.
55
65
DISABLE
O.A. SHUTDOWN
CN5
0.9 1.01.1
1.2
0.8
1.3
0.7
OJ2
C9
50
CN6
J4
(c)2002 L.C.
CN7
R6
R4
C7
High-Fire Offset
W3
R8
1.4
0.6
VR2
0.5
1.5
40
70
W1
W2
CN1
RATIO
O.A. MAX.
CN9
160
9 10 11
10
200
12
8
140
15
5
13
7
220 6
14
120
5 VR2 15
(F-)0 VR3 20
240
DIFFERENTIAL
HIGH-FIRE
OFF
TST2314
OFFSET
SETPOINT
VR1
R15
R16
The High-Fire offset knob has settings between 0°F and 20°F.
If set at 0°F, the High-Fire offset is disabled and the unit will
operate at the High-Fire stage until the set point is reached and
the temperature control shuts the unit off.
When the High-Fire offset knob is set to 0 or 1, the unit will
light at Low Fire and operate for approximately 10 seconds
before the High-Fire stage actuates. When set to 2 or above,
the unit will operate at Low Fire for 2 minutes before the High
Fire stage actuates.
Figure 36 - Optional Outdoor Air Reset Control
Outdoor Air Reset Option
For boilers ordered with the Outdoor Air Reset option, there is
an additional control (see Figure 36). There are three setting
knobs for Shutdown, Outdoor Air Max., and Ratio. There is
also a switch to turn the outdoor air sensor On or Off. An O.A.
Sensor is also included.
Shutdown
The Shutdown knob specifies the outdoor air lockout
temperature at which the control would prevent the unit from
operating. This feature can be enabled/disabled with the O.A.
Shutdown switch.
Outdoor Air Max (O.A. Max)
The O. A. Max knob allows a reset up to the maximum outdoor
air temperature specified by this knob setting. When the
outdoor air temperature is above the specified setting, the unit
will not function in the O.A. Reset Mode, but will continue to
run at the selected set point temperature.
Note that the set point knob will now indicate the “minimum”
boiler temperature. Target temperature is determined by the
ratio and outdoor air temperature below the O.A. Max setting.
Ratio
The Ratio knob allows the control over the reset ratio to be
used during Outdoor Air Reset. The allowable ratios are as low
as 0.5:1 or as high as 1.5:1.
Selecting the 0.5:1 ratio will increase the set point 0.5°F for
every 1.0°F drop in outdoor air temperature up to the
maximum set point temperature.
Selecting the 1.5:1 ratio will increase the set point 1.5°F for
every 1.0°F drop in outdoor air temperature up to the
maximum set point temperature.
See Figure 37 for an outdoor air reset chart example.
31
Hydronic Heating Boilers and
Domestic Water Heaters
OPERATION
Boiler Application
Continued
Standard boiler units are shipped with two sensors; the inlet
water temperature sensor and the multi-purpose temperature
sensor. The multi-purpose sensor should be used as a system
sensor. Boilers with the outdoor air reset option also have an
outside air temperature sensor.
Temperature Control Sensors
This is a two-stage temperature control that controls the burner
ignition, pump, and alarm functions. This temperature
controller can measure up to three different sensor inputs,
depending upon how the unit is set up. They are as follows:
1. Inlet Water Temperature Sensor
2. Multi-Purpose Temperature Sensor
3. Outside Air Temperature Sensor
Water Heater Application
Water heater units are shipped with two sensors; the inlet water
temperature sensor and the multi-purpose temperature sensor
to be used as a tank sensor.
Placement of Sensors
Inlet Water Temperature Sensor
This sensor measures the inlet water temperature coming into
the unit.
Inlet Temperature Sensor
The inlet water temperature sensor is placed into the inlet
bulbwell on the boiler. This sensor is installed by the factory in
new units. Make sure to insert the sensor all the way into the
bulbwell, leaving no air pocket between the front surface of the
sensor and the back of the bulbwell. Air pockets are thermally
non-conductive and will cause sensors to not read accurately.
Multi-Purpose Temperature Sensor
Depending upon how your unit is set up, this sensor can be
used as a system sensor or a tank sensor.
Outdoor Air Temperature Sensor
This sensor is only available on boiler units with an outdoor air
reset option. This allows you to tie boiler operation to the
outdoor air temperature. As outside temperatures drop, the
control will increase the temperature setting of the boiler. As
outdoor temperatures rise, the control will decrease the
temperature to the selected set point of the boiler. You can set
the control to shut the boiler off when a desired outdoor air
temperature level is reached.
System Sensor
This is used for boiler applications. This sensor will control the
boiler operation based upon the water temperature within the
building loop.
Tank Sensor
This is used in water heating applications. Place the sensor in
the water storage tank to measure water temperature. For more
information on mounting the sensor, see Remote Mounting of
Sensors, page 33.
Outside Air Temperature Sensor
The outside air temperature sensor will only be used for boiler
systems. The outside air sensor is optional. You must purchase
the sensor from the appliance manufacturer. The sensor comes
with a housing that helps protect the sensor from the elements.
Mount the air sensor housing under the eve of the roof. Make
sure the housing is out of direct sunlight. This will ensure that
the sensor will accurately read the true outdoor temperature.
For more information on mounting the sensor, see Remote
Mounting of Sensors, page 33.
Figure 37 - Outdoor Air Reset Chart Example
32
Installation and
Service Manual
Remote Mounting of Sensor
HOT SURFACE IGNITION SYSTEM
You must mount the outside air temperature sensor outside the
building. To mount remote sensors, follow the guidelines
below. Take care to correctly wire sensors to the unit. Erratic
temperature readings can be caused by poor wiring practices.
Twist the wires between the unit and the remote sensor. Turn
wires at least three or four turns per linear foot of wiring. This
provides common mode rejection of some types of electrical
interferences.
Hot Surface Igniter and Ignition
Control Module
This unit has one ignition module and one hot surface igniter.
1. Do not route temperature sensor wiring with building
power wiring.
2. Do not locate temperature sensor wiring next to control
contactors.
Figure 38 - Hot Surface Igniter
3. Do not locate temperature sensor wiring near electric
motors.
 Caution: The igniter is extremely fragile, be very
careful when removing. A faulty or damaged hot surface
igniter MUST BE replaced with a Lochinvar PLT3400
igniter. Do not use general purpose field replacement
igniters.
4. Do not locate temperature sensor wiring near welding
equipment.
5. Make sure good mechanical connections are made to the
sensor, any interconnecting wiring and the controller.
6. Do not mount sensor with leadwire end pointing up in an
area where condensation can occur.
7. Use shielded wiring to connect the sensor to the control
when the possibility of an electrically noisy environment
exists. Shielded cable is recommended on all cable runs of
more than 25 feet in length.
F2
FC-
FC+
F1
P3
+
DS2
Note: Ground the cable shield at the connection to the boiler
temperature control only. Do not ground the shielded cable at
the sensor end.
To maintain temperature accuracy, sensor wires should be at
least 18 AWG, see Table N below.
TABLE - N
Remote Wire Connection
Figure 39 - Hot Surface Ignition Control Module
Wire
Maximum
Gauge
Allowable Length
12 GA
100 ft
14 GA
75 ft
16 GA
50 ft
18 GA
30 ft
33
Hydronic Heating Boilers and
Domestic Water Heaters
Ignition and Control Timings
OPERATION
Proven Pilot Hot Surface Ignition System F9 is standard on
models 495,000 through 2,065,000 Btu/hr and M9 is optional
on models 495,000 through 2,065,000 Btu/hr with One Hot
Surface Ignition Module.
Continued
Hot Surface Ignition Control Module
Ignition Module Lockout Functions
The ignition module may lockout in either a hard-lockout
condition, requiring pushing of the reset button to recycle the
control, or a soft-lockout condition which may recycle after an
approximate five-minute waiting period. This soft-lockout
condition is intended to allow self-correcting faults to correct
themselves and permit normal operation. A typical hardlockout fault is a flame failure condition. An ignition module
that is in a hard-lockout condition may only be reset by
pushing the reset button next to the ignition control or the
"RESET" button on the diagnostic panel on the left end of the
unit. Upon a flame failure, the reset button is only active after
the control module has completed its post-purge cycle. Turning
main power "OFF" and then "ON" or cycling the thermostat
will not reset a hard-lockout condition. Wait five seconds after
turning on main power before pushing the reset button when
the ignition module is in a hard lockout. The ignition module
will go into a soft lockout if conditions of low air, low voltage
or low hot surface igniter current are present. A soft-lockout
condition will operate the combustion air fans for the post
purge cycle and then the ignition module will pause for
approximately five minutes. At the end of this timed pause, the
ignition module will attempt a new trial for ignition sequence.
If the soft-lockout fault condition has subsided or has been
corrected at the end of the timed pause, main burner ignition
should be achieved with the resumption of the normal trial for
ignition sequence. If the control sensed fault is not corrected,
the ignition module will continue in the soft-lockout condition.
If the electronic thermostat opens during the soft-lockout
period, the ignition module will exit soft lockout and wait for
a new call for heat from the thermostat. A soft-lockout
condition may also be reset by manually cycling the thermostat
or turning the main power switch "OFF" and then "ON" after
the control sensed fault has been corrected.
Hot Surface Ignition Module Timings (Nominal)
Prepurge:
15 Seconds
Hot Surface Igniter Heat-up Time:
25- 35 seconds
Main Burner Flame Establishing Period:
4 Seconds
Failure Response Time:
0.8 Seconds at less than 0.5 µA flame current
Flame Current:
5 - 15 µA
Time Delay Between Stages 1&2:
10 Seconds
Post-purge:
30 Seconds
Pump Delay Timing:
30 Seconds after burner shutdown.
Diagnostic Status Indication
The ignition module has an LED which indicates the status of
the safety circuits. A remote Ignition Module Status indicating
light is wired from the ignition module Status LED and
mounted on the side diagnostic panel. The flashing operation
of this light indicates the diagnostic status of the ignition
control module. The status LED, mounted on the ignition
module flashes a code sequence from the Ignition Module to
indicate the status of the ignition process. See TABLE-N for
the flashing diagnostic status codes as signaled by the ignition
module.
34
Installation and
Service Manual
OPERATION AND DIAGNOSTIC
LIGHTS
TABLE - P
Status LED Diagnostic Codes
The diagnostic control panel has up to 6 indicating and
diagnostic lights to show all major steps of operation and
control sensed malfunctions. This panel is located on the left
end of the unit.
Code
Sequence
Prepurge
TABLE - O
Status LED Diagnostic Codes
Code Sequence
Constant ON
Constant OFF
System OK, no faults present.
Possible control fault, check power;
LED may be effective, do not replace
control if all operational sequences
function properly, see Trouble Shooting
Guide.
Low Air, check air pressure switch and
hoses to pressure sensing points, fan,
venting and sealing of pressurized
chamber. Note:Brief flashing normal on
fan start-up/proving.
Two Flashes
Flame without call for heat, check for a
gas valve stuck in the open position, air,
venting, burners and the combustion
process. Fan will remain on.
Three Flashes
Lockout due to flame failure, push reset
button on inner control panel after
correcting ignition problem. Initial heater
start up without properly bleeding air
from the gas line may require multiple
reset functions to achieve proper ignition.
Four Flashes
Igniter failure, igniter will not maintain
minimum 2.75 amp current draw, caused
by, low voltage, bad wiring/continuity,
high resistance or igniter failure.
Five Flashes
Power supply problem, check for low
supply voltage or transformer output less
than 18VAC.
Six Flashes
Operation of combustion
air fan before ignition on
Condition
One Flash
Condition Lights
Trial for Ignition
stages 1 and 2.
Hot surface igniter
preparing to light burners.
Stage 1 On
Burners for stage 1 operating.
Stage 2 On
Burners for stage 2 operating.
(985,000 - 2,065,000 Btu/hr)
Status
Remote status light for
ignition module.
Alarm
Indicates flame failure on
the ignition module and
will indicate additional
alarms if the alarm of any
failure option is purchased.
Models 495,000 - 745,000 Btu/hr
Models 985,000 - 2,065,000 Btu/hr
Replace ignition module, internal
fault.TA
Figure 40 - Operation/Diagnostic Lights
35
Hydronic Heating Boilers and
Domestic Water Heaters
3. Check the pump to be sure it is running properly and that
the pump motor is running in the proper direction (see
arrow on volute housing).
DOMESTIC WATER
HEATERS
4. Be sure the installed circulation pipes between the water
heater and storage tank are not less than 2 1/2" in diameter
on models 985,000 - 2,065,000 Btu/hr.
This section applies only to those units used to supply potable
hot water for domestic use. The hot water supply boiler must
be installed with a storage tank.
5. Common manifold piping for multiple unit installations
will require larger minimum pipe sizes and tank circulating
tappings to ensure proper flow. See TABLE-R.
This section contains specific instructions for those units used
to supply domestic hot water. All warnings, cautions, notes and
instructions in the general installation and service sections
apply to these instructions. Hot water supply heaters are
designed for installation with a properly sized storage tank.
The use of a properly sized pump and the control of water
velocity, as explained below, are important for correct
operation of your water heater.
If the temperature rise is too low, the water velocity
is too high. Adjust as follows:
1. Slowly throttle the valve on the outlet side of the water
heater until the temperature rise is steady at the required
temperature rise as noted in TABLE-Q.
2. Sustained high water velocity and low temperature rise
may result in pitting or erosion of the copper tubes in the
heat exchanger. This is a non-warrantable failure.
Temperature rise must be properly adjusted to achieve the
specified flow rate.
Water Velocity Control
IMPORTANT: To ensure proper velocity through
the heat exchanger, you must regulate the
temperature rise across the heat exchanger from
inlet to outlet. Do this upon initial installation and
periodically recheck. The correct temperature
rise across the heat exchanger ensures proper
velocity in the tubes. This will yield long life and
economical operation from your hot water
heater. Excessive lime build up in the tube is
caused by too low of velocity through the tubes.
Excessive pitting or erosion in the tube is caused
by too high of velocity through the tubes. Take
care to measure temperature rise and maintain a
velocity as follows:
Required Temperature Rise
Based on heating potable water with a hardness of 5 to 25
grains per gallon and/or total dissolved solids not exceeding
350 ppm, see Water Chemistry, page 37.
TABLE - Q
Temperature Rise Chart
Btu/hr
Temperature
1. With the pump running and the water heater off, the inlet
and outlet thermometers should read the same
temperatures. If they do not, an adjustment must be made
to your final calculation.
Input
Rise °F
2. Turn the water heater “On” and allow time for the
temperature to stabilize. Record the difference between the
inlet and outlet temperatures. This difference will be the
“temperature rise”.
3. Compare the temperature rise on the heater with the
required temperature rise in TABLE-Q. Should adjustment
be needed, proceed as follows:
If the temperature rise is too high, the water velocity
is too low. Check the following:
1. Check for restrictions in the outlet of the water heater.
2. Be sure all valves are open between the water heater and
the tank.
36
495,000
15
645,000
19
745,000
22
985,000
18
1,255,000
23
1,435,000
26
1,795,000
32
2,065,000
37
Installation and
Service Manual
Water Chemistry
TABLE - R
Pipe Sizing Chart
The required temperature rise and the standard pump sizing are
based on the heating of potable water with a hardness of 5 to
25 grains per gallon and a total dissolved solids not exceeding
350 ppm. Consult the appliance manufacturer when heating
potable water exceeding these specifications. Heating of high
hardness and/or high total dissolved solids water will require a
larger circulating pump, an optional cupro-nickel heat
exchanger and a revised temperature rise specification based
on the water chemistry of the water to be heated. Water with a
hardness of less than 5 grains per gallon will usually have a
low pH which can be aggressive and corrosive causing nonwarrantable damage to the heater, pump and associated piping.
Corrosion due to water chemistry generally shows up first in
the hot water system because heated water increases the rate of
corrosive chemical reactions.
495,000 - 745,000
985,000 - 2,065,000
Number
Common
Number
Common
of
Pipe
of
Units
Size (Min)
Units
Size (Min)
1
2"
1
2 1/2"
2
3"
2
4"
3
3"
3
4"
4
4"
4
5"
5
5"
5
6"
6
5"
6
6"
Pipe
COLD WATER
SUPPLY
Circulating Pump
EXPANSION TANK
(IF REQUIRED)
MIXING VALVE
1. The water heater must be connected to a properly sized
pump that circulates water between the heater and storage
tank.
HOT WATER
SUPPLY
CIRCULATING
PUMP
RELIEF
VALVE
LOCK-TEMP
STORAGE
TANK
RELIEF
VALVE
2. The pump is sized to heater input and water hardness. Care
should be taken to size the pump correctly. See Water
Chemistry on this page.
3. The water heater is equipped with a factory-supplied pump
delay system in accordance with the requirements of the
latest edition of ASHRAE 90.1.
DRAIN
4. Lubricate
the
pump
to
the
manufacturer’s
recommendations. Pump damage due to inadequate
lubrication is non-warrantable.
BUILDING
RETURN
5. Standard water heaters are furnished with the following
circulating pump. Mount the pump on the unit's inlet water
connection.
Figure 41 - Typical Water Heater Piping with Storage Tank
Pipe Size Requirements
Table-R, pipe sizing chart provides the minimum pipe size for
common manifold piping to ensure adequate flow.
495,000 -745,000 Btu/hr Models
1/4 HP, 120 VAC, 5.8 Amps
985,000 -2,065,000 Btu/hr Models
1/2 HP, 120 VAC, 7.4 Amps
This pump is sized based on installation of a single storage
tank and heater in close proximity. If the number of fittings
and straight pipe exceeds the quantities shown in this section,
a larger pump will be required.
ABLE-P
The standard pump selection is based on the following pipe
and fittings from the unit to the storage tank:
Pipe Sizing Chart
37
Hydronic Heating Boilers and
Domestic Water Heaters
Potable Hot Water Temperature
Control Settings
DOMESTIC WATER
HEATERS Continued
Domestic Water Temperatures
6 90° elbows
2 ball valves
2 unions
1 cold water tee

WARNING: You must take adequate care
to prevent scald injury when storing water at
elevated temperatures for domestic use.
Not more than 45 feet of straight pipe.
This unit has an adjustable temperature control to maintain the
desired water temperature set point. See Setting Temperature
Control, page 29, for instructions to program the temperature
control. The temperature control is factory preset at
approximately 125°F (52°C) or less. Households with small
children or invalids may require 120°F (49°C) or lower
temperature hot water to reduce risk of scald injury.
IMPORTANT: For every elbow and tee in excess
of those shown above, deduct 5 feet from
maximum allowable straight pipe in heater to
tank circulating loop.
Minimum Pump Performance
Operate this high efficiency hot water heater at a temperature
setting high enough to prevent condensing of the products of
combustion on the unit's heat exchanger or in the attached
venting system. A water temperature setting that is above the
dew point of the gas combustion products should prevent
condensate formation.
This is based on heating potable water with a hardness of 5 to
25 grains per gallon and/or total dissolved solids not exceeding
350 ppm. See Water Chemistry, page 37.
TABLE - S
Minimum Pump Performance
LE-Q

BTU/hr Input
495,000 - 745,000
985,000 - 2,065,000
GPM
Ft.Hd.
60
90
10
15
WARNING: To guard against scald injury,
you must use a properly-sized thermostatic
mixing valve to supply domestic hot water at
temperatures less than 125°F (52°C).
Minimum Pump Performance
Storing the water at a higher temperature and thermostatically
mixing the water increases the available quantity of mixed hot
water, greatly reducing the possibility of condensate forming
on the heat exchanger or in the venting system and helps
prevent water born bacteria growth.
Heat Exchanger
This is a highly sophisticated heat exchanger, designed to carry
water in such a way that it generates a scouring action which
keeps all interior surfaces free from build up of impurities. The
straight line, two pass design of the tubes sends water into the
headers at a properly rated velocity. The configuration of the
headers, in turn, creates a high degree of turbulence which is
sufficient to keep all contaminants in suspension. This
“scouring action” provides greater cost savings for owners.
Tubes are always able to transfer heat at peak efficiency. Every
surface within this water containing section is of a non ferrous
material, providing clear, clean, rust free hot water. Straight
copper tubes finned on the outside for maximum heat transfer
and coated cast iron one piece cored headers make up an
entirely rust proof unit. On all models, header inspection plugs
can be removed for field inspection and cleaning of copper
tubes. The entire heat exchanger may be easily removed from
the unit.
Some states may require a lower water temperature setting for
specific applications. Check local codes or your gas supplier
for domestic hot water temperature requirements.
• Water temperature over 125°F (52°C)
can cause severe burns instantly or
death from scalds.
• Children, disabled and elderly are
at highest risk of being scalded.
• See instruction manual before
setting temperature at heating
appliance.
• Feel water before bathing or showering.
• If this appliance is used to produce
water that could scald if too hot,
such as domestic hot water use,
adjust the outlet control (limit) or use
temperature limiting valves to obtain
a maximum water temperature of
125°F (52°C).
38
Installation and
Service Manual

Remember, no water heating system provides exact
temperatures at all times. Let the system operate a few days at
your desired settings to determine correct settings for your
needs.
WARNING: Should overheating occur or
the gas supply fail to shut off, do not turn off or
disconnect the electrical supply to the pump.
Instead, shut off the gas supply at a location
external to the unit.
1. These units are equipped with an operating temperature
control.
2. The control set points are preset to a low test setting when
shipped from the factory.
High Water Temperature Limit Control
The unit is equipped with an adjustable setting, auto-reset high
water temperature limit control. The hot water heater
temperature limit control has a maximum limit setting of
200°F (93°C). If water temperature exceeds the set point, the
limit will break the control circuit and shut down the unit. The
limit control will only be reset after the water temperature has
cooled below the set point of the limit. The high water
temperature limit control is mounted in the outlet side of the
front header. A manual reset high water temperature limit
control is available as an optional control.
3. Reset the temperature set points to the lowest settings
which will satisfy hot water demands, eliminate a possible
condensate problem and prevent a risk of scald injury.

WARNING: Return water temperatures
must not be less than 140°F (60°C). If lower
return wate temperatures are required, folllow
the instructions for Low Temperature Return
Water Systems, page 25.
Optional Relief Valve
4. The High-Fire Offset should normally be adjusted to “0”
when supplying potable hot water for domestic use.
This water heater is normally supplied with a temperature and
pressure relief valve(s) sized in accordance with applicable
codes. Units may be supplied with an optional pressure only
relief valve(s). When a water heater equipped with this
optional relief valve is piped to a separate storage vessel, the
storage vessel MUST have a properly installed temperature
and pressure relief valve which complies with local codes.
5. Stage firing can be achieved by adjusting the High-Fire
Offset to any value other than zero. Typically, a setting of
3°F is 5°F is suitable for stage firing in a water heater
application. Stage firing of a potable water heater is
normally only used to replace system standby heat loss.
6. All stages of burner operation should fire when there is a
major draw from the potable hot water storage system.
This prevents possible condensate problems and ensures a
rapid recovery of the hot water used.
Thermal Expansion
A relief valve which discharges periodically may be due to
thermal expansion in a closed system. A hot water supply
boiler installed in a closed system, such as one with a backflow
preventer or check valve installed in the cold water supply,
shall be provided with means to control expansion. Contact the
water supplier or local plumbing inspector on how to correct
this situation. Do not plug or cap the relief valve discharge!
Note: The High-Fire stage will be delayed by approximately
10 seconds to allow a soft start of the water heater.
IMPORTANT: When water is stored at
temperatures above 125°F (52°C), a thermostatic
mixing valve must be installed on the hot water
outlet from the storage tank to supply lower
temperature water and prevent the risk of a scald
injury.
Cathodic Protection
Hydrogen gas, which is extremely flammable, can be produced
in a hot water system that has been unused for a long period of
time (generally two weeks or more). To prevent the possibility
of injury under these conditions, open the kitchen sink hot
water faucet for several minutes before using any electrical
appliance connected to the hot water system. If hydrogen is
present, there will be an unusual sound such as air escaping
through the pipe as the hot water begins to flow. Do not smoke
or have open flames near the faucet at this time.
Note: This water heater, when set at a lower temperature
setting, is not capable of producing hot water of sufficient
temperature for sanitizing purposes.
Location of Cold Water Supply Piping
Connections
Incorrect piping of the cold water supply to the system may
result in excessive low temperature operation causing
condensate formation on the heat exchanger and operational
problems. You must install the cold water supply piping in the
discharge piping from the heater to the storage tank. This
allows the cold water to be tempered in the storage tank before
entering the heater. See Figure 41 and typical installation
drawings provided with the unit for correct piping. Higher
water temperatures reduce condensate formation.
39
Hydronic Heating Boilers and
Domestic Water Heaters
Lifting Flames: The usual causes for lifting flames are over
firing the burner(s), excessive primary air, or high draft.
CLEANING AND
MAINTENANCE
If you observe improper flame patterns, examine the venting
system, ensure proper gas supply, and ensure adequate supply
of combustion and ventilation air.
Listed below are items that must be checked to ensure safe
reliable operations. Verify proper operation after servicing.

Flue Gas Passageways Cleaning
Procedures
CAUTION: Label all wires prior to
disconnection when servicing controls. Wiring
errors can cause improper and dangerous
operation.
Any sign of soot around the outer jacket, at the burners or in
the areas between the fins on the copper heat exchanger
indicates a need for cleaning. The following cleaning
procedures must only be performed by a qualified serviceman
or installer. Proper service is required to maintain safe
operation. Properly installed and adjusted units seldom need
flue cleaning.
Appliance Area
Keep appliance area clear and free from combustible materials,
gasoline and other flammable vapors and liquids.
Water Circulating Pump
IMPORTANT: All gaskets on disassembled
components must be replaced with new gaskets
on reassembly. Gasket kits are available from
your distributor.
Inspect pump every six months and oil as necessary. Use SAE
30 non-detergent oil or lubricant specified by pump
manufacturer.
Burner Flames
Visually check main burner flames at each start up after long
shutdown periods or at least every six months. Burner
viewports are located on the right and left sides of the unit.
Burner Removal and Cleaning
1. Turn off main power to unit.
2. Turn off main manual gas shutoff to unit.
3. Remove the front outer jacket panels.
4. Disconnect manifold from gas train using union(s) just
below each gas valve(s).
5. Remove mounting screws from manifold mounting
brackets. Pull the manifold/orifice assembly away from
burners. Repeat for each manifold assembly.
6. Remove two mounting screws from burner and slide
burner out toward front of unit. Use caution to prevent
damage to burners, refractory, hot surface igniter or wiring.
7. Remove soot from burners with a stiff bristle brush. Dirt
may be removed from burner ports by rinsing the burner
thoroughly with water. Drain and dry burners before reinstalling. Damaged burners must be replaced.
Figure 43 - Flame Pattern Illustration

WARNING: The areas around the burner
viewports are hot. Direct contact with unit could
result in burns.
When installed in a dusty and dirty location, the burners may
require cleaning on a 3 to 6 month schedule or as needed,
based on severity of contamination. Contaminants can be
drawn in with the combustion air. Non combustible particulate
matter such as dust, dirt, concrete dust or dry wall dust can
block burner ports and cause non-warrantable failure. The
standard inlet air filter will help eliminate dust and dirt from
entering the unit. Use extreme care when operating a unit for
temporary heat during new construction. The burners could
require a thorough cleaning before the unit is placed in service.
Normal Flame: A normal flame is blue with slight yellow tips,
has a well-defined inner cone, and displays no lifting flames.
Yellow Tips: The usual causes for yellow tips on the burner
flame are burner air flow blockage or partial obstruction.
Yellow Flames: The usual causes for yellow flames are
primary air flow blockage to the burner(s) or excessive gas
input. Correct this condition immediately.
40
Installation and
Service Manual
Heat Exchanger Cleaning
Combustion and Ventilation Air
1. While burners are removed, check the heat exchanger
surface for sooting. If present, heat exchanger must be
cleaned and problem corrected. Proceed as follows.
Combustion Air Filter (Models 985,000 2,065,000 Btu/hr Only)
This unit has a standard air filter(s) located behind the
combustion air inlet panel(s). This filter helps ensure clean air
is used for the combustion process. Check this filter every
month and replace when it becomes dirty. The filter size is
12" x 16" x 1" (30.5cm x 40.6cm x 2.5cm). You can find this
commercially available filter at any home center or HVAC
supply store.
2. Remove gas manifold(s)/orifice assemblies as described in
steps 1 through 5 in Burner Removal and Cleaning, page
40.
3. Disconnect wiring from the hot surface igniter and hose
from the burner pressure tap.
4. Remove inner jacket panel mounting screws and slide door
assembly out toward front of the unit. Use caution to
prevent damage to the refractory and hot surface igniter.
To install filter, see Combustion Air Filter, page 8.
5. Check "V" baffles and frame runners along front and back
edges of heat exchanger. Remove and clean if necessary.
Air Flow
Check frequently to be sure the flow of combustion and
ventilation air to the unit is not obstructed.
6. Remove soot from heat exchanger with a stiff bristle brush.
Use a vacuum to remove loose soot from surfaces and
inner chamber.
Combustion Air Fan
7. The heat exchanger can be removed by sliding towards the
front of the unit. Once the heat exchanger is removed from
the unit, a garden hose can be used to wash the tubes to
ensure that all soot is removed from the heat exchanger
surfaces. Note: Do not wet the unit's refractory.
These units use a fan-assisted combustion process. These units
have one fan to supply combustion air to the burners.
Fan Cleaning
Check each combustion air fan every six months. Clean fan as
required when installed in a dusty or dirty location. Oiling is
not required.
8. Ensure that all burner ports are cleaned to remove any soot.
See Burner Removal and Cleaning, page 40.
9. Carefully reinstall the heat exchanger, "V" baffles, and
frame runners if removed from the unit. Note: Make sure
frame runners seal securely where they contact the front
and rear compartment refractory.
Combustion Air Fan Adjustment
The combustion air fan is factory preset and should not need
adjustment in most cases. Follow the steps below to adjust the
fan if a continuous Low Air Status Code occurs.
10. Carefully reinstall inner jacket panels, burners, manifolds,
wires and hoses. Use new gasket material to ensure a
proper air seal.
Check for proper installation and draft in the venting system.
Correct as required.
11. Reassemble all gas and water piping. Test for gas leaks.
12. Reassemble outer jacket panels.
Adjusting Differential Air Pressure
13. Cycle unit and check for proper operation.
The following is a recommended method for setting the
differential air pressure (P) for the fan.
Electrical
This unit uses a transformer to supply a low voltage control
circuit. The voltage on the secondary side should be 24 to
28VAC when measured with a volt meter. Larger models have
a 7AMP circuit breaker provided on the secondary side of the
transformer. A tripped circuit breaker indicates a short in the
24VAC controls that must be corrected.
41
Hydronic Heating Boilers and
Domestic Water Heaters
The " (+)" connection on the manometer connects to the tee in
the tubing from the units front chamber and the " (-) "
connection on the manometer connects to the tee in the small
tubing from the burner.
CLEANING AND
MAINTENANCE CONTINUED
Upon a call for heat, the fan will run for about 90 seconds
before going into soft lockout. If necessary, turn the power to
the unit OFF and then back ON again to recycle the fan.
Note: If the unit has been firing recently, allow the unit to cool
for five minutes with the fan running before beginning the
adjustment procedure.
Note: Retain the plastic caps removed from the tees for
reinstallation when complete.
4
3
Figure 43 - Air Pressure Switch
2
1
0
1
2
3
4
Figure 45 - Combustion Air Adjustment with a Manometer
to set Differential Pressures
Adjustment Procedure: 495,000 - 1,255,000 Btu/hr
Models
1. Remove the upper front jacket panels from the unit to
access the upper chamber.
2. Locate the air shutter on the side of the fan housing (see
Figure 44). Turn the adjustment screw on the air shutter to
open or close the shutter. Increase air shutter opening to
increase air pressure. Decrease air shutter opening to
decrease air pressure.
3. Adjust the air shutter until the differential pressure is
nominally 1.2 - 1.35 inches water column for models
495,000 - 745,000 Btu/hr and 1.1 - 1.3 inches water
column for models 985,000 - 1,255,000 Btu/hr. Note: The
air chamber pressure is 1.2 inches water column for
liquefied petroleum (L.P.) and 1.4 inches water column
for natural. See Figure 45 on installations up to 2000 feet
altitude. Contact the factory for high altitude pressure
settings.
Turn the adjustment screw on
the air shutter to open or close
shutter.
Figure 44 - Adjusting Air Shutter
Set Up Procedure
To the left of the fan is an air pressure switch with a large and
a small tube delivering pressure from points inside the unit (see
Figure 43). The pressure in the large tube is the chamber
pressure. The pressure in the small tube is the burner pressure.
They act together to make the pressure switch. By
disconnecting the caps from the tees in the pressure switch
hoses and connecting them to either side of a manometer, you
can read the differential pressure to the switch.
4. Once the adjustment procedure is complete, reconnect the
caps to the tees in the hoses to the pressure switches and
check all tubing and wire connections for a snug fit. Test
fire the unit. Reinstall upper panels.
42
Installation and
Service Manual
Adjustment Procedure: 1,435,000, 1,795,000 and
2,065,000 Btu/hr Models
1. Remove the upper front jacket panels from the unit to
access the upper chamber.
2. Slightly loosen the screws that attach the fan transition box
to the metal base (see Figure 46).
3. Locate the air shutter at the rear of the fan duct (see
Figure 47). Move the air shutter towards the rear of the unit
to increase air pressure. Move the air shutter towards the
front of the unit to decrease air pressure.
4. Adjust the air shutter until the differential pressure is
nominally 1.1 - 1.3 inches water column. Note: The air
chamber pressure is 1.2 inches water column for
liquefied petroleum (L.P.) and 1.4 inches water column
for natural. See Figure 45 for installations up to 2000 feet
altitude. Contact the factory for high altitude settings.
Figure 47 - Adjusting Air Shutter
5. Once the adjustment procedure is complete, reattach the
caps to the tees in the hoses to the pressure switch and
check all tubing and wire connections for a snug fit. Test
fire the unit. Reinstall upper panels.
Servicing Hot Surface Igniter and
Ignition Module
This unit uses a proven hot surface ignition module and a hot
surface igniter. The hot surface ignition module is not
repairable. Any modification or repairs will invalidate the
warranty.

WARNING: Do not attempt to repair a faulty
hot surface igniter or ignition module. Any
modification or repairs may create hazardous
conditions that result in property damage,
personal injury, fire, explosion and/or toxic gases.
Figure 46 - Loosening the Transition Box Screws,
1,435,000, 1,795,000 and 2,065,000 Btu/hr Models Only
43
Hydronic Heating Boilers and
Domestic Water Heaters
CLEANING AND
MAINTENANCE CONTINUED
7.
8.
9.
A faulty hot surface igniter or ignition module must be
replaced with an identical part. A specification igniter and
ignition module for this specific unit is available from your
local distributor. Do not use general purpose field
replacement ignition modules or igniters.
10.
11.
12.
Ignition System Checkout
1. Turn off gas supply to unit.
2. Turn electric power on.
13.
3. Adjust the set point on the temperature control to a setting
above water temperature or to the highest safe setting.
14.
4. The igniter will cycle on trial for ignition.
5. The ignition module will lock out and turn the alarm light on.
6. Adjust the Set Point Differential and High-Fire Offset to the
desired settings.
15.
16.
7. Turn on gas supply.
17.
8. Press the module reset button to reset the ignition module.
This is a red button beside the ignition module or on the
diagnostic panel on the header-end of the unit.
18.
9. If ignition system fails to operate properly, repair work must
be performed by a qualified service person or installer.
SEQUENCE OF OPERATION
OVERVIEW
This sequence of operation can be considered the order of
events in sequential order that occur after the appliance has
received a call for heat. The process begins with 120VAC
power entering the appliance and ends with the appliance
going into an idle state after completion of a successful call for
heat.
Note: The following descriptions do not include remotely
connected devices that may be connected to the appliance.
Refer to the wiring diagram for actual point to point wiring
connections that show power delivery.
1. The POWER switch is placed in the “ON” position.
2. 120VAC power is supplied to the control transformer
along with L1 and F1 on the ignition module.
3. 24VAC is supplied to the electronic temperature control,
the ignition module and the adjustable high limit control.
4. 24VAC is then supplied to the auxiliary limit control (if
equipped).
5. If equipped, 24VAC is supplied to a low water cut-off and
then to the high and low gas pressure switches.
6. 24VAC is supplied to the continuous alarm terminals A1
and A2 and then to the remote stage one terminal strip, 1C
and 1NO.
44
24VAC is supplied to the electronic temperature control.
The electronic temperature control then calls for heat.
24VAC is supplied to the intermittent alarm field safety
contacts, B1 and B2.
24VAC is supplied to the water flow switch (if equipped).
24VAC is supplied to the TH terminals on the ignition
module.
As power is applied to the TH terminals on the ignition
module, 120VAC is switched from the F2 terminal to start
the combustion air fan at full speed on the 495,000 745,000 Btu/hr models and at low speed on the 985,000 2,065,000 Btu/hr models.
24VAC is supplied to the C terminal of the air pressure
switch. As the low air switch makes, power is supplied to
the ignition module.
24VAC is then supplied to the PS terminals on the ignition
module as the air pressure switch makes to prove fan
operation..
The combustion air fan operates for the pre-purge period.
At the end of the pre-purge, 120VAC is applied to the hot
surface igniter and the trial for ignition light.
The hot surface igniter proves 1800 F (982 C) ignition
temperature by current draw through the ignition module.
The ignition module supplies voltage to the MV terminals
on to the gas valve(s).
F9 SINGLE STAGE FIRING
19. All gas valves on the 495,000 - 745,000 Btu/hr models and
approximately half of the valves on the 985,000 2,065,000 Btu/hr models open, supplying gas to the orifice
and burner inlet to pre-mix.
20. The gas/air mixture is forced into the burner and out of the
burner ports under pressure.
21. The hot surface igniter lights the gas/air mixture and then
serves as a flame sensor to prove main burner flame by
rectification.
22. After a time delay of 10 seconds, the remaining gas valves
on the 985,000 - 2,065,000 Btu/hr models open, supplying
gas to the remaining burners.
23. The gas/air mixture is forced out of the burners and out of
the burner ports under pressure.
24. The burners light by carryover from the burners currently
firing.
25. The heater is now firing at full rated input.
M9 MODULE FIRING
26. The first stage gas valve(s) opens and supplies gas to the
orifice and burner inlet to pre-mix.
27. The gas/air mixture is forced into the burner and out of the
burner ports under pressure.
28. The hot surface igniter lights the gas/air mixture and then
serves as a flame sensor to prove main burner flame by
rectification.
Installation and
Service Manual
venters, etc.,). As such, it may be necessary to locate and turn
off power to these items before attempting to service the unit.
29. Burners are now firing for approximately 50% of the
heater’s input.
30. 24VAC is supplied from the second stage of the electronic
temperature control across the 2C and 2NO terminals on
the terminal strip on to a control to a relay.
31. The control relay switches the fan on the 985,000 2,065,000 Btu/hr models to high speed and energizes the
gas valves for the remaining 50% of burner input.
32. The remaining gas valves open and supply gas to the
orifice inlet to pre-mix.
33. The gas/air mixture is forced out of the burner ports and
light by carryover from the burners currently firing.
34. The heater is now firing at full rated input.
Low Voltage Supply Transformer
A 120VAC to 24VAC transformer located within the control
panel provides 24VAC/60Hz to many of the components
located on the unit. One of its 24VAC outputs (blue) is
connected to a circuit breaker and the other (yellow) is
connected to chassis ground.
24VAC Circuit Breaker
A circuit breaker is provided on the 985,000 - 2,065,000 Btu/hr
models for protection of the low voltage supply transformer
from overloads and short circuits. The breaker is located inside
the unit on the lower right corner of the control panel. Power
from this breaker goes to the electronic temperature controller,
ignition module and various other components and/or options
on the unit. When tripped, all factory-installed 24VAC
components will lose their 24VAC power.
HEAT TRANSFER PROCESS
35. Heated products of combustion pass over the heat
exchanger transferring heat to the water.
36. The rate of flue product movement is controlled by “V”
baffles on the heat exchanger to maximize heat transfer.
37. Flue products pass into the flue collector and are
exhausted from the unit.
Manual Reset High-Limit Thermostat
A manual reset high limit thermostat is provided as backup for
the temperature controller. This will either be an adjustable dial
or fixed temperature bulb-capillary style thermostat that will
trip and require resetting should water temperature exceed its
settings. When tripped, all controls remain powered, but
24VAC is prevented from being delivered to the ignition
module's thermostat input.
END OF SEQUENCE
38. Set point for the high fire on the electronic temperature
control is satisfied.
39. Power to all valves is turned OFF on F9 systems and
power to the high fire gas valves is turned OFF on M9
systems.
40. The water temperature continues to rise and the set point
for low fire is satisfied (M9).
41. Power to the low fire gas valves is turned OFF (M9).
42. The combustion air fan runs for a 30 second post purge
timing and turns OFF.
43. The appliance is now in a Standby Mode waiting for the
next “call for heat”.
EMS/Sequencer/Remote Aquastat
Terminals
The EMS/sequencer/remote aquastat terminals are provided
for connection of the unit to an external energy management
system or sequencer and are located along the top edge of the
terminal strip located within the electrical wiring box. In
addition to providing a means to externally stage fire the unit,
these terminals also provide for remote shutdown and override
by routing through dry contacts from external devices.
Connection of the external dry contacts to these terminals
requires the removal of one or more factory installed jumpers
located on the terminal strip.
GLOSSARY
Power Supply
(AC120VAC/60Hz)
120VAC/60Hz/1PH power connects to black (line) and white
(neutral) wires located within an electrical wiring box located
on the left side of the unit. A green chassis grounding wire is
also provided for connection to earth ground.
Safety Device Terminals
The safety device terminals ensure that no power can be
delivered to the ignition module unless factory/field-installed
safety devices such as flow switches and gas pressure switches
are closed. These safety device terminals are located below the
EMS/Sequencer/Remote Aquastat terminals located within the
electrical wiring box. Two types of connections are offered:
Continuous terminals provide for connection of safety devices
that are desired to be constantly monitored. Intermittent
terminals are provided for devices that are only monitored
during a "call for heat" cycle. Connection to either of these
terminals requires the removal of a factory-installed jumper
located on the terminal strip.
ON/OFF Rocker Switch
The black line voltage wire runs directly to a single pole, single
throw On/Off rocker switch located behind the front cover
accessible by a thumb screw. Turning ON the rocker switch
delivers line voltage to the low voltage transformer and
ignition module.
Note: The On/Off switch does not provide for disconnection of
power being supplied to any remotely connected devices that
may be connected to the unit (i.e. pumps, louvers, power
45
Hydronic Heating Boilers and
Domestic Water Heaters
Electronic Temperature Controller
Relay Board (Controlled by Electronic
Temperature Controller and Ignition Module)
A small relay board is provided on the 985,000 - 2,065,000
Btu/hr models to switch the blower from low to high speed and
to deliver power from the low fire stage (Stage 1) to the high
fire stage (Stage 2) depending upon the electronic thermostat's
settings.
(Operator)
A 2-stage electronic temperature controller is provided on the
unit and it serves to maintain a user selectable temperature set
point. Ultimately, the temperature controller delivers 24VAC to
the ignition module and pressure switch when it senses heat
mode is desired. It also activates the pump relay. If more heat is
needed, it activates the high fire stage.
Ignition (Ignition Module Function)
Once the trial for ignition period has been completed, the
ignition module sends 24VAC to the gas valves on the low fire
stage (Stage 1). Gas valves should open and allow gas to flow
to the burners in Stage 1 being energized. The fuel/air mixture
should ignite from the hot surface igniter. Once this voltage has
been sent to the valves, the hot surface igniter is turned off. The
ignition module then monitors the status of the flame and will
either allow ignition to continue or shut down the gas valves
should flame not be proven and proceed to a Flame Failure
condition. If flame was proven briefly during the ignition
period, the module may not proceed to Flame Failure, but
rather post-purge and then go into another trial for ignition.
Ignition Module
(Controlled by Electronic Temperature Controller)
One ignition module is provided on the unit. Upon sensing the
24VAC delivered to it by the electronic temperature controller,
the ignition module checks for a shorted pressure switch and
then, provided the air switch isn't shorted, supplies 120VAC to
its blower output relay and waits for a pressure switch signal.
Two Speed Blower (Controlled by Ignition
Module and Relay Board)
A single 2-speed blower on the 985,000 - 2,065,000 Btu/hr
models (single 1-speed blower on the 495,000 - 745,000 Btu/hr
models) provide combustion air to the unit. The blower is
provided with a high and low speed tap. The blower operates
in tandem with the ignition module when a call for heat signal
is received. Depending upon the number of stages in operation,
the blower's speed may increase or decrease accordingly.
Heat Transfer Process (Gas Valves, Burner,
On)
One pressure switch is provided to monitor the blower On/Off
operation. Upon a call for heat, 24VAC is delivered to the
pressure switch. If the blower generates adequate air pressure,
the pressure switch closes to deliver 24VAC to the ignition
module pressure switch monitoring input terminal.
and Heat Exchanger)
Once flame has been proven, the ignition module will hold the
gas valves open as long as there is proof of flame and a call for
heat is present. If the low fire stage cannot provide enough heat
to raise the system temperature, the electronic temperature
controller turns on the high fire stage. The high fire stage will
operate until the system water temperature shows a gain that
can be handled by low fire operation. The high fire stage shuts
off at this point. When the low-fire stage alone produces more
heat than is required, the electronic temperature controller
turns off the call for heat.
Prepurge (Ignition Module Function)
Post-Purge (Ignition Module Function)
Once the ignition module sees a 24VAC input from the
pressure switch, it runs the blower for approximately 15
seconds in order to purge the combustion chamber of any
unburned fuel/air mixture.
When 24VAC is removed from the ignition module's
thermostat input, the module turns off the gas valves and
maintains the blower for approximately 25 seconds in order to
allow the combustion chamber to be purged of all combustion
by-products.
Pressure Switch (Activated by Blower Turning
Trial for Ignition (Ignition Module Function)
Once the ignition module has completed its prepurge period, it
turns on the hot surface igniter. Once the hot surface igniter's
current draw reaches a proper level, the ignition module begins
a trial for ignition period of approximately 25 seconds to allow
time for the igniter to reach the ignition temperature necessary
to ignite the fuel/air mixture.
Pump Delay (Electronic Thermostat Function)
When the electronic thermostat removes 24VAC from the
ignition module, it continues to hold the pump relay on for 30
seconds in order to get the remaining heat out of the
combustion chamber. The pump then turns off to prevent the
heat in the water from going back into the combustion chamber
and up the flue.
Igniter (Controlled by Ignition Module)
Idle (Electronic Thermostat Function)
After completion of the post-purge cycle, the unit will go into
an idle state whereby the electronic thermostat continuously
monitors the water temperature until the water temperature
drops to levels that require additional heat.
One igniter is provided in order to ignite the fuel/air mixture
and its on/off operation is controlled by the ignition module.
46
BK
47
1
120
VAC
DOTTED LINE
INDICATES OPTIONAL
EQUIPMENT
CLOSED END SPLICE
JUNCTION POINT
(ELECTRICALLY SAME)
INDICATES
"C"
NO
PR
PR
LWCO IND.
P
O
G
RESET
J4
3
2
1
RE S E T
4
1
BL
2
3
BR/W
5
4
6
1
C
CN1
2
3
R
NO
J3
J1
OFF
R
BR
24V COM
R
Y
BL
T
LWCO
ALARM
CONTACTS
24V COM
24V COM
TEST SWITCH PROBE
T
HIGH-FIRE
OFFSET
OPERATOR
DIFFERENTIAL
BR
Y
RATIO
DISABLE
SHUTDOWN
O.A.
ENABLE
NC
OPTIONAL I/O RESET
O.A. MAX.
SHUTDOWN
COM
1
2
CN2
R
NO
Y
CN3
O
O
CN9
CN6
O
R
C
PR
PR
BK
BK
Y
Y
24V COM
NC
R
B
C
C
INLET
SENSOR
R
Y
G
PU
Y
IGNITER
G
BL
FLAME FAILURE
R/O
C
C
BR
BR
TD O/W
NO
NO
BR
W
SILENCE
R2
W2
ALARM
CONTACTS
OPTIONAL
24VAC ALARM
BELL
OPTION BOX "C" ONLY
R
R
BR
GY
GY
PU/W
T
BL/W
R/O
FIELD PROVIDED
REMOTE OPERATOR
O
O
GY/W
TRIAL
GY
+
2
PS
FF
1
G
R
"B"
BK
C
BR
W
L
PV
Y
BLOWER
W
W
MV
HEATING
MV
PV
OPEN
BK
NO
W
R/O
R
BK
BK
W
120VAC
POWER
PV/MV
Y
Y
PV/MV
HIGH FIRE VALVE
R
R
G
LOW FIRE VALVE
R
Y
FLASH
CODE LED
BR
ACC.
PLUG
SCHEMATIC/LADDER DIAGRAM LBL20034 REV A
OPTION BOX "A", "B" OR "C"
C
"X"
CLOSED
"FIELD PROVIDED LOUVER PROVING SWITCH" TO LOUVER OR
DAMPER
IGNITION
MODULE
"F2"
120V NEUTRAL
HI-LOW FIRE
FULL-FIRE STANDARD
IGNITION
MODULE
24COM
RESET
24VAC
10
9
8
7
6
5
4
TH
1 S2/FS
NEU
NOT
USED
F2
W
BR
W
BR
NORMALLY OPEN BR
VENT VALVE
SHUTOFF/
SOLENOID
F1
MV
BK
5 S1
LINE
4
-
FLAME
CURRENT
TEST PINS
FLAME FAILURE RESET
Y
BL
LOW AIR
IND.
BURNER GROUND
OPTIONAL ALARM ON ANY FAILURE
T
LOW AIR
OPEN
LOUVER
SYSTEM/TANK
SENSOR
R/O
O
NC
O.A.
SENSOR
HiGas
O/W O/W
SYS/
TANK
CN5
CN4
NO
X
IGN MODULE PIN 5 (MV)
T
C
LoGas
INLET
PROBE
C
OPERATOR CN1 (4)
OPTIONAL
AUX. LIMIT
SENSOR
R
ON
CN1
COM NC
R/O
O
SETPOINT
W1
CN7
CN8
Y
BL
O
R1
HI-LIMIT
FIELD
OPTIONS
INTERMITTENT
FIELD PROVIDED
COM
REMOTE OPERATOR FLOW SWITCH
DISCONNECT POWER BEFORE SERVICING THE UNIT
O.C.
OPTION BOX "B" OR "C"
"R1"
M
PR
PR
GND
F
C
PU
O
O
PUMP RELAY
Y
BL
DC 24V COIL
BL
NO
BK
CONTINUOUS
FLOW
SWITCH
COM
W
W = WHITE T=TAN
BK = BLACK Y=YELLOW
PR=PURPLE BR=BROWN
BL=BLUE
G=GREEN
P=PINK
GY=GRAY
O=ORANGE R=RED
Y
BL
24VAC
W
P
BL
O
3
W
POWER SWITCH
2
BK/W
W
120VAC/60HZ Neutral
OPTIONAL
LWCO OR LWCO
WITH ALARM
ITEM
W
BK
PUMP
OPTIONAL
ON BOILER
CHASSIS
GROUND
BK
24VCOM
G
24 GND
OPTIONAL LOUVERVENTER CONTACTS
Ground Line
SCHEMATIC DIAGRAM
MODELS 495,000 - 745,000 BTU/HR
J2
WIRING DIAGRAMS - MAIN UNIT CONNECTIONS
MODELS 495,000 - 745,000 BTU/HR
TERMINAL STRIP - SENSOR
O
5
NO C NC
PINS 1 & 2
JUMPERED
PROVIDED
IF NO
OPTIONS
ARE
ORDERED
HI-LIMIT
R
2C 1
BK/W
AUX
HI-LIMIT
W
OPTIONAL
BK
W
BK/W
PR
R/O
JUMPERED IF
NOT PROVIDED
O
POWER
SWITCH
BK
13
15
12 11 10
8
7
6
5
4
H
PR/W
O PT. BOX.
O/W
Y
O/W
BR
W
O
STAGE 1
STAGE 2
120VAC
P
2
5
11
14
BL
1
4
10
13
R1 W1 R2 W2 A X B C
NORMALLY
OPEN VENT
VALVE
OPTIONAL
BL
24VAC COM
PR
LOW GAS
NC
5 S1
BK 4 LINE
W
GY/W
NC
2
NOT
USED
NEU
24V
A
PUMP DELAY RELAY
"24VDC"COIL
CONTROL PANE
1 S2/FS
W = WHITE T=TAN
BK = BLACK Y=YELLOW
PR=PURPLE BR=BROWN
BL=BLUE G=GREEN
GY=GRAY
P=PINK
O=ORANGE R=RED
P
BL/W
BL
T
R
PR/W
9
8
7
6
5
4
3
2
1
TH
PI
24COM
RESET
24VAC
MV
PS
M/S
FF
C
BR O
IGNITION
MODULE
3
4
7
2
5
8
1 6
9
O
T
J4
GND
P
O
G
R
PR
Y
Y
G
T BR/W
G
O
P
Y
Y
SPLICE
WHEN REPLACING DAMAGED WIRING, USE EQUIVALENT TYPE AND GAUGE.
NO C
NO C
OPTION BOX "C"
T
O/W
O BR
SPLICE SPLICE
DISCONNECT POWER BEFORE SERVICING THE UNIT
Y
NO
C
GND
P
PR
P
J2
1 2 3
BL
IGNITION MODULE
48
PR
RE SE T
NORMALLY
CLOS ED
BL
Y
Y
MATING
BLOCKS
J3
PR
BL/W
FLAME FAIL RESET
BL
x
T
T
O.C.
TIME
DELAY
DOTTED LINES INDICATE
OPTIONAL EQUIPMENT
UNLESS OTHERWISE
INDICATED
10
1
NO
F2
F1
BK/W
BK
4
COM
DC
2
LOUVER
B
5
CONNECT TO:
R1 - W1 =
CONTINUOUS PUMP
X&B =
INTERMITTENT PUMP
24COM
GND
3
OPTIONAL
12
6
T
11 14
6
W
O
NC
BL
NC
NO
5
HIGH GAS
COM NO
BL
COM
7 10 13
BR
3
G
OPT. REMOTE
THERMOSTATS
3
4
O
OPTIONAL HIGH-LOW GAS PRESSURE
COM NO
G
GY
SHUTOFF/ NORMALLY OPEN
VENT VALVE
(HIGH
ON/OFF
(LOW FIRE) FIRE)
7
O
GAS TRAIN
W
BR
LIMITS
7
4
8
SHUTOFF
VALVE
120VAC
FLOW
SWITCH
12
SPLICE
R/O
NOT USED
P
STANDARD
O PT. BOX.
1 W
2 BR
1
2
R/O
6
1
2
6
1
B
3
ACCS.
PLUG
3
BK
R
O
O
BL
PR
HI-LIMITS - PWR SW
Y
BL
O
Y
24VAC FLAME
FAILURE
1
3
GY
C
J1
OPTIONAL
SYSTEM/
TANK
SENSOR
9
GY
120 VAC
TRIAL
24 VAC
HEATING
BK
PR PR
OPTION BOX CONNECTOR
SPLICE
NO C NC
GY
GY
9 12
INLET
SENSOR
2C 1
Y
3
8 11
3
SPL ICE 4
3
7 10
2
SPLICE 9
2
6
BK
2
6
1
SPLICE 2
5
15 12 9
5
3
F
1
SPL ICE 7
14 11 8
E
D
4
24 VAC
CONT ROL
G
H
9 12 15
6
3
R
5
8 11
1
SPLICE 10
1
7 10 13
SPLICE 1
1
6
4
13 10 7
4
SPLICE
3
D
4
BK
1
BR
BR
WIRING DIAGRAMS - MAIN UNIT CONNECTIONS
MODELS 495,000 - 745,000 BTU/HR (CONTINUED)
G
CHASSIS GROUND
1
4
11 14
2
12 15
3
10 13
7
10 13
5
8
11 14
6
9
12 15
BK
W
1
E
2
BK
SPLICE
W
Y
9
12 15
2
8
11 14
R/O
1
7
10 13
R
BLOWER
HI-LOW FIRE
FULL FIRE
SPLICE
F
Y
T
O
PR
GY
COM
G
BURNER
GROUND
SPLICE 5
PV
MV/PV
MV
LOW AIR
INDICATOR
PV
MV/PV
MV
GY
SPLICE 4
BK
Y
SPLICE
Y
3
120VA
C
PUMP
W
BK
G
VALVE #1 AIR PRESSURE
SWITCH
HOT SURFACE IGNITER
GR
BR
W
GROUND
VALVE #2
MAIN UNIT - GAS VALVES - BLOWER PRESSURE SWITCH
O
Y
BK
BL
SPLICE 6
SPLICE 8
O
SPLICE 9
120VAC
SUPPLY
W
24 VAC
OA SENSOR
3
Y
2
5
8
11
BL
R/O
O
1
4
7
10
BK
A
1
ENABLE
4
7
10
2
5
8
11
3
6
9
12
O.A. MAX.
PR
CN6
PR
W
CN9
SETPOINT
3
4
2
5
1
6
TO LOUVER OR
DAMPER
9
ALARM BELL
SILENCE
G
BL
OPERATOR
NEL
W
C
TO
CN9
HIGH-FIRE
OFFSET
DIFFERENTIAL
2
OPTION BOX "A"
SYS/
TANK
OFF
1
2
LOUVER/DAMPER
120 VAC RELAY
CN5
RATIO
1
BK
CN2
OPTIONAL I/O RESET
CN1
4
CN4
DISABLE
SHUTDOWN
O.A.
SHUTDOWN
BK
BK
2
INLET
PROBE
2
1
BK
CN3
SENSOR
1
120VAC
POWER
BK
2
ON
C
1
BR
6
4
3
4
2
O R
CN7 OPERATOR
CN8
CN1
LOW VOLTAGE
XFMR.
3
W
12
9
6
BR
BR
W
Y
NO
C
C
C
W
1
3
3
4 5
6
6
5
4
7
9
9
8
7
1
BR
O
PR
T
BR
NC
NO
G
PR
BR
O
Y
8
R
R
PR
PR
PR
P
T
O BL
"C"
LWCO INDICATOR
W
6
BK
BK
2
4
J4
GND
G
LWCO
ALARM
CONTACTS
24 VAC
RELAY
1
1
BK
2
2
BK
1
BR/W
G
P
BR
G
6
2
4
O
O
2
TO LOUVER OR
DAMPER
1
3
3
4
5
6
6 5
4
7
8
8
7
BK
BK
1
1
BK
2
2
BK
BR
WIRING CONNECTIONS DIAGRAM
49
O
P
OPTION BOX "B"
SPLICE
RR
1
120VAC
POWER
4
G
BR
BR
P
CONTACTS
FOR
LWCO ALARM
T
T
2
BR/W
LOUVER /DAMPER
120 VAC RELAY
BR/W
6
W
3
4
BR/W
BR
"R1"
120VAC
POWER
6
5
BR/W
Y
J3
O
J2
1 2 3
Y
LOUVER /DAMPER
120 VAC RELAY
T
O.C.
CONTACTS
FOR
ALARM
O
P
SPLICE
TEST
P
PR
`
~~~~
~~~~
BL
RESET
~~~~
~~~~
BR
BR/W
O/W
T
LWCO
PROBE
T
T
LWCO
PROBE
NORMALLY
CLOSED
ALARM BELL
24 VAC
CONTROL
SILENCE
J1
TEST
W
P
"R1"
O
TO LOUVER OR
DAMPER
BL
LBL20007 REV A
G
1
2
ON/OFF
POWER
SWITCH
BK
COM
FAIL
COM
OK
FAIL
HIGH/LOW GAS, AUX. HI-LIMIT
AUX. LIMITS, EXT. FLOW SWITCH
EXAMPLE DEVICES:
BARS REMOVED AND ATTACHED
DEVICES IN NON-ALARM STATE.
NOTE: SHOWN WITH SHORTING
Y
Y
Y
-Y
W
Y
TEST
NC
1
BR
PR
RESET
T
PR
T
PROBE SWITCH
C
P
1
J2
J4
O
BL/
BK
3
2
1
6
5
4
J3
T
O.A.
SENSOR
GND
RESET
2 3
O
NC
O.C.
24 VAC
LWCO
C
NO
BL/
BK
PR
AUX. HILIMIT
= R E LA Y S LO C A TED O N C O N TR O L
PA N EL
~~~~~~~
~~
~ ~~
= O PTI O N A L D I N R A I L C O N N EC TO R S
LO C A TED I N ELE C TR I C A L W I R I N G B O X .
= LE D S LO C A TE D O N D I S PLA Y B O A R D
R = R E LA Y S LO C A TED I N W I R I N G B O X
R
Y
BL
BL
BL
2
NO
HI-LIMIT
PR
PR
Y
BL
O PR
PR
C
HiGas
PR
O.A. MAX.
ENABLE
RATIO
W1
DISABLE
SHUTDOWN
O.A.
ON
CN7
SENSOR
PUMP
OPTIONAL ON
BOILER
PR/BK
PR/BK
O/
BK
W3
W2
TO
CN9
BR
O
4
3
OFF
CN1
CN7
CN8
LOW FIRE
1C 1NO
STAGE #1
C
BL
Y
PU
NC
NO
BK
W
BK
P
A3
PUMP RELAY
DC 24V COIL
BR
A2
PR
OPTIONAL
I/O RESET
BOARD
BOILER ONLY
A1
CONTINUOUS
ALARMS
TO POWER
SOURCE
BL & Y = 24VAC
SHUTDOWN
C
LoGas
PR
.
STRIP REQUIRE THE REMOVAL OF SOME OF THE SHORTING BARS FROM THE TERMINAL STRIP
SETPOINT
2
1
B1
B3
C
NO
O/BK
CONNECTS HERE
DIFFERENTIAL
BLANK COVER
PROVIDED IF
NO I/O RESET
OPTION IS
PROVIDED
CN3
CN9
CN6
SYS/
TANK
CN5
CN4
HIGH-FIRE
OFFSET
2
1
CN2
Y
R
BL
R
PR
PR
R
BR
BR
BL
Y
INLET
SENSOR
O/BK
OPTIONAL
TD
SYSTEM/TANK
SENSOR
R/BK
CONTACTS
ANY FAILURE
INLET
PROBE
OPTIONAL
ALARM BELL
SILENCE
ALARM
CONTACTS
O
~ ~~
NC
~ ~~
FACTORY FLOW SWITCH
B2
PR
OPERATOR
2-STAGE THERMOSTAT
BR
INTERMITTENT PR
ALARMS
FIELD SUPPLIED
SAFETY DEVICES
PR
O
PR
PR
BL
BL
C
C
NO
Y
Y
NO
Y
NC P
NO PR
+
3
NEU
9
8
7
6
5
4
3
2
1
10
11
+
-
Y
TH
PI
24COM Y
RESET
24VAC
MV
R
PS
IGNITION
M/S
MODULE
FF
1 S2/FS
2
F2
F1
W
BK
5 S1
LINE
4
-
Y
HIGH FIRE
2C 2NO
R/BK
STAGE #2
OPTIONAL
R/BK
CONTACTS
ANY FAILURE
AL
FFR
BL
T/
W
P
GY
GY
PR/BK
LOUVER
PROVING
BL/W
O
GY
PR/ PR/
BK BK
T
GY
TRIAL
RESETS
C
P
ALARM
PR/
BK
LOW AIR
BL
PURGE
IGNITER
G
BURNER
GROUND
BK
FLAME CURRENT TEST PINS
NO
R
C
W
NO
NC
W
R/BK
INDICATES
DOTTED LINE
INDICATES OPTIONAL
EQUIPMENT
CLOSED END SPLICE
JUNCTION POINT
(ELECTRICALLY SAME)
Y
Y
LBL20014 REV- A
W = WHITE
T=TAN
BK = BLACK
Y=YELLOW
PR=PURPLE
BR=BROWN
BL=BLUE
G=GREEN
P=PINK
GY=GRAY
R=RED
O=ORANGE
Y/G = YELLOW WITH GREEN STRIPE
ITEM
Y
Y
Y
HIGH FIRE VALVE(S)
STAGE #1 LED
LOW FIRE VALVE(S)
R/BK
R
R
Y
P
RUN-TIME
P
CONTACTS
OPTIONAL
Y
BLOWER
RUN-TIME RELAY
NO
HIGH
LOW
LOUVER/
POWER
VENTER
CONTACTS
OPTIONAL
R
BK
R RT
NO
NC
HL
C
STATUS
R/BK
R
GY
NC
HIGH/LOW FIRE & BLOWER
SPEED CONTROL RELAY STAGE #2 LED
R
LR
GY
BK/W
BK/
W C
C
(3) SCHEMATIC IS WIRING DIAGRAM, REFER TO ACTUAL COMPONENTS FOR EXACT TERMINAL LOCATIONS.
(1) WHERE POSSIBLE, ALL SWITCHES AND CIRCUITRY ARE SHOWN IN THEIR AT REST STATES
.
(2) ADDITION OF ENERGY MANAGEMENT SYSTEMS OR OPTIONAL LIMIT SWITCHES TO THE TERMINAL (4) WHEN REPLACING DAMAGED WIRING, USE EQUIVALENT TYPE AND GAUGE.
NOTES:
FIELD SUPPLIED
SAFETY DEVICES
WARNING: THIS HEATER MAY BE CONNECTED TO ONE OR
MORE BRANCH CIRCUITS. TO PREVENT ELECTRICAL SHOCK,
ENSURE ALL BRANCH CIRCUITS ARE DE-ENERGIZED BEFORE
ATTEMPTING TO SERVICE THIS EQUIPMENT.
BL
W
BK
BL
+
24
VAC BL
120
VAC
BK
60Hz
BK
CONTINUOUSLY INTERMITTENTLY
MONITORED
MONITORED
OK
A1 A2 A3 B1 B2 B3
CONTINUOUS INTERMITTENT
FIELD INSTALLED
SAFETY DEVICES
BK
CIRCUIT
BREAKER
CHASSIS
GROUND
W
Neutral
CHASSIS
GROUND
120 VAC
15AMPS
J1
Ground Line
SCHEMATIC AND WIRING DIAGRAM
MODELS 985,000 - 2,065,000 BTU/HR
50
BL
1
2
3
4
5
6
7
8
9
10
11
12
DISPLAY
BOARD
I/O RESET
O.A. MAX.
2
1
51
BL
R
T/W
O
P
Y
PR/BK
BL/W
W
TH
PI
24COM
RESET
24VAC
MV
PS
M/S
1 FF
9
8
7
6
5
4
10
1 S2/FS
+
-
24V
-24V COM
CN9
CN6
IGNITION
MODULE
BL/W
BL/W
BK
W
3
F2
F1
4 BK
+
5 S1
-
NEU 2
GY
W3
BK
BL
CIRCUIT
BREAKER
BL
FLAME
FAIL
RESET #2
BK/W
R/BK
PR
PR
R
BR
BR
BK/W
SYS/
TANK
CN5
R/BK
CN4
INLET
PROBE
CN3
BL
BK/W
R/BK
3
C
C
R
BK
9
8
7
6
R
1
2 3
6
3
9
8
7
MAIN UNIT
CONNECTOR
5
4
4
2
1
R
R/BK Y
O
5 4 8 12 10
SHRIN
K
TUBIN
G
9
15
14
11
12
13
10
PR
BR BR Y BL
O/B T/W
R/BK
STG #1
1
O
NO NC
NO
11
BR
FULL-FIRE/
BLOWER RELAY
SOCKET TOP VIEW
Y
2
R/ R/
BK BK
6
5
2
3
4
1
Y
PR
8
PR
F
D
6 7 8 9
BL
BL/
BK
2
G
15
T
1
GY
LINE
E
IGNITER
CONNECTOR
3
GY
TO
LWCO
7
4
5
6
BK
1
9
BL/
BK
14 13
O
3
W
T W R BK
7
T
T
BR
1
2
3
6
2
2
NOT
USED
P
P
3
W
3
R
R
Y
NOT USED
Y
4
BK/
W
4
5
4
3
2
1
4
3
2
1
P
A
5
OPTIONAL
P
P
OPTIONAL
RUNTIME
CONTACTS
NEUTRAL
1
BK G
1
C
Y
R
PR
Y
CHASSIS GROUND
J4
GND
J2
PR
PR RESET
PR
1
2
P
3
RESET
P
BL
24V
COMMON Y
Y
Y
W
24 VAC
LWCO
PR
BK
G
4
Y
2
5
T
3
6
BL/
O BK BL
1
Y
3
3
P
SHRINK
TUBING
PR/
BK
Y
BL PR/
BK
PR
P
1
1
2
2
CONNECTED UNLESS
ALARM ADDED
J3
6
Y
T
J1
9
5
O
5
7
4
1
BL
7
BL
BL/
BK
4
TO
LWCO
F
LBL20015 REV A
O.C.
3
6
9
CHASSIS
GROUND
ALARM
FLAME FAIL
ENABLE RELAY ENABLE RELAY
24VOPTIONAL 24V
PR
PR/BK
PR/BK
PR Y BL
TO TEST SWITCH
GROUND
SENSOR
CONNECTOR
RUNTIME
MONITORING RELAY
24V
R
4
2 5
1
AC POWER
CONNECTOR
6 PR/BK
3 PR/BK
BR
4
24V
GY
W1
W2
2
1
CN2
PR/BK
PR/BK
2-STAGE THERMOSTAT
RATIO
DISABLE
SHUTDOWN
O.A.
ENABLE
SENSOR
OPTIONAL
I/O RESET BOARD
BOILER ONLY
B
PR
PR
5
24VAC XFMR.
LINE
GY
GY
TH
SHUTDOWN
OPTIONAL
3
ON
CN7
4
OPERATOR
CN1
CN8
PUMP
ELECTRONIC
CONTROLLER
CN7
IGN1
IGN1
COM
+24
RST1
ALR
S2S2+
S2
S1
P1
WIRING BOX
CONNECTOR
120V
CONNECTION DIAGRAM A
Y
BR
O
BR
BR
GY
GY
Y
BL
BL/W
PR/BK
W
BK
R/BK
R
P
CONTROL BOX CONNECTIONS
WIRING DIAGRAM - CONTROL BOX CONNECTIONS
MODELS 985,000 - 2,065,000 BTU/HR
Revision 4 (CB-CW(E)-i&s-04) reflects changes made
to the O.A. section.
Revision 5 (CB-CW(E)-i&s-05) reflects changes made
to text on Page 21 and the LBLs on pages 47-51.
Revision 6 (ECO #C02870) reflects the addition of a
mixing valve to FIG. 41 (page 37) and edits made to the
scald warnings.
CB-CW(E)-i&s-06
CP-5M-1/09
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