A.O. Smith | BTH 400A | Operating instructions | A.O. Smith BTH 400A Operating instructions

CYCLONE XHE® Model BTH 300A AND 400A
Series 970
COMMERCIAL GAS WATER HEATER
GAS-FIRED POWER BURNER
FOR DOMESTIC HOT WATER
• INSTALLATION • OPERATION • SERVICE • MAINTENANCE • LIMITED WARRANTY
WARNING: If the information in these
instructions is not followed exactly, a fire
or explosion may result causing property
damage, personal injury or death.
– 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.
• 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.
Series 970
– Installation and service must be
performed by a qualified installer,
service agency or the gas supplier.
Thank you for buying this energy efficient water heater from
A.O. Smith Water Products Company. We appreciate your
confidence in our products.
CAUTION
TEXT PRINTED OR OUTLINED IN RED CONTAINS
INFORMATION RELATIVE TO YOUR SAFETY. PLEASE
READ THOROUGHLY BEFORE INSTALLING AND USING
THIS APPLIANCE.
A DIVISION OF A.O. SMITH CORPORATION
Mc BEE, SOUTH CAROLINA
STRATFORD (ONTARIO) CANADA
w w w.hotwater.com
PLACE THESE INSTRUCTIONS ADJACENT TO HEATER AND NOTIFY OWNER TO KEEP FOR FUTURE REFERENCE.
PRINTED IN U.S.A. 0306
PART NO. 197373-000
1
ROUGH-IN-DIMENSIONS
GAS VALVE PIPING
BTH-300
BTH-400
1 1/4" NPT
1 1/4" NPT
TABLE 1 RECOVERY CAPACITIES.
U.S. Gallons/Hr and Litres/Hr at TEMPERATURE RISE INDICATED
MODEL
TYPE OF
GAS
BTH-300
NATURAL
BTH-300
PROPANE
BTH-400
NATURAL
BTH-400
PROPANE
INPUT
BTUH
KW
300,000
88
280,000
82
400,000
117
400,000
117
Approx.
Capacity
130 US Gals.
492 Litres
130 US Gals.
492 Litres
130 US Gals.
492 Litres
130 US Gals.
492 Litres
F°
C°
GPH
LPH
GPH
LPH
GPH
LPH
GPH
LPH
20F°
11C°
1782
6745
1663
6295
2376
8993
2376
8993
30F°
17C°
1188
4496
1109
4197
1584
5995
1584
5995
40F°
22C°
891
3372
832
3148
1188
4496
1188
4496
50F°
28C°
713
2698
665
2518
950
3597
950
3597
60F°
33C°
594
2248
554
2098
792
2998
792
2998
70F° 80F° 90F°
39C° 44C° 50C°
509
445
396
1927 1686 1499
475
416
370
1799 1574 1399
679
594
528
2569 2248 1998
679
594
528
2569 2248 1998
100F°
56C°
356
1349
333
1259
475
1799
475
1799
110°
61C°
324
1226
302
1145
432
1635
432
1635
120F° 130F°
67C° 72C°
297
274
1124 1038
277
256
1049
968
396
366
1499 1384
396
366
1499 1384
140F°
78C°
255
964
238
899
339
1285
339
1285
Recovery capacities are based on heater performance at 98% thermal efficiency.
FOREWORD
In addition to these instructions, 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 should
be consulted before installations are made.
These designs comply with the current edition of the American
National Standard for Gas Water Heaters, Volume III,
ANSI Z21.10.3 / CSA 4.3 as an automatic circulating tank water
heater, and automatic storage water heaters.
Detailed installation diagrams are found in this manual. These
diagrams will serve to provide the installer with a reference for the
materials and methods of piping necessary. It is highly essential
that all water, gas piping and wiring be installed as shown on the
diagrams.
In the absence of local codes, the installation must comply
with the current editions of the National Fuel Gas Code,
ANSI Z223.1/NFPA 54 and the National Electrical Code,
NFPA 70 or CAN/CSA-B149.1, the Natural Gas and Propane
Installation Code and CSA C22.1, the Canadian Electrical Code.
All documents are available from the Canadian Standards
Association, 8501 East Pleasant Valley Road, Cleveland, OH 44131.
NFPA documents are also available from the National Fire
Protection Association, 1 Batterymarch Park, Quincy, MA 02269.
Particular attention should be given to the installation of
thermometers at the locations indicated on the diagrams as these
are necessary for checking the proper functioning of the heater.
2
TABLE OF CONTENTS
PAGE
ROUGH-IN DIMENSIONS ...................................................................
2
FOREWORD ......................................................................................
2
FEATURES ........................................................................................
3
Water Temperature Control .......................................................... 3-4
High Limit Switch (E.C.O.) ............................................................
4
Dishwashing Machine Requirement ............................................
4
Circulating Pump ...........................................................................
4
INSTALLATION INSTRUCTIONS ........................................................
4
Required Ability ............................................................................
4
Insulation Blankets ....................................................................... 4-5
Locating The Heater .....................................................................
5
Clearances ...................................................................................
5
Hard Water ...................................................................................
5
Air Requirements .........................................................................
6
Mechanical Exhausting of Room Air ............................................
6
Unconfined Space ........................................................................
6
Confined Space ............................................................................
6
Chemical Vapor Corrosion ...........................................................
6
VENTING ...........................................................................................
6
Vent Pipe Termination ...................................................................
6
Direct Venting ............................................................................... 7-8
Direct Vent Terminal Installation ...................................................
8
Installation Sequence ................................................................... 8-9
Vertical Vent Terminal Installation ................................................
9
Installation Sequence ...................................................................
9
Installation of Vent System ..........................................................
10
Vent Pipe Preparation ................................................................... 10-11
CONTROLS AND SWITCHES ............................................................
11
Blower Prover Switch .................................................................
11
Blocked Outlet Prover Switch ......................................................
11
Blocked Inlet Prover Switch .........................................................
11
Low Gas Pressure Switch ..........................................................
11
On/Off Switch ..............................................................................
11
Hot Surface Igniter .......................................................................
11
GAS PIPING .......................................................................................
12
Connection of Gas Pipe ............................................................... 12-13
Purging .........................................................................................
13
Gas Meter Size - City Gases Only ..............................................
13
Gas Pressure Regulation .............................................................
13
Gas Valves ...................................................................................
13
SYSTEM CONNECTIONS ..................................................................
13
Thermometers ..............................................................................
13
Relief Valve ..................................................................................
13
Water Line Connections ..............................................................
13
PAGE
Closed System ................................................................................ 13
Water (Potable) Heating & Space Heating ...................................... 13
Heater Wiring .................................................................................. 14-15
OPERATION .......................................................................................... 15
Sequence of Operation .................................................................. 15
Self Diagnostic Controller ............................................................... 15
Gas Value LEDs Flashing ............................................................... 15
Error Codes ..................................................................................... 16
Fault Conditions ............................................................................... 16
No Incoming Line Voltage ................................................................ 16
No Low Voltage .......................................................................... 16
Temperature Probe Fault ................................................................. 16
E.C.O. Switch Open ........................................................................ 17
Control Bad ...................................................................................... 17
Combustion Air Blockage ................................................................ 17
PRIOR TO START-UP ........................................................................... 18
Required Ability ............................................................................... 18
OPERATING INSTRUCTIONS ................................................................ 18
Adjustment Procedure (Initial Start-Up) .......................................... 18
Lighting Instructions ........................................................................ 19
Cathodic Protection ......................................................................... 20
Precautions ..................................................................................... 20
GENERAL INFORMATION .................................................................... 20
Power Burner ................................................................................. 20
High Limit ......................................................................................... 20
High Altitude Installations ................................................................ 20
MAINTENANCE .................................................................................... 20
General ............................................................................................ 20
Maintenance Schedule ................................................................... 20
Flushing ........................................................................................... 21
Draining ........................................................................................... 21
Sediment Removal ........................................................................... 21
Lime Scale Removal ........................................................................ 21
Powered Anode System ................................................................. 21-22
Drain Valve and Access Panels ..................................................... 22
Relief Valve ..................................................................................... 22
Internal Circulating Pump ................................................................. 22
Vent System .................................................................................... 22
INSTALLATION DIAGRAMS ................................................................. 23-27
Manifold Kits .................................................................................... 28
CHECKLIST AND SERVICE INFORMATION .......................................... 29
TROUBLE-SHOOTING .......................................................................... 29-30
REPLACEMENT PARTS ........................................................................ 30
LIMITED WARRANTY ........................................................................... 31
FEATURES
IMPORTANT
DANGER
IT IS REQUIRED THAT A QUALIFIED SERVICE TECHNICIAN
PERFORM THE INITIAL FIRING OF THE HEATER. AT THIS TIME
THE USER SHOULD NOT HESITATE TO ASK THE TECHNICIAN
ANY QUESTIONS WHICH HE MAY HAVE IN REGARD TO THE
OPERATION AND MAINTENANCE OF THE UNIT.
THIS WATER HEATER IS EQUIPPED WITH AN ADJUSTABLE
THERMOSTAT TO CONTROL WATER TEMPERATURE. HOT
WATER TEMPERATURES REQUIRED FOR AUTOMATIC
DISHWASHER AND LAUNDRY USE CAN CAUSE SCALD BURNS
RESULTING IN SERIOUS PERSONAL INJURY AND/OR DEATH.
THE TEMPERATURE AT WHICH INJURY OCCURS VARIES WITH
THE PERSON’S AGE AND TIME OF EXPOSURE. THE SLOWER
RESPONSE TIME OF CHILDREN, AGED OR DISABLED
PERSONS INCREASES THE HAZARDS TO THEM. NEVER
ALLOW SMALL CHILDREN TO USE A HOT WATER TAP, OR TO
DRAW THEIR OWN BATH WATER. NEVER LEAVE A CHILD OR
DISABLED PERSON UNATTENDED IN A BATHTUB OR
SHOWER.
A CHECKLIST AND SERVICE INFORMATION section are included
at the rear of this manual. By using this checklist the user may be
able to make minor operational adjustments and save himself
unnecessary service calls. However, the user should not attempt
repairs which are not listed in this section.
WATER TEMPERATURE CONTROL
THE WATER HEATER SHOULD BE LOCATED IN AN AREA
WHERE THE GENERAL PUBLIC DOES NOT HAVE ACCESS TO
SET TEMPERATURES.
The water temperature is controlled using the Temperature Control
Button on the Display at the front of the unit (See Figure 1). This
control utilizes two temperature probes to determine the tank
temperature. The primary temperature probe is located at the top
of the tank and the other is near the water inlet.
3
“AT A GLANCE” BTH 300/400
QUICK INSTALLATION TIPS
Horizontal Sidewall Venting
Vertical Rooftop Venting
4
The temperature may be adjusted from 80°F/27°C to 180°F/82°C.
The thermostat was adjusted to 120°F/49°C before the heater
was shipped from the factory. It is recommended that lower water
temperatures be used to avoid the risk of scalding. It is further
recommended, in all cases, that the water temperature be set for
the lowest temperature which satisfies your hot water needs.
This will also provide the most energy efficient operation of the
water heater and minimize scale formation.
Valves for reducing point-of-use temperature by mixing cold and
hot water are available (see Figure 2). Also available are
inexpensive devices that attach to faucets to limit hot water
temperatures. Contact a licensed plumber or the local plumbing
authority.
WATER TEMPERATURE SETPOINT
ADJUSTMENT PROCEDURE
CAUTION
THE TEMPERATURE OF THE WATER AT THE TANK OUTLET MAY
NOT CORRESPOND TO THE TEMPERATURE SETPOINT
PROGRAMMED IN THE CONTROLLER. THE USER CAN EASILY
CHANGE THE TEMPERATURE SETPOINT AT ANY TIME BY USING
THE FOLLOWING PROCEDURE. IN ALL CASES, INPUT POWER
MUST BE APPLIED TO THE CONTROLLER TO PERFORM ANY
PROGRAMMING OPERATIONS.
FIGURE 2.
To change or view the current programmed temperature setpoint
value, utilize the pushbutton on the Display Board. Momentarily
pressing the button will briefly illustrate the existing setpoint value.
If the button is held down for more than one second, the
programming mode is automatically entered and the setpoint value
will begin incrementing or decrementing by one degree per second.
The control will alternate between between the incrementing or
decrementing mode each time the button is pressed. When the
desired setpoint value is reached, simply release the button and
the controller will automatically retain this value in temporary
memory. After one complete heat cycle, the new setpoint is
transferred to permanent memory.
HIGH LIMIT SWITCH (E.C.O.)
The top immersion well of the dual bulb controller also contains
the high limit (energy cutoff) sensor. The high limit switch interrupts
the main burner gas flow should the water temperature reach
approximately 202°F/94°C.
Should the high limit switch activate, it must be manually reset by
depressing the Temperature Adjustment Button/Reset Button on
the display board. The water temperature must drop below 160°F/
71°C before the controller can be reset.
Note: If power is interrupted prior to completing one heat cycle, the
new setpoint will not be transferred to permanent memory.
Therefore, it is a good practice to recheck the setpoint value at the
end of a heat cycle after a new value has been entered.
Continued manual resetting of high limit control, preceded by
higher than usual water temperature is evidence of high limit switch
operation. The following is a possible reason for high limit switch
operation.
If the button is held down long enough, the setpoint will reach 70°F
(the minimum value) and stop. At this point, if the desired setpoint
has not been obtained, release the button and depress it again.
The setpoint value will now restart at 70°F and once again increase
in value for as long as the button is pressed.
• A malfunction in the thermostatic controls would allow the gas
valve to remain open causing water temperature to exceed the
thermostat setting. The water temperature would continue to
rise until high limit switch operation.
Contact your dealer or servicer if continued high limit switch
operation occurs.
Figure 1 shows the approximate time-to-burn relationship for normal
adult skin. Short repeated heating cycles caused by small hot water
uses can cause temperatures at the point of use to exceed the thermostat
setting by up to 20°F (11C°). If you experience this type of use, you should
consider using lower temperature settings to reduce scald hazards.
Temperature
Setting
180°F / 82°C
170°F / 77°C
160°F / 71°C
150°F / 66°C
140°F / 60°C
130°F / 54°C
120°F / 49°C
DISHWASHING MACHINE REQUIREMENT
All dishwashing machines meeting the National Sanitation
Foundation requirements are designed to operate with water flow
pressures between 15 and 25 pounds per square inch (103 Kpa
and 173 Kpa). Flow pressures above 25 pounds per square inch
(173 Kpa), or below 15 pounds per square inch (103 Kpa), will
result in improperly sanitized dishes. Where pressures are high, a
water pressure reducing or flow regulating control valve should be
used in the 180°F (82°C) line to the dishwashing machine, and
should be adjusted to deliver water between these limits.
Time to Produce 2nd & 3rd
Degree Burns on Adult Skin
Nearly instantaneous
Nearly instantaneous
About 1/2 second
About 1-1/2 seconds
Less than 5 seconds
About 30 seconds
More than 5 minutes
The National Sanitation Foundation also recommends circulation
of 180°F (82°C) water. Where this is done, the circulation should
be very gentle so that it does not cause any unnecessary turbulence
inside the water heater. The circulation should be just enough to
provide 180°F (82°C) water at the point of take-off to the dishwashing
machine. Adjust flow by means of the plug cock in the circulating
line. (See installation diagrams.)
FIGURE 1.
5
THE HEATER SHALL BE LOCATED OR PROTECTED SO IT IS
NOT SUBJECT TO PHYSICAL DAMAGE BY A MOVING VEHICLE.
CIRCULATING PUMP
A circulating pump is used when a system requires a circulating loop
or there is a storage tank used in conjunction with the heater. Refer to
the piping diagrams at rear of manual for electrical hookup information
and install in accordance with the current edition of the National
Electrical Code, NFPA 70 or the Canadian Electrical Code, CSA C22.1.
DO NOT LOCATE THE HEATER WHERE NOISE FROM THE
EXHAUST OR INTAKE WILL BE OBJECTIONABLE. THIS
INCLUDES LOCATIONS CLOSE TO OR ACROSS FROM
WINDOWS AND DOORS. AVOID ANCHORING THE VENT AND
INTAKE PIPES DIRECTLY TO FRAMED WALLS, FLOORS OF
CEILINGS UNLESS RUBBER ISOLATION PIPE HANGERS ARE
USED. THIS PREVENTS ANY VIBRATIONS FROM BEING
TRANSMITTED INTO THE LIVING SPACES.
All bronze circulators are recommended for used with commercial
water heaters.
Although circulators are oiled and operated by the manufacturer
some circulators must be oiled again before operated. Please refer
to manufacturer's instructions.
WARNING
REQUIRED ABILITY
FLAMMABLE ITEMS, PRESSURIZED CONTAINERS OR ANY
OTHER POTENTIAL FIRE HAZARDOUS ARTICLES MUST NEVER
BE PLACED ON OR ADJACENT TO THE HEATER. OPEN
CONTAINERS OF FLAMMABLE MATERIAL SHOULD NOT BE
STORED OR USED IN THE SAME ROOM WITH THE HEATER.
INSTALLATION OR SERVICE OF THIS WATER HEATER
REQUIRES ABILITY EQUIVALENT TO THAT OF A LICENSED
TRADESMAN IN THE FIELD INVOLVED. PLUMBING, AIR
SUPPLY, VENTING, GAS SUPPLY AND ELECTRICAL WORK ARE
REQUIRED.
When installing the heater, consideration must be given to proper
location. Location selected should be as close to the intake
and exhaust termination points as practicable, with adequate
air supply and as centralized with the piping system as
possible.
INSULATION BLANKETS
THE HEATER MUST NOT BE LOCATED IN AN AREA WHERE IT
WILL BE SUBJECT TO FREEZING.
INSTALLATION INSTRUCTIONS
Insulation blankets available to the general public for external
use on gas water heaters are not approved for use on your A.O.
Smith water heater. The purpose of an insulation blanket is to
reduce the standby heat loss encountered with storage tank water
heaters. Your A.O. Smith water heater meets or exceeds the
ASHRAE/IES 90.1-1999 standards with respect to insulation and
standby loss requirements, making an insulation blanket
unnecessary.
LOCATE IT NEAR A FLOOR DRAIN. THE HEATER SHOULD BE
LOCATED IN AN AREA WHERE LEAKAGE FROM THE HEATER
OR CONNECTIONS WILL NOT RESULT IN DAMAGE TO THE
ADJACENT AREA OR TO LOWER FLOORS OF THE
STRUCTURE.
When such locations cannot be avoided, it is recommended that a
suitable drain pan, adequately drained, be installed under the
appliance.
WARNING
Should you choose to apply an insulation blanket to this heater,
you should follow these instructions. Failure to follow these
instructions can result in fire, asphyxiation, serious personal injury
or death.
WARNING
THIS WATER HEATER IS A CONDENSING UNIT AND REQUIRES
A DRAIN TO BE LOCATED IN CLOSE PROXIMITY TO ALLOW
THE CONDENSATE TO DRAIN SAFELY. THE CONDENSATE
DRAINS FROM THE UNIT AT THE EXHAUST ELBOW LOCATED
AT THE BOTTOM OF THE UNIT. NOTE: IT IS IMPORTANT THAT
THE CONDENSATE HOSE NOT BE ELEVATED ABOVE THE
EXHAUST ELBOW (SEE FIGURE 3). THE CONDENSATE BUILDUP WILL BLOCK THE EXHAUST OUTLET, WHICH WILL CAUSE
IMPROPER OPERATION.
• Do not apply insulation to the top, or the upper 15" (38 cm) of
the water heater, as this will interfere with safe operation.
• Do not cover the temperature & pressure relief valve.
• Do not cover the instruction manual. Keep it on the side of the
water heater or nearby for future reference.
• Do obtain new labels from A.O. Smith for placement on the
blanket directly over the existing labels.
LOCATING THE HEATER
WARNING
THERE IS A RISK IN USING FUEL BURNING APPLIANCES SUCH
AS GAS WATER HEATERS IN ROOMS, GARAGES OR OTHER
AREAS WHERE GASOLINE, OTHER FLAMMABLE LIQUIDS OR
ENGINE DRIVEN EQUIPMENT OR VEHICLES ARE STORED,
OPERATED OR REPAIRED. FLAMMABLE VAPORS ARE HEAVY
AND TRAVEL ALONG THE FLOOR AND MAY BE IGNITED BY THE
HEATER’S IGNITER OR MAIN BURNER FLAMES CAUSING FIRE
OR EXPLOSION. SOME LOCAL CODES PERMIT OPERATION OF
GAS APPLIANCES IF INSTALLED 18 INCHES (46 cm) OR MORE
ABOVE THE FLOOR. THIS MAY REDUCE THE RISK IF LOCATION
IN SUCH AN AREA CANNOT BE AVOIDED.
FIGURE 3.
WARNING
DO NOT USE THIS APPLIANCE IF ANY PART HAS BEEN UNDER
WATER. IMMEDIATELY CALL A QUALIFIED SERVICE
TECHNICIAN TO INSPECT THE APPLIANCE AND TO REPLACE
ANY PART OF THE CONTROL SYSTEM AND ANY GAS
CONTROL WHICH HAS BEEN UNDER WATER.
6
SERIOUS DAMAGE TO THE HEATER AND RISK OF FIRE OR
EXPLOSION. IT CAN ALSO CREATE A RISK OF ASPHYXIATION.
CLEARANCES
These heaters are approved for installation on combustible flooring
in an alcove when the minimum clearances from any combustion
construction are followed as indicated in Figure 4.
UNCONFINED SPACE
In all installations the minimum combustible clearances from any
vent piping shall be 0". Vent piping passing through a combustible
wall or ceiling must be a continuous run (no joints).
In buildings of conventional frame, brick or stone construction,
unconfined spaces may provide adequate air for combustion and
ventilation.
A service clearance of 24" (61 cm) should be maintained from
serviceable parts such as relief valves, thermostats, cleanout
openings, drain valves and venting connections.
If the unconfined space is within a building of tight construction
(buildings using the following construction: weather stripping, heavy
insulation, caulking, vapor barrier, etc.), air for combustion and
ventilation must be obtained from outdoors. The installation
instructions for confined spaces in tightly constructed buildings
must be followed to ensure adequate air supply.
Always disconnect electrical power before servicing the unit
CONFINED SPACE
When drawing combustion air from inside a conventionally
constructed building to a confined space, such a space shall be
provided with two permanent openings, ONE IN OR WITHIN
12 INCHES (31 cm) OF THE ENCLOSURE TOP AND ONE IN OR
WITHIN 12 INCHES (31 cm) OF THE ENCLOSURE BOTTOM.
Each opening shall have a free area of at least one square inch per
1000 Btuh (2,203mm2/kW) appliances in the enclosure, but not
less than 100 square inches (645 cm²).
*ILLUSTRATION OF MINIMUM COMBUSTIBLE CLEARANCES IN AN ALCOVE.
FIGURE 4.
See MAINTENANCE section for details of tank cleanout procedure.
If the confined space is within a building of tight construction, air for
combustion and ventilation must be obtained from outdoors. When
directly communicating with the outdoors through vertical ducts, two
permanent openings, located in the above manner, shall be provided.
Each opening shall have a free area of not less than one square inch
per 4000 Btuh (551mm2/kW) of the total input of all appliances in the
enclosure. If horizontal ducts are used, each opening shall have a
free area of not less than one square inch per
2000 Btuh (1,102mm2/kW) of the total input of all appliances in the
enclosure.
AIR REQUIREMENTS
CHEMICAL VAPOR CORROSION
HARD WATER
Where hard water conditions exist, water softening or the threshold
type of water treatment is recommended. This will protect the
dishwashers, coffee urns, water heaters, water piping and other
equipment.
WARNING
KEEP APPLIANCE AREA CLEAR AND FREE OF COMBUSTIBLE
MATERIALS, GASOLINE AND OTHER FLAMMABLE VAPORS AND
LIQUIDS.
CORROSION OF THE FLUE WAYS AND VENT SYSTEM MAY
OCCUR IF AIR FOR COMBUSTION CONTAINS CERTAIN
CHEMICAL VAPORS. SUCH CORROSION MAY RESULT IN
FAILURE AND RISK OF ASPHYXIATION.
DO NOT OBSTRUCT THE FLOW OF COMBUSTION AND
VENTILATING AIR.
Spray can propellants, cleaning solvents, refrigerator and air
conditioning refrigerants, swimming pool chemicals, calcium and
sodium chloride, waxes, and process chemicals are typical
compounds which are potentially corrosive.
WARNING
FOR SAFE OPERATION PROVIDE ADEQUATE AIR FOR
COMBUSTION AND VENTILATION. AN INSUFFICIENT SUPPLY
OF AIR WILL CAUSE RECIRCULATION OF COMBUSTION
PRODUCTS RESULTING IN CONTAMINATION THAT MAY BE
HAZARDOUS TO LIFE. SUCH A CONDITION OFTEN WILL RESULT
IN A YELLOW, LUMINOUS BURNER FLAME, CAUSING CARBONING
OR SOOTING OF THE COMBUSTION CHAMBER, BURNERS AND
FLUE TUBES AND CREATES A RISK OF ASPHYXIATION.
PRODUCTS OF THIS SORT SHOULD NOT BE STORED NEAR
THE HEATER. ALSO, AIR WHICH IS BROUGHT IN CONTACT WITH
THE HEATER SHOULD NOT CONTAIN ANY OF THESE
CHEMICALS. IF NECESSARY, UNCONTAMINATED AIR SHOULD
BE OBTAINED FROM REMOTE OR OUTSIDE SOURCES.
MECHANICAL EXHAUSTING OF ROOM AIR
VENTING
Where an exhaust fan is installed in the same room with a heater,
sufficient openings for air must be provided in the walls.
UNDERSIZED OPENINGS WILL CAUSE AIR TO BE DRAWN
INTO THE ROOM THROUGH THE HEATER’S VENTING SYSTEM,
CAUSING POOR COMBUSTION. SOOTING MAY RESULT IN
THE INSTRUCTIONS IN THIS SECTION ON VENTING MUST BE
FOLLOWED TO AVOID CHOKED COMBUSTION OR
RECIRCULATION OF FLUE GASES. SUCH CONDITIONS CAUSE
SOOTING OR RISKS OF FIRE AND ASPHYXIATION.
WARNING
7
US DIRECT VENT
CAUTION
TO PREVENT EXHAUSTING PRODUCTS FROM CIRCULATING TO THE
AIR INTAKE IN WINDY/COLD AREAS, THE MAXIMUM PRACTICAL
DISTANCE BETWEEN THESE TWO TERMINALS IS RECOMMENDED.
CANADIAN DIRECT VENT
FIGURE 5.
8
US HORIZONTAL VENT
CAUTION
TO PREVENT EXHAUSTING PRODUCTS FROM CIRCULATING TO THE
AIR INTAKE IN WINDY/COLD AREAS, THE MAXIMUM PRACTICAL
DISTANCE BETWEEN THESE TWO TERMINALS IS RECOMMENDED.
CANADIAN HORIZONTAL VENT
FIGURE 6.
9
Heater must be protected from freezing downdrafts during
shutdown periods.
3"x 4" 45° PVC ELBOW WITH INTAKE GUARD
WARNING
NEVER OPERATE THE HEATER UNLESS IT IS VENTED TO
THE OUTDOORS AND HAS ADEQUATE AIR SUPPLY TO AVOID
RISKS OF IMPROPER OPERATION, FIRE, EXPLOSION OR
ASPHYXIATION.
FIGURE 7.
VENT PIPE TERMINATION
NOTE: Before installing venting, determine place of vent pipe
termination. See Figure 5 and 6 before proceeding.
WARNING
WHEN THE UNIT IS TO BE SETUP AS A DIRECT VENT, THE INTAKE
GUARD MUST BE REMOVED. THE INLET VENT PIPE MAY THEN
BE GLUED TO THE AIR INTAKE (see Figure 8) PROVIDED ON
THE UNIT.
CAUTION
DO NOT TERMINATE THE VENTING WHERE NOISE FROM THE
EXHAUST OR INTAKE WILL BE OBJECTIONABLE. THIS
INCLUDES LOCATIONS CLOSE TO OR ACROSS FROM WINDOWS
AND DOORS. AVOID ANCHORING THE VENT AND INTAKE PIPES
DIRECTLY TO FRAMED WALLS, FLOORS OR CEILINGS UNLESS
RUBBER ISOLATION PIPE HANGERS ARE USED. THIS
PREVENTS ANY VIBRATIONS FROM BEING TRANSMITTED INTO
THE LIVING SPACES.
IMPORTANT
The vent system must terminate so that proper clearances are
maintained as cited in local codes or the current editions of
the National Fuel Gas Code, ANSI Z223.1/NFPA 54 or the
Canadian Electrical Code, CSA C22.1.
Do not terminate the exhaust vent terminal over public area where
condensate or vapor can cause nuisance or hazard.
FIGURE 8.
Plan the vent system layout so that proper clearances are
maintained from plumbing and wiring.
DIRECT VENT TERMINAL INSTALLATION
Vent pipes serving power vented appliances are classified by
building codes as "vent connectors". Required clearances from
combustible materials must be provided in accordance with
information in this manual under LOCATION OF HEATER and
CLEARANCES, and with National Fuel Gas Code and local Codes.
IMPORTANT
THIS UNIT CONSISTS OF TWO VENT TERMINALS - AN INTAKE
VENT TERMINAL AND AN EXHAUST VENT TERMINAL. THE INTAKE
VENT TERMINAL IS A 3" 45° PVC ELBOW WITH A DOME SHAPE
SCREEN AND THE EXHAUST VENT TERMINAL IS A 3" 45°PVC
ELBOW WITH A MESH WIRE SCREEN.
IMPORTANT
NOTE: TO PREVENT EXHAUSTING PRODUCTS FROM
CIRCULATING TO THE AIR INTAKE IN WINDY/COLD AREAS, THE
MAXIMUM PRACTICAL DISTANCE BETWEEN THESE TWO
TERMINALS IS RECOMMENDED.
Plan the layout of the vent system backwards from the vent
termination to the appliance.
IMPORTANT
WARNING
USE ONLY THE VENT TERMINALS SUPPLIED WITH THIS UNIT.
TERMINATION OF A VENT SYSTEM WITH A DEVICE OTHER THAN
THE SUPPLIED VENT TERMINATIONS WILL AFFECT SYSTEM
PERFORMANCE AND RESULT IN A SAFETY HAZARD.
WHEN LOCATING THE TERMINALS ON A SIDEWALL, THE
FOLLOWING SPECIFICATIONS PERTAINING TO TERMINAL
LOCATION MUST BE FOLLOWED.
1. The intake vent terminal and the exhaust vent terminal must
terminate on the same exterior wall and must be located at a
minimum of 24" (61cm) from the vertical centerline of the exhaust
vent terminal (see Figure 9). In colder climates increasing the
24" (61cm) minimum to 48" (122cm) will reduce possibility of
frost over from side winds blowing exhaust vapors to the air
intake of the direct the vent and is recommended for Canada.
DIRECT VENTING
The air intake provided on the unit contains an intake guard,
see Figure 7.
10
Slide the pipe through the wall and insert into coupling on the
other side of the wall, making sure that the vent terminal ends
up pointed in the correct position. See Figure 10.
2. The horizontal centerline of the intake vent terminal may not be
located lower than the horizontal centerline of the exhaust vent
terminal (see Figure 9).
EXHAUST VENT TERMINAL
FIGURE 9.
INSTALLATION SEQUENCE
For installations in the City of Los Angeles, California Category IV
PVC Pipe such as that manufactured by Brownline Pipe Company,
must be used as vent pipe material.
CAUTION
Vent terminals supplied with the heater must be used.
NOTE: BEFORE BEGINNING INSTALLATION OF ANY VENT PIPE
READ THE VENT PIPE MANUFACTURER'S INSTALLATION
INSTRUCTIONS.
INTAKE VENT TERMINAL
1. After the points of termination have been determined, use the
cover plates as templates to mark the holes for the vent pipes to
be inserted through the wall. BEWARE OF CONCEALED
WIRING AND PIPING INSIDE OF WALL.
2. If the vent terminals are being installed on the outside of a
finished wall, it may be easier to mark both the inside and outside
wall. Align the holes by drilling a hole through the center of the
template from the inside through to the outside. The template
can now be positioned on the outside wall using the drilled
holes as a centering point for the template.
3. A) MASONRY SIDE WALLS
Chisel an opening approximately 1/2" (1.3 cm) larger than the
marked circle.
B) WOODEN SIDE WALLS
Drill a pilot hole approximately one quarter inch outside of the
marked circle. This pilot hole is used as a starting point for a
saws-all or sabre saw blade. Cut around the marked circle
staying approximately one quarter inch outside of the line. (This
will allow the vent pipe to easily slide through the opening. The
resulting gap will be covered by the vent terminal cover plates.)
Repeat this step on the inside wall if necessary.
4. Cut a length of PVC pipe about 3.5" (8.9 cm) longer than the wall
thickness at the opening.
5. Glue the intake vent terminal to the section of the pipe.
FIGURE 10.
VERTICAL VENT TERMINAL INSTALLATION
IMPORTANT
WHEN TERMINATING THROUGH A ROOF, THE FOLLOWING
SPECIFICATIONS PERTAINING TO TERMINAL LOCATION MUST
BE FOLLOWED.
1. Proper support must be provided for all pipe protruding through
the roof.
2. The vertical roof terminations should be sealed with a plumbing
roof boot or equivalent flashing.
3. The intake vent termination and the exhaust vent termination
must penetrate the same side of roof.
4. The center line of the intake vent termination and the center line
of the exhaust vent termination must be no closer than
24" (61cm).
5. The intake vent terminal and the exhaust vent terminal must be
oriented facing downward and the same direction.
The specifications are displayed in Figure 11.
NOTE: Exhaust vent terminal is installed using the same procedure.
6. Slide the wall plate over the pipe to stop against intake vent terminal.
INSTALLATION SEQUENCE
7. Place a bead of caulking (not supplied) around the gap between
the pipe and the wall. Place some of the caulking on the back of
the plate to hold it against the wall after installation.
NOTE: BEFORE BEGINNING INSTALLATION OF ANY VENT PIPE,
READ “VENT PIPE PREPARATION” SECTION ON PAGE 12.
8. If the vent pipe is installed up to the wall, with a coupling on the
end against the wall opening, the pipe with the vent terminal
can be prepared for gluing before inserting through the wall.
1. After the points of termination have been determined, use the
cover plates as templates to mark the holes for the vent pipes
to be inserted through the roof.
11
2. Drill a pilot hole approximately 1/4" (6 mm) outside of the marked
circle. This pilot hole is used as a starting point for a saws-all or
sabre saw blade. Cut around the marked circle staying
approximately one quarter inch outside the line. (This will allow
the vent pipe to easily slide through the opening). The resulting
gap will be covered by the roof boot/flashing.
minimum amount of pipe required for the exhaust venting
arrangement. The intake venting arrangement is certified to
use a minimum of 0-equivalent feet of 4-inch PVC pipe.
4. The 3-inch PVC terminals supplied with the unit must be used
with the 4-inch venting by adding a 4" x 3" reducer coupling at
the venting terminals.
3. Suspend the pipe through center of hole using proper support.
IMPORTANT
When multiple units are direct vented through a wall (4-inch venting),
all intake vent terminals should be no lower than the highest
exhaust vent terminal.
4. Slide roof boot or equivalent flashing over pipe and secure roof
boot equivalent flashing to roof.
5. Seal around flashing.
6. Terminate intake terminal and exhaust vent terminal facing
down. See Figure 11.
NOTE: This unit can be vented using only PVC (Class 160, ASTM
D-2241 Schedule 40, ASTM D-1785 ; or Cellular Core Schedule
40 DWV, ASTM F-891) , Schedule 40 CPVC (ASTM F-411), or ABS
(ASTM D-2661) pipe. The fittings, other than the TERMINATIONS
should be equivalent to PVC-DWV fittings meeting ASTM D-2665
(Use CPVC fittings, ASTM F-438 for CPVC pipe and ABS fittings,
ASTM D-2661/3311 for ABS pipe. If CPVC or ABS pipe and fittings
are used, then the proper cement must be used for all joints,
including joining the pipe to the Termination (PVC Material). PVC
Materials should use ASTM D-2564 Grade Cement; CPVC
Materials should use ASTM F-493 Grade Cement and ; ABS
Materials should use ASTM D-2235 Grade Cement.
NOTE: for Water Heaters in locations with high ambient
temperatures (above 100°F or 38°C) and/or insufficient dilution
air, it is recommended that CPVC or ABS pipe and fittings (MUST
USE SUPPLIED VENT TERMINAL) be used.
FIGURE 11.
5. It is important that condensate not be allowed to buildup in the
exhaust vent pipe. To prevent this from happening the pipe
should be installed with a slight, 1/8 inch (3mm) per 5 feet (152
cm) of pipe maximum downward slope.
INSTALLATION OF VENT SYSTEM
WARNING
THE OPTIONAL INTAKE VENTING ARRANGEMENT AND THE
EXHAUST VENTING ARRANGEMENT MUST BE INSTALLED TO
RUN DIRECTLY TO THE OUTDOORS AND NOT IN ANY WAY BE
CONNECTED TO ANOTHER VENTING SYSTEM (I.E. FURNACE,
DRYERS OR SPACE HEATERS). IT IS CRUCIAL THAT THE
VENTING ARRANGEMENT BE KEPT SEPARATE FROM OTHER
VENTING SYSTEMS. IF THIS WARNING IS IGNORED, AND THE
SYSTEM IS VENTED INCORRECTLY, IT MAY CAUSE IMPROPER
OPERATION, FIRE, EXPLOSION, OR ASPHYXIATION.
6. The vent system should be supported every 5 feet (152 cm) of
vertical run and every 3 feet (91cm) of horizontal run of vent
pipe length.
NOTE: Stress levels in the pipe and fittings can be significantly
increased by improper installation. If rigid pipe clamps are used to
hold the pipe in place, or if the pipe cannot move freely through a
wall penetration, the pipe may be directly stressed, or high thermal
stresses may be formed when the pipe heats up and expands.
Install accordingly to minimize such stresses.
1. Plan the route of the vent system from the vent termination to
the planned location of the appliance. Layout the total vent
system to use the minimum of vent pipe and elbows possible.
2. This unit is certified for the use of 4-inch PVC pipe for venting. The
maximum length of 80-equivalent feet of 4-inch PVC pipe may be
used for the intake venting arrangement and a maximum length of
80-equivalent feet of 4-inch PVC pipe may be used on the exhaust
venting arrangement. The maximum number of 90 degree elbows
for the 4-inch venting is six (6) in the intake and six (6) on the exhaust.
A 90 degree elbow is equal to five (5) equivalent feet of 4-inch pipe.
One 90 degree elbow is equaled to two 45 degree elbows.
INLET VIEW
Table 2. VENT LENGTH TABLE
Number
of 90°
Elbows
ONE (1)
TWO (2)
THREE (3)
FOUR (4)
FIVE (5)
SIX (6)
4" PVC
Maximum
Feet. of Pipe
75'
70'
65'
60'
55'
50'
Maximum
Meters of Pipe
22.9 m
21.3 m
19.8 m
18.3 m
16.8 m
15.2 m
OUTLET VIEW
3. The unit is certified to a minimum amount of 4-inch pipe for the
exhaust venting arrangement of 15-equivalent feet. This is the
FIGURE 12.
12
VENT PIPE PREPARATION
1. INITIAL PREPARATION
A. Make sure the solvent cement you are planning to use is
designed for the specific application you are attempting.
B. Know the physical and chemical characteristics and
limitations of the PVC, PVC cellular core, ABS or CPVC
piping materials that you are about to use.
C. Know the reputation of your pipe and cement manufacturer
and their products.
D. Know your own qualifications or those of your contractor.
The solvent welding technique of joining PVC, PVC cellular
core, ABS or CPVC pipe is a specialized skill just as any
other pipe fitting technique.
E. Closely supervise the installation and inspect the finished
job before start-up.
F.
Contact the manufacturer, supplier, or competent consulting
agency if you have any questions about the application or
installation of PVC, PVC cellular core, ABS or CPVC pipe.
G. Take the time and effort to do a professional job. Shortcuts
will only cause you problems and delays in start-up. The
majority of failures in these systems are the result of
shortcuts and/or improper joining techniques.
2. SELECTION OF MATERIALS
PRIMER
It is recommended that Tetrahydrofuran (THF) be used to prepare
the surfaces of pipe and fittings for solvent welding. Do not use
water, rags, gasoline or any other substitutes for cleaning PVC
cellular core, ABS or CPVC surfaces. A chemical cleaner such as
MEK may be used.
to close. The pressure switch is connected to the burner tap by a
piece of tygon tubing. This tubing must be connected in order for
the switch to change the electrical contacts. The controller requires
that the electrical contacts on this air flow switch be open before it
will allow the blower to come on. See Figure 13.
BLOCKED OUTLET PROVER SWITCH
The Blocked Outlet Prover Switch is set up to shut the unit off
when a build-up of positive pressure in the exhaust vent pipe
occurs. This switch is a positive pressure switch that requires an
increase in pressure to change the electrical contacts from
normally closed to open. When this switch prevents the unit from
igniting, most likely the exhaust is blocked by some means. Check
to see if the condensate is allowed to flow freely from the exhaust
elbow and for obstructions in the exhaust venting and exhaust
vent terminal. See Figure 13.
BLOCKED INLET PROVER SWITCH
The Blocked Inlet Prover Switch is set up to shut the unit off when
a build-up of negative pressure in the intake vent pipe occurs. This
switch is a negative pressure switch that requires an increase in
negative pressure to change the electrical contacts from normally
closed to open. The switch is connected to the pressure tap on the
flange connected to the inlet of the blower. When this switch
prevents the unit from igniting, most likely the intake is blocked by
some means. Check to see if there is no more than eighty (80)
equivalent feet (24.8m) of four inch PVC vent pipe on the intake. Also
verify that the intake and intake vent terminal is free of obstructions
that may prevent air from entering the unit. See Figure 13.
LOW GAS PRESSURE SWITCH
The Low Gas Switch (LGS) is a single-pole, normally open
pressure switch that will close its contacts when a rising pressure
of 5.0 in. W.C. (1.25Kpa) is encountered. The contacts will open
when the pressure falls below the fixed set point of 5.0 in. W.C.
(1.25Kpa) The LGS monitors the gas supply pressure to the heater.
If the gas supply falls below 5.0 in. W.C. (1.25Kpa), the main
burner is extinguished (if heater is running) or the heater will not
start up. NOTE: LOW GAS IS LOCATED ON INLET SIDE OF GAS
VALVE. See Figure 13.
CEMENT
The cement should be a bodied cement of approximately 500 to
1600 centipoise viscosity containing 10-20% (by weight) virgin PVC
material solvated with tetrahydrofuran (THF). Small quantities of
dimethyl formamide (DMF) may be included to act as a retarding
agent to extend curing time. Select the proper cement; Schedule
40 cement should be used for Schedule 40 pipe. Never use
all-purpose cements, commercial glues and adhesives or
ABS cement to join PVC or CPVC pipe and fittings.
SAFETY PRECAUTION: PRIMERS AND CEMENTS ARE
EXTREMELY FLAMMABLE AND MUST NOT BE STORED OR USED
NEAR HEAT OR OPEN FLAME. ALSO, USE ONLY IN A WELLVENTILATED AREA.
CONTROLS AND SWITCHES
The BTH-300 & 400 are equipped with four pressure switches.
These switches are essential to the safe and proper operation of
the unit. All switches are wired in series. The controller is set up
to shut the unit down whenever there is a failure of any of the
switches. It is important to understand the purpose of each switch.
FIGURE 13.
ON/OFF SWITCH
The ON/OFF Switch is a single-pole, single-throw rocker switch.
This switch provides 120V from the line source to the heater.
BLOWER PROVER SWITCH
The Blower Prover Switch is provided on the heater to verify that the
fan is operating. It is a positive pressure switch whose electrical
contacts are normally open. When the fan increases the pressure
in the burner, the pressure switch will allow the electrical contacts
CAUTION
THE WATER HEATER IS POLARITY SENSITIVE. BEFORE
APPLYING ELECTRICITY TO THIS HEATER BE CERTAIN THAT
SUPPLY NEUTRAL WIRE TO GROUND CHECK INDICATES ZERO
VOLTAGE.
13
FIRE OR EXPLOSION. IF OVERPRESSURE HAS OCCURRED
SUCH AS THROUGH IMPROPER TESTING OF GAS LINES OR
EMERGENCY MALFUNCTION OF THE SUPPLY SYSTEM THE
GAS VALVE MUST BE CHECKED FOR SAFE OPERATION. MAKE
SURE THAT THE OUTSIDE VENTS ON THE SUPPLY
REGULATORS AND THE SAFETY VENT VALVES ARE PROTECTED
AGAINST BLOCKAGE. THESE ARE PARTS OF THE GAS
SUPPLY SYSTEM, NOT THE HEATER. VENT BLOCKAGE MAY
OCCUR DURING ICE STORMS. IT IS IMPORTANT TO GUARD
AGAINST GAS VALVE FOULING FROM CONTAMINANTS IN
THE GAS WAYS. SUCH FOULING MAY CAUSE IMPROPER
OPERATION, FIRE OR EXPLOSION.
HOT SURFACE IGNITER
The Hot Surface Igniter is a device that ignites the main burner by
high temperature (>1800°F or >982°C). When 120VAC is applied
to the igniter, sufficient heat is generated to ignite the main burner.
Although improvements have been made to strengthen the igniter,
it is fragile and care must be taken when handling the igniter to
prevent breakage.
GAS PIPING
Contact your local gas service company to ensure that adequate
gas service is available and to review applicable installation codes
for your area.
IF COPPER SUPPLY LINES ARE USED THEY MUST BE
INTERNALLY TINNED AND CERTIFIED FOR GAS SERVICE.
BEFORE ATTACHING THE GAS LINE BE SURE THAT ALL GAS
PIPE IS CLEAN ON THE INSIDE.
Size the main gas line in accordance with Table 3. The figures
shown are for straight lengths of pipe at 0.5 in. W.C. (125Pa)
pressure drop, which is considered normal for low pressure
systems Note that fittings such as elbows and tees will add to the
pipe pressure drop.
TO TRAP ANY DIRT OR FOREIGN MATERIAL IN THE GAS
S U P P LY L I N E , A D I RT L E G ( S O M E T I M E S C A L L E D A
SEDIMENT TRAP OR DRIP LEG) MUST BE INCORPORATED
IN THE PIPING (SEE FIG. 14). THE DIRT LEG MUST BE
R E A D I LY A C C E S S I B L E A N D N O T S U B J E C T T O
FREEZING CONDITIONS. INSTALL IN ACCORDANCE WITH
RECOMMENDATIONS OF SERVING GAS SUPPLIERS.
REFER TO THE NATIONAL FUEL GAS CODE OR THE NATURAL
GAS AND PROPANE INSTALLATION CODE CSA B149.1.
CAUTION
DO NOT USE FLEXIBLE GAS PIPING.
TABLE 3. MAXIMUM CAPACITY OF PIPE IN CUBIC FEET OF GAS
PER HOUR (Based upon a Pressure Drop of 0.5 inch Water Column
and 0.6 Specific Gravity Gas and max. gas pressure of 0.5 psig).
LENGTH
IN
FEET
10
20
30
40
50
60
70
80
90
100
125
150
175
200
LENGTH
IN
METERS
3.0
6.1
9.1
12.2
15.2
18.3
21.3
24.4
27.4
30.5
38.1
45.7
53.3
61.0
1 1/4"
1400
950
770
660
580
530
490
460
430
400
360
325
300
1 1/4"
410
278
225
193
170
155
143
135
126
117
105
95
88
NORMAL IRON PIPE SIZES (INCHES)
INPUT IN THOUSANDS BTU/HR
1 1/2"
2"
2 1/2"
3"
2100
3960
6300
11000
1460
2750
4360
7700
1180
2200
3520
6250
990
1900
3000
5300
900
1680
2650
4750
810
1520
2400
4300
750
1400
2250
3900
690
1300
2050
3700
650
1220
1950
3450
620
1150
1850
3250
550
1020
1650
2950
500
950
1500
2650
460
850
1370
2450
430
800
1280
2280
NORMAL IRON PIPE SIZES (INCHES)
INPUT IN KW
1 1/2"
2"
2 1/2"
3"
615
1160
1845
3221
428
805
1277
2255
346
644
1031
1830
290
556
878
1552
264
492
776
1391
237
445
703
1259
220
410
659
1142
202
381
600
1083
190
357
571
1010
182
337
542
952
161
299
483
864
146
278
439
776
135
249
401
717
126
234
375
688
4"
23000
15800
12800
10900
9700
8800
8100
7500
7200
6700
6000
5500
5000
4600
FIGURE 14.
CONNECTION OF GAS PIPE
1. When connecting gas pipe to unit, apply wrench to flange only.
Note: Do not use wrench on gas valve or gas bracket.
2. PERFORM THE GAS LEAK TEST ANY TIME WORK IS DONE
ON A GAS SYSTEM TO AVOID THE POSSIBILITY OF FIRE OR
EXPLOSION WITH PROPERTY DAMAGE, PERSONAL INJURY
OR LOSS OF LIFE.
4"
6735
4626
3748
3192
2840
2577
2372
2196
2108
1962
1757
1610
1464
1347
The Gas Leak Test is performed as follows: Paint pipe connections
upstream of gas control with a rich soap and water solution to test
for leaks before operating main burner. Bubbles indicate gas leak.
To stop leak, tighten pipe connections. After piping connections
are checked, turn on main burner. With main burner in operation,
paint pipe joints (including flanges), pilot gas tubing connections
and control inlet and outlet with rich soap and water solution.
Bubbles indicate gas leak. To stop leak, tighten flange screws,
joints and pipe connections. Replace part if leak can’t be stopped.
To prevent damage, care must be taken not to apply too much
torque when attaching gas supply pipe to gas valve inlet.
Apply joint compounds (pipe dope) sparingly and only to the male
threads of pipe joints. Do not apply compound to the first two threads.
Use compounds resistant to the action of liquefied petroleum gases.
WARNING
THE HEATER IS NOT INTENDED FOR OPERATION AT HIGHER
THAN 11.0" WATER COLUMN (2.74 Kpa) FOR NATURAL GAS
AND 14.0" W.C. (3.49kPa) FOR PROPANE GAS SUPPLY
PRESSURE. HIGHER GAS SUPPLY PRESSURES REQUIRE
SUPPLEMENTAL REDUCING SERVICE REGULATION.
EXPOSURE TO HIGHER GAS SUPPLY PRESSURE MAY CAUSE
DAMAGE TO THE GAS CONTROLS WHICH COULD RESULT IN
DISCONNECT THE APPLIANCE AND ITS MANUAL GAS SHUTOFF
VALVE FROM THE GAS SUPPLY PIPING SYSTEM DURING ANY
SUPPLY PRESSURE TESTING EXCEEDING 1/2 PSIG (3.45Kpa).
GAS SUPPLY LINE MUST BE CAPPED WHEN DISCONNECTED
FROM THE HEATER. FOR TEST PRESSURES OF 1/2 PSIG (3.45Kpa)
14
OR LESS, THE APPLIANCE NEED NOT BE DISCONNECTED, BUT
MUST BE ISOLATED FROM THE SUPPLY PRESSURE TEST BY
CLOSING THE MANUAL GAS SHUTOFF VALVE.
FOR SAFE OPERATION OF THE WATER HEATER, THE RELIEF
VALVE(S) MUST NOT BE REMOVED OR PLUGGED.
BEFORE PLACING THE HEATER IN OPERATION, CHECK FOR
GAS LEAKAGE. USE SOAP AND WATER SOLUTION OR OTHER
MATERIAL ACCEPTABLE FOR THE PURPOSE OF LOCATING GAS
LEAKS. DO NOT USE MATCHES, CANDLES, FLAME OR OTHER
SOURCES OF IGNITION FOR THIS PURPOSE.
In addition to the appliance relief valve, each remote storage tank
which may be used in conjunction with this appliance shall also
be installed with a properly sized, rated and approved temperature
(ANSI) and pressure (ASME) relief valve(s). This relief valve shall
comply with the standard for relief valves and automatic gas shutoff
devices for hot water supply systems. ANSI Z21.22-CSA 4.4.
PURGING
Gas line purging is required with new piping or systems in which
air has entered.
CAUTION
PURGING SHOULD BE PERFORMED BY PERSONS
EXPERIENCED IN THIS TYPE OF GAS SERVICE. TO AVOID RISK
OF FIRE OR EXPLOSION, PURGE DISCHARGE MUST NOT ENTER
CONFINED AREAS OR SPACES WHERE IGNITION CAN OCCUR.
THE AREA MUST BE WELL VENTILATED AND ALL SOURCES OF
IGNITION MUST BE INACTIVATED OR REMOVED.
GAS METER SIZE - CITY GASES ONLY
Be sure that the gas meter has sufficient capacity to supply the
full rated gas input of the water heater as well as the requirements
of all other gas fired equipment supplied by the meter. If the gas
meter is too small, ask the gas company to install a larger meter
having adequate capacity.
Your local code authority may have other specific relief valve
requirements.
WARNING
THE PURPOSE OF A RELIEF VALVE IS TO AVOID EXCESSIVE
PRESSURE OR TEMPERATURE INTO THE STEAM RANGE,
WHICH MAY CAUSE SCALDING AT FIXTURES, TANK EXPLOSION,
SYSTEM OR HEATER DAMAGE. NO VALVE IS TO BE PLACED
BETWEEN THE RELIEF VALVE AND THE TANK.
A DRAIN LINE MUST BE CONNECTED TO THE RELIEF VALVE TO
DIRECT DISCHARGE TO A SAFE LOCATION TO AVOID SCALDING
OR WATER DAMAGE. THIS LINE MUST NOT BE REDUCED FROM
THE SIZE OF THE VALVE OUTLET AND MUST NOT CONTAIN
VALVES OR RESTRICTIONS, NOR SHOULD IT BE LOCATED IN
FREEZING AREAS. DO NOT THREAD OR CAP THE END OF THIS
LINE. RESTRICTED OR BLOCKED DISCHARGE WILL DEFEAT
THE PURPOSE OF THE VALVE AND IS UNSAFE. THE DISCHARGE
LINE SHALL BE INSTALLED TO ALLOW COMPLETE DRAINAGE
OF BOTH THE VALVE AND LINE.
GAS PRESSURE REGULATION
Main line gas pressure to the unit(s) should be a maximum
11.0" W.C. (2.74 Kpa) for natural gas and a maximum 14.0" W.C
(3.49 kPa) for propane gas. A minimum of 6.2" W.C. (1.54 Kpa) for
natural gas and a minimum of 11.0" W.C. (2.74 kPa) for propane gas.
The service regulator provided must be installed within 6' (183 cm)
of the unit and not closer than 3' of the unit. Install regulator
according to regulator manufacturer and local requirements.
GAS VALVES
WARNING
WATER LINE CONNECTIONS
This manual provides detailed installation diagrams (see back
section of this manual) for typical methods of application for the
water heaters.
The water heater may be installed by itself, or with a separate
storage tank. When used with a separate storage tank, the
circulation may be either by gravity or by means of circulating pump.
When a circulating pump is used, it is important to note that the
flow rate should be slow so that there will be a minimum of
turbulence inside the heater.
SHOULD OVERHEATING OCCUR OR THE GAS SUPPLY FAIL TO
SHUT OFF, TURN OFF THE MANUAL GAS CONTROL VALVE TO
THE APPLIANCE.
CLOSED SYSTEM
SYSTEM CONNECTIONS
A closed system will exist if a check valve (without bypass),
pressure reducing valve (without bypass), or a water meter (without
bypass) is installed in the cold water line between the water heater
and street main (or well).
CAUTION
The system installation must conform to these instructions and to
the local code authority having jurisdiction. Good practice requires
that all heavy piping be supported.
THERMOMETERS (Not Supplied)
Thermometers should be obtained and field installed as shown
in the installation diagrams.
Excessive pressure may develop causing premature tank failure
or intermittent relief valve operation. This type of failure is not
covered by the limited warranty. An expansion tank or a similar
device may be required in the inlet supply line between the
appliance and the meter or valve to compensate for the thermal
expansion of water under supply pressure.
Thermometers are installed in the system as a means of detecting
the temperature of the outlet water supply.
If a water heater is installed in a closed water system, check local
codes or contact the water supplier or local plumbing inspector on
how to control this situation.
RELIEF VALVE
WATER (POTABLE) HEATING AND SPACE HEATING
This heater is equipped with an approved temperature and
pressure relief valve. ASME ratings cover pressure relief. CSA
ratings cover release rate with temperature actuation.
1. All piping components connected to this unit for space
heating applications shall be suitable for use with potable
water.
15
2. Toxic chemicals, such as those used for boiler treatment,
shall NEVER be introduced into this system.
3. This unit may never be connected to any existing heating
system or component(s) previously used with non-potable
water heating appliance.
4. When the system requires water for space heating at
temperatures higher than required for domestic water
purposes, a tempering valve must be installed. Please refer
to installation diagrams on pages 23 through 28 in back of
manual for suggested piping arrangements.
EMF OF RFI INTERFERENCE CAN CAUSE THE CONTROLLER
TO MALFUNCTION. A HIGH QUALITY POWER CONDITIONER
MUST BE INSTALLED IF THE ABOVE CONDITIONS EXIST.
MALFUNCTIONS CAUSED BY A POOR ELECTRICAL SUPPLY
ARE NOT COVERED UNDER YOUR WARRANTY.
The controller is wired to the heater as shown in figures 15 &
16. The model and rating plate provides the electrical
information needed to size the complete heater branch supply.
All electrical work must be installed in accordance with the
National Electrical Code, NFPA 70 or the Canadian Electrical
Code, CSA C22.1 and local requirements.
HEATER WIRING
IF ANY OF THE ORIGINAL WIRE AS SUPPLIED WITH THE
APPLIANCE MUST BE REPLACED, IT MUST BE REPLACED
WITH 105°C OR ITS EQUIVALENT, EXCEPT IN THE BURNER
HOUSING. IN THIS CASE USE 200°C WIRE.
THE COMPUTER CONTROL REQUIRES A SOURCE OF
STABLE CLEAN ELECTRICITY FOR PROPER OPERATION.
INSTALLING THE HEATER ON A BRANCH CIRCUIT THAT HAS
ELECTRONIC NOISE, IS SUBJECT TO FLUCTUATIONS IN
VOLTAGE LEVEL OR HAS AN APPLIANCE WHICH GENERATES
When installed, the appliance must be electrically grounded in
accordance with local codes or, in the absence of local codes,
with the National Electrical Code, ANSI/NFPA 70 or the Canadian
Electrical Code, CSA C22.1.
DO NOT ENERGIZE THE BRANCH CIRCUIT BEFORE THE
HEATER TANK IS FILLED WITH WATER.
NOTE: This controller is Polarity Sensitive. If the Hot and
Neutral Supply Voltage is reversed, the controller will not sense
flame. Verify polarity before connecting the unit.
WHC1202 INTEGRATED WATER HEATER CONTROL
CONNECTION DIAGRAM
FIGURE 15.
16
be closed, and the blower will continue to run for approximately
10 seconds. The control will then return to step 2.
9.
If a flame is confirmed, the control will enter the heating mode
where it will continue heating the tank water until the setpoint
temperature plus differential is reached. At this point, the gas
valve is closed and the control enters the post-purge cycle.
10. The combustion blower will run for the duration of the post
purge cycle to purge the system of all combustion gases.
When the post purge cycle is complete, the blower is
de-energized and will coast to a stop.
11. The control will now enter the idle state while continuing to
monitor the internal tank water temperature and the state of
other system devices. If the temperature drops below the
setpoint value less differential, the control will automatically
return to step 2 and repeat the entire operating cycle. During
this idle state, if the control detects an improper operating state
for external devices such as the ECO switch, vent switch,
pressure switch, etc., the appropriate LED(s) on the Display
Board will be illuminated indicating the nature of the fault.
SELF DIAGNOSTIC CONTROLLER
This controller is designed for ignition lockout after three consecutive
failed attempts to light. If lockout occurs, the display lights will
match Figure 17. Along with this, a numeric message will appear
in the display. The following list of ERROR CODES illustrates
possible numeric failures.
FIGURE 16.
OPERATION
SEQUENCE OF OPERATION
Typical Control/Appliance Operating Sequence
1.
When the control is powered, it should first display “0”, then
the input line voltage (“120”), the calibration setting (12), then
the actual water temperature in the tank.
2.
If the control determines that the actual water temperature
inside the tank is below the programmed temperature setpoint
less the differential, a call for heat is activated.
3.
The control then performs selected system diagnostic checks.
This includes confirming the proper state of the air switches
and ECO limit device.
4.
If all checks are successfully passed, the combustion blower
is energized for the pre-purge cycle.
5.
When the pre-purge cycle is complete, power is applied to the
ignitor element for the ignitor warm-up period.
FIGURE 17.
GAS VALVE LED FLASHING
This condition results from a failure to establish burner ignition
after three successive trials. In such cases:
1. Investigate the possible cause and remedy any observations.
2. Momentarily depress the button on the display panel to reset
the lockout condition.
3. Confirm proper appliance operation.
Possible Cause
1.
6.
At the conclusion of the igniter warm-up period, the gas valve
will open, allowing gas to enter the burner chamber.
7.
The igniter will remain on for a short predetermined time
period, then will be turned off.
8.
After an additional 2 seconds, the control will monitor the flame
sense probe to confirm a flame is present. If a flame is not
verified within this time period, the gas valve will immediately
2.
3.
4.
5.
6.
7.
8.
9.
10.
17
Burner ground wire broken
or corroded
Connectors unplugged
Igniter broken
Flame probe faulty
Gas shut off
Clogged gas valve
Faulty gas valve
Defective control
Burner improperly adjusted
Dirty burner
Remedy
1. Check wire and connection
at burner
2. Check connections
3. Replace igniter
4. Replace flame probe
5. Turn on gas supply
6. Replace gas valve
7. Replace gas valve
8. Replace control
9. Adjust burner
10. Clean burner
ERROR CODES
Possible Cause
The following Error Codes are external to the controller.
01 Pressure Switch Fail On, should be Off
11 Pressure Switch Fail Off, should be On
02 Ignition Fail after 3 attempts
04 ECO Open
05 Temperature Probe Open
15 Temperature Out of Bounds < 30 degrees
25 Temperature Out of Bounds > 220 degrees
The following Error Codes are internal to the controller.
113 Flame On Should be Off Fail
22 Ignition Relay Fail is On, should be Off
112 Ignition Relay Fail is Off, should be On
101 K2 Fail in K1
102 Main Loop Fail in K2
103 K1 Fail in Main Loop
Remedy
1. No Input Power
1. Apply Power
2. Wiring Disconnected
2. Check all wiring
3. One or more wiring receptacles
disconnected from control
3. Reconnect plugs on control,
confirm all are fully seated
4. LED burned out
4. Ignore or replace control
NO LOW VOLTAGE. See Figure 19.
24V AC LED Off
Gas Valve Power Supply. (*WDPS Watch Dog Power Supply).
106 WDPS Fail to be Off
107 WDPS Fail to be Off
108 WDPS Fail to be On
116 Gas Valve Relay Fail is off, should be On
117 Gas Valve Relay Fail is On, should be Off
Checks The ROM (Read Only Memory).
200 CRC Check Sum Error
Checks The CPU (Central Processing Unit).
201 CPU Instruction Test Error
202 CPU Instruction Test Error
203 CPU Instruction Test Error
Checks the RAM (Random Access Memory).
205 RAM Test Fail
NO LOW VOLTAGE, 24V AC LED Off
FIGURE 19.
SW Check to see what the Last State it was in.
ie., Fails if it can from the wrong place
125 State Error
126 State Error
128 State Error
127 State Error
129 State Error
131 State Error
132 State Error
NOTE: The transformer is of Class II variety and has an internal nonreplaceable fuse. If blown, a problem may exist with the control which is
affecting the transformer. In such cases, the control should be replaced as
well.
Possible Cause
These State Numbers are not used.
230 Executed State 3 (Not Implemented) h.s.
240 Executed State 4 (Not Implemented) h.s
210 Executed State 10 (Not Implemented) h.s.
213 Executed State 13 (Not Implemented) h.s.
214 Executed State 14 (Not Implemented) h.s.
216 Executed State 16 (Not Implemented) h.s.
Remedy
1. Transformer wiring problem
1. Repair Wiring
2. Defective Transformer
2. Replace Transformer
3. LED burned out
3. Ignore or replace control
TEMPERATURE PROBE FAULT. See Figure 20.
Water Temp LED Flashing
FAULT CONDITIONS
The controller is set up to provide additional status indicators under Fault
Conditions. The following figures are possible Fault Conditions.
NO INCOMING LINE VOLTAGE. See Figure 18.
Line LED Off
TEMPERATURE PROBE FAULT, Water Temp LED Flashing
FIGURE 20.
NO INCOMING LINE VOLTAGE, Line LED Off
This condition accommodates multiple failure modes. To more accurately
determine the cause of failure, press the push-button on the display board.
FIGURE 18.
18
Display Flashes “05” when button is pressed:
Possible Cause
Remedy
1. Temperature Probe wiring
open
1. Repair Wiring
2. Defective probe
2. Replace probe
Display Flashes “15” when button is pressed:
Possible Cause
Remedy
1. No water in tank and tank
in freezing conditions
1. The symptom does not
reflect a control problem
2. Water in tank above freezing
2. Temperature probe out of
tolerance, replace temp.
probe
CONTROL BAD, All LEDs Flashing
FIGURE 22.
Possible Cause
Display Flashes “25” when button is pressed:
Possible Cause
Remedy
1. Water in tank is low, probe
immersed in steam
1. Fill tank
2. Probe wiring shorted
2. Repair wiring
3. Defective probe
3. Replace probe
Remedy
1. Temp. Probe unplugged
1. Check connectors
2. Temp. probe wiring damaged
2. Repair wiring
3. Water in tank too hot
3. Normal condition when
water t e m p e r a t u r e
exceeds safety limit.
Allow water to cool or
admit water into tank and
manually reset the control.
Determine cause for
overtemp condition.
COMBUSTION AIR BLOCKAGE. See Figure 23.
Pressure Switch LED Flashing:
ECO SWITCH OPEN. See Figure 21.
ECO LED Flashing:
COMBUSTION AIR BLOCKAGE, Pressure Switch LED Flashing
FIGURE 23.
ECO SWITCH OPEN, ECO LED Flashing
Possible Cause
FIGURE 21.
Possible Cause
1. This indicates the control has
failed on of its internal
diagnostic self-tests.
Remedy
1. Press button on the
display board to reset
control. If this error
occurs repeatedly,
replace control.
CONTROL BAD. See Figure 22.
All LEDs Flashing:
19
Remedy
1. Combustion air blocked
1. Check exhaust piping and
flue for obstructions
2. Blower not operating:
a. Check blower wiring
b. Check blower motor
2. a. Repair wiring
b. Replace blower motor
3. Defective air switch
3. Replace air switch
4. Pressure switch jumped out
4. This controller must sense
an open contact on the
blower proving airflow
switch before the blower
comes on. Check to see if
blower proving airflow
switch is still connected to
the unit.
DO NOT USE THIS HEATER IF ANY PART HAS BEEN UNDER
WATER. IMMEDIATELY CALL A QUALIFIED SERVICE
TECHNICIAN TO INSPECT THE HEATER AND TO REPLACE ANY
PART OF THE CONTROL SYSTEM AND ANY GAS CONTROL
WHICH HAS BEEN UNDER WATER.
PRIOR TO START UP - REQUIRED ABILITY
INSTALLATION OR SERVICE OF THIS WATER HEATER REQUIRES
ABILITY EQUIVALENT TO THAT OF A LICENSED TRADESMAN IN
THE FIELD INVOLVED. PLUMBING, AIR SUPPLY, VENTING, GAS
SUPPLY AND ELECTRICAL WORK ARE REQUIRED.
LIGHT THE UNIT IN ACCORDANCE WITH THE OPERATING
INSTRUCTIONS LABEL ATTACHED TO THE HEATER.
Before attempting start-up, thoroughly study and familiarize yourself
with the exact sequence of operation and all other details on the
specific heater being used.
THESE INSTRUCTIONS ARE REPEATED IN THE LIGHTING AND
OPERATING LABEL ILLUSTRATION ON PAGE 20 IN THIS
MANUAL.
The power burner is equipped with an ignition system which
automatically sequences prepurge and ignition, senses and ignites
main burner flame and sequences burner operation. Heater is
equipped with an ignition control which locks out after three
unsuccessful ignition attempts. Familiarize yourself with the
sequence of operation of this unit prior to start-up.
ADJUSTMENT PROCEDURE - INITIAL START-UP
A minimum dynamic gas supply pressure of 6.2" W.C. (1.54 kPa)
for Natural Gas and 11" W.C. (2.74 kPa) for LP Gas is required
before making any adjustment to the gas control pressure regulator
Attempts to adjust the regulator during periods of low gas supply
pressure could result in overfiring of the heater when the gas supply
pressure returns to normal.
Be certain that the water heater is full of water, that air is purged
from all lines, there are no leaks (gas and water), and all inlet
water lines are open.
The following test equipment should be on hand (all test equipment
must be acclimated to ambient temperature before calibration and
use.)
1. Check gas line pressure with a manometer.
2. Check manifold pressure (see Table 4, page 20) using a pressure
gauge (manometer) connected to the manifold pressure tap on
the gas control valve, (Figure 15).
– Two U-tube manometers or calibration 0-10" W.C. (0-2.5Kpa)
and 0-35" W.C. (0-8.7Kpa) pressure gauges.
• Attach a gas pressure gauge or manometer to the upstream
side of main gas cock and a gas pressure gauge or manometer
to the manifold pressure tap.
• You are now ready to begin the burner start-up procedure.
If full rate adjustment is required, remove cover screw from top of
the gas control valve, (Figure 15).
Using a small screwdriver, turn adjusting screw clockwise
to
increase or counterclockwise
to decrease gas pressure to obtain
5.0" W.C. (1.25 kPa) for Natural Gas and 10" W.C. (2.49 kPa) for
LP gas.
OPERATING INSTRUCTIONS
IMPORTANT
IT IS RECOMMENDED THAT A QUALIFIED SERVICE
TECHNICIAN PERFORM THE INITIAL FIRING OF THE HEATER.
AT THIS TIME THE USER SHOULD ASK THE TECHNICIAN ANY
QUESTIONS IN REGARD TO THE OPERATION AND
MAINTENANCE OF THE UNIT.
3. Cycle the burner on and off several times to check its operation.
4. Check the operation of the limit and operating controls.
5. Check the vent system seams and joints and ensure that there
is no discharge of flue products into the room.
6. Check the input rate:
CAUTION
For appliance installation locations with elevations above 2000 feet
(610 m) refer to HIGH ALTITUDE INSTALLATIONS section of this
manual.
BEFORE PROCEEDING WITH THE OPERATION OF THE UNIT,
MAKE SURE HEATER AND SYSTEM ARE FILLED WITH WATER
AND ALL AIR IS EXPELLED FROM HEATER AND PIPING.
a. Attach a pressure gauge (manometer) to the manifold
pressure tap (Figure 16) and refer to Table 4, page 20 for
correct pressure.
NEVER OPERATE THE HEATER WITHOUT FIRST BEING
CERTAIN IT IS FILLED WITH WATER AND A TEMPERATURE
AND A PRESSURE RELIEF VALVE IS INSTALLED IN THE RELIEF
VALVE OPENING OF THE HEATER. DO NOT ATTEMPT TO
OPERATE HEATER WITH COLD WATER INLET VALVE CLOSED.
b. Use this formula to “clock” the meter. Be sure other gas
consuming appliances are not operating during this interval.
FILLING:
1. Close the heater drain valve.
2. Open a nearby hot water faucet to permit the air in the system
to escape.
3. Fully open the cold water inlet pipe valve allowing the heater
and piping to be filled.
4. Close the hot water faucet as water starts to flow.
5. The heater is ready to be operated.
3600 X H = Btuh
T
3600
X 1050 = 300,000 Btuh (87.9 kW)
12.6
T = Time in seconds to burn 1 cubic foot of gas. (With a stopwatch
read the gas meter and measure the amount of time required
for the heater to consume 1 cubic foot of gas.)
H = Heating value of gas (in Btu’s per cubic foot of gas).
Btuh = Actual heater input rate, in Btuh.
EXAMPLE: (Using BTH-300 heater)
T = 12.6 seconds
H = 1050 Btu/ft.3
BTUH = ?
THE MAIN MANUAL GAS SHUTOFF VALVE MUST HAVE BEEN
CLOSED FOR AT LEAST FIVE (5) MINUTES. THIS WAITING
PERIOD IS AN IMPORTANT SAFETY STEP. ITS PURPOSE IS
TO PERMIT GAS THAT MIGHT HAVE ACCUMULATED IN THE
COMBUSTION CHAMBER TO CLEAR. IF YOU DETECT GAS AT
THE END OF THIS PERIOD, DO NOT PROCEED WITH
LIGHTING. RECOGNIZE THAT GAS ODOR, EVEN IF IT SEEMS
WEAK, MAY INDICATE THE PRESENCE OF ACCUMULATED
GAS SOMEPLACE IN THE AREA WITH A RISK OF FIRE OR
EXPLOSION. SEE THE FRONT PAGE FOR STEPS TO BE TAKEN.
For high altitude installations, compare result to the derated input
required for the elevation at the installation location.
Should it be necessary to adjust the gas pressure to the burner,
to obtain the full input rate, the steps below should be followed:
20
e. Repeat steps (c) and (d) until the specified input rate is
achieved.
c. Remove the pressure regulator cover screw (Figure 16) and
adjust the pressure by turning the adjusting screw with a small
screwdriver. In this example, with heater running on natural
gas, do not exceed 5.0" (1.25 kPa) Water Column.
f. Turn the manual gas valve to “OFF”. Replace the pressure
regulator cover screw. Remove the pressure gauge or
manometer from the manifold pressure tap. Replace the
set screw in the manifold pressure tap. If the gas pressure
regulator cannot be adjusted to give the full input rating
with sufficient gas pressure at the valve, check to ensure
the unit is equipped with the correct orifice.
Clockwise to increase gas pressure and input rate.
Counterclockwise to decrease gas pressure and input rate.
d. “Clock” the meter as in step (b) above.
LIGHTING AND OPERATION INSTRUCTIONS
FOR YOUR SAFETY READ BEFORE OPERATING
WARNING
A.
B.
IF YOU DO NOT FOLLOW THESE INSTRUCTIONS EXACTLY A FIRE OR EXPLOSION
MAY RESULT CAUSING PROPERTY DAMAGE, PERSONAL INJURY OR LOSS OF LIFE.
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.
•
•
C.
Use only your hand to push in or turn the gas control knob.
Never use tools. If the knob will not push in or turn by
hand, don’t try to repair it, call a qualified service technician.
Force or attempted repair may result in fire or explosion.
D.
Do not use this appliance if any part has been under water.
Immediately call a qualified service technician to inspect
the appliance and to replace any part of the control system
and any gas control which has been under water.
BEFORE OPERATING smell all around the appliance area
for gas. Be sure to smell next to the floor because some
gas is heavier than air and will settle on the floor.
“WHAT TO DO IF YOU SMELL GAS”
•
•
department.
Do not try to light any appliance.
Do not touch any electric switch; do not use any telephone
in your building.
Immediately call your gas supplier from a neighbor’s
telephone. Follow the gas supplier’s instructions.
If you cannot reach your gas supplier, call the fire
OPERATING INSTRUCTIONS
1.
STOP! Read the safety information above on this
label.
2.
Set thermostat to lowest setting.
3.
Turn off all electric power to the appliance.
4.
This appliance is equipped with an ignition device which
automatically lights the burner. Do not try to light the burner
by hand.
5.
9.
Set thermostat to desired setting.
10.
If the appliance will not operate, follow the instructions “To
Turn Off Gas To Appliance” and call your service technician
or gas supplier.
Push in gas control knob slightly and turn clockwise
to “OFF”.
6.
Wait five (5) minutes to clear out any gas.
If you then
smell gas,
STOP! Follow “B” in the safety information
above on
this label. If you don’t smell gas, go on to the
next step.
7.
Turn gas control knob counterclockwise
8.
Turn on all electric power to the appliance.
to “ON”.
FOR YOUR SAFETY READ BEFORE OPERATING
1.
Set the thermostat to lowest setting.
2.
Turn off all electric power to appliance if service is to be performed.
3.
Push in gas control knob slightly and turn clockwise
to “OFF”. Do not force.
21
WARNING
HIGH ALTITUDE INSTALLATIONS
UNDER NO CIRCUMSTANCES SHOULD THE INPUT EXCEED
THE RATE SHOWN ON THE HEATER RATING PLATE.
OVERFIRING COULD RESULT IN DAMAGE OR SOOTING OF THE
HEATER.
WARNING
BTH HEATERS ARE CERTIFIED FOR USE WITHOUT
MODIFICATION FOR ALTITUDES UP TO 2000 FEET.
INSTALLATIONS ABOVE 2000 FEET MAY REQUIRE
REPLACEMENT OF THE BURNER ORIFICE. CALL THE
TECHNICAL INFORMATION CENTER AT (800) 527-1953 FOR
REQUIREMENTS.
CATHODIC PROTECTION
CAUTION
HYDROGEN GAS CAN BE PRODUCED IN A HOT WATER SYSTEM
SERVED BY THIS HEATER THAT HAS NOT BEEN USED FOR A
LONG PERIOD OF TIME (GENERALLY TWO WEEKS OR MORE).
HYDROGEN GAS IS EXTREMELY FLAMMABLE. To reduce the risk
of injury under these conditions, it is recommended that a hot
water faucet be opened for several minutes before using any
electrical appliance connected to the hot water system. If hydrogen
is present, there will probably be an unusual sound such as air
escaping through the pipe as the water begins to flow. There should
be no smoking or open flame near the faucet at the time it is open.
HIGH ALTITUDE ADJUSTMENTS
FOR BTH 300 AND 400
NATURAL GAS
ELEVATION (ft./m)
MANIFOLD SETTING (in W.C./Kpa)
Up to 2,000 ft./610 m.
PRECAUTIONS
IF THE UNIT IS EXPOSED TO OR EXHIBITS THE FOLLOWING,
DO NOT OPERATE HEATER UNTIL ALL CORRECTIVE STEPS
HAVE BEEN MADE BY A QUALIFIED SERVICEMAN.
1. FLOODING TO OR ABOVE THE LEVEL OF THE BURNER OR
CONTROLS
2. EXTERNAL DAMAGE
3. FIRING WITHOUT WATER
4. SOOTING
5.0/1.25 - NO ADJUSTMENT
2,001 - 3,000 ft./914 m.
4.8/1.19
3,001 - 4,000 ft./1,219 m.
4.7/1.17
4,001 - 5,000 ft./1,524 m.
4.6/1.14
5,001 - 6,000 ft./1,829 m.
4.5/1.12
6,001 - 7,000 ft./2,134 m.
4.5/1.12
7,001 - 8,000 ft./2,438 m.
4.4/1.09
PROPANE GAS
NEVER OPERATE THE HEATER WITHOUT FIRST BEING CERTAIN
IT IS FILLED WITH WATER AND A TEMPERATURE AND
PRESSURE RELIEF VALVE IS INSTALLED IN THE RELIEF VALVE
OPENING OF THE HEATER.
ELEVATION (ft./m)
MANIFOLD SETTING (in W.C./Kpa)
Up to 2,000 ft./610 m.
SHOULD OVERHEATING OCCUR OR THE GAS SUPPLY FAIL TO
SHUT OFF, TURN OFF THE MANUAL GAS CONTROL VALVE TO
THE APPLIANCE.
GENERAL INFORMATION
POWER BURNER
10.0/2.49 - NO ADJUSTMENT
2,001 - 3,000 ft./914 m.
9.9/2.46
3,001 - 4,000 ft./1,219 m.
9.8/2.44
4,001 - 5,000 ft./1,524 m.
9.7/2.41
5,001 - 6,000 ft./1,829 m.
8.4/2.09
6,001 - 7,000 ft./2,134 m.
7.2/1.79
7,001 - 8,000 ft./2,438 m.
6.1/1.52
The sequence of operation of the unit is provided on page 16.
Some gas utility companies derate their gas for altitude, making
it unnecessary to install high altitude orifices. Call the local gas
or utility company to verify BTU content.
It is important to note that the controller has a reset button on the
control box, Figure 1. The reset button is a safety device and would
not normally be used.
Due to the input rating reduction at high altitudes, the output rating
of the appliance is also reduced and should be compensated for
in the sizing of the equipment for applications.
The initial start-up procedure of the unit is provided on page 19.
HIGH LIMIT
The high limit (not adjustable) is factory set to cutout at
202°F (94°C). The controller must be manually reset by depressing
the reset button on front of the control when water temperature
drops to below 160°F (71°C).
TABLE 4.
GAS SUPPLY SPECIFICATIONS
Max. Gas Supply Pressure W.C.
Max. Gas Supply Pressure kPa
Nominal Gas Supply Pressure W.C.
Nominal Gas Supply Pressure kPa
Minimum Gas Supply Pressure W.C.*
Minimum Gas Supply Pressure kPa*
Manifold Gas Supply Pressure W.C.
Manifold Gas Supply Pressure kPa
MAINTENANCE
GENERAL
KEEP APPLIANCE AREA CLEAR AND FREE FROM
COMBUSTIBLE MATERIALS, GASOLINE AND OTHER FLAMMABLE
VAPORS AND LIQUIDS. (SEE WARNING ON PAGE 5, LOCATING
THE HEATER).
Nat. Gas LP Gas
11.00
2.74
7.00
1.74
6.20
1.54
5.00
1.25
14.00
3.49
11.00
2.74
11.0
2.74
10.0
2.49
Water heater maintenance includes periodic tank flushing and
cleaning, and removal of lime scale. The unit should be
inspected and adjusted to maintain proper combustion. Refer
to the following table. A periodic inspection of the venting system
should be made. Where used, the water circulating pump
should be oiled.
* Minimum pressure for purposes of rate adjustment
22
MAINTENANCE SCHEDULE
SEDIMENT REMOVAL
Following are the instructions for performing some of the
recommended maintenance. Unit inspection and adjustment
should be performed by a competent technician.
Waterborne impurities consist of the particles of soil and sand
which settle out and form a layer of sediment on the bottom of
the tank.
For convenience, sediment removal and lime scale removal
should be performed at the same time.
COMPONENT
OPERATION
INTERVAL
REQUIRED
Tank
Sediment
Monthly
Flushing
Removal
Tank
Powered Anode
Lime Scale
Semi
UN-LIME®
Removal
Annually
Delimer
Inspect
System
Relief Valve
Semi
Semi
Annually
SAE No. 20
Circulating
Oiling
Four Months
The amount of calcium carbonate (lime) released from water is
in direct proportion to water temperature and usage. The higher
the water temperature or water usage, the more lime deposits
are dropped out of the water. This is the lime scale which forms in
pipes, heaters and on cooking utensils.
Lime accumulation not only reduces the life of the equipment but
also reduces efficiency of the heater and increases fuel
consumption.
Annually
Inspect
LIME SCALE REMOVAL
non-detergent
Pump (1)
motor oil
Clean Inlet
Blower
Screen and
Blower Wheel
As Required
Soft Brush
Vent System
Inspect
Every 3
Joints should
Months
be sealed
The usage of water softening equipment greatly reduces the
hardness of the water. However, this equipment does not
always remove all of the hardness (lime). For this reason it is
recommended that a regular schedule for deliming be
maintained.
The depth of lime buildup should be measured periodically.
Heaters will have about 3" (7.6cm) of lime buildup when the level
of lime has reached the bottom of the cleanout opening or about
1" (2.5cm) of lime buildup if it has reached the drain valve opening.
A schedule for deliming should be set up, based on the amount
of time it would take for a 1" (2.5cm) buildup of lime.
Example 1:
Initial inspection shows 1/2" (1.3cm) of lime accumulation.
Therefore, the heater can be delimed once a year.
(1) If furnished with oiling provision.
NOTE: UN•LIME is not available in Canada. Please call Customer
Service at 1-800-265-8520 for approved alternatives.
FLUSHING
1. Turn off the heater electrical disconnect switch.
2. Open the drain valve and allow water to flow until it runs clean.
Example 2 :
Initial inspection shows 2" (5cm) of lime accumulation.
Therefore, the heater should be delimed every 3 months.
Sediment and lime scale removal may be accomplished through
the cleanout opening furnished on the heater, see Figure 24. The
heater must be drained, see DRAINING, before removing cleanout
cover on tank.
3. Close the drain valve when finished flushing.
4. Turn on the heater electrical disconnect switch.
DRAINING
The heater must be drained if it is to be shut down and exposed
to freezing temperatures. Maintenance and service procedures
may also require draining the heater.
1. Turn off the heater electrical disconnect switch.
2. Close the cold water inlet valve to heater.
3. Open a nearby hot water faucet to vent the system.
4. Open the heater drain valve.
5. If the heater is being drained for an extended shutdown, it is
suggested the drain valve be left open during this period.
• Follow FILLING instructions when restoring hot water service.
FIGURE 24.
23
To dissolve and remove the more stubborn mineral deposits,
A.O. Smith UN•LIME® Professional Delimer should be used.
NOTE: UN•LIME is not available in Canada. Please call Customer
Service at 1-800-265-8520 for approved alternatives.
A.O. Smith UN•LIME® Professional Delimer is an easy to handle
patented food grade acid formulated specifically for lime scale
removal from all types of water using equipment. Available in
1 gallon (3.8L) (part no. 4763) and 5 gallon (19L) (part no. 4813)
sizes. Hydrochloric base acids are not recommended for use on
glass-lined tanks.
A.O. Smith Form No. 4800 Rev. 8, entitled “Why, When and How”,
describes tank cleaning methods and materials. UN•LIME and
the booklet may be obtained through your A.O. Smith dealer or
distributor.
The cleanout opening is shown in Figure 24. To clean heater
through cleanout opening, proceed as follow:
1. Turn off water inlet valve, the heater electrical disconnect switch
and open drain valve.
2. Remove outer cover plate from lower side of heater jacket.
3. Remove cover from cleanout opening.
4. Remove lime, scale or sediment using care not to damage
the glass-lining.
5. Inspect cleanout plate gasket: If new gasket is required, replace
with A. O. Smith part no. 99038.
FIGURE 25.
POWER SUPPLY LED MEANINGS:
6. Install cleanout plate. Be sure to draw plate up tight by
tightening screws securely.
The power supply diagnostic LED is located in the bottom righthand corner of the BTH-300 & 400 control board.
7. Close drain valve, open water inlet line and turn on the power
burner electrical disconnect switch.
Steady green light means powered anode system is functioning normally.
8. Check for water leakage.
No light means no line voltage or a defective power supply.
9. Replace outer jacket cover plate.
Flashing red light can mean (1) the heater has no water or
(2) a broken or loose connection has occurred.
POWERED ANODE SYSTEM
DRAIN VALVE AND ACCESS PANELS
The BTH-300 & 400 are factory equipped with a powered anode
system. The anodes are of a permanent design and do not need
replacing unless damaged.
The heaters are equipped with a 3/4" drain valve.
An access panel covers the cleanout opening in the tank which is
sealed by a gasket and cover, see Figure 24.
POWERED ANODE OPERATION
RELIEF VALVE
To insure a long, trouble-free operating life, the BTH-300 & 400
are equipped with a powered anode system consisting of:
At least twice a year, the temperature and pressure relief valve
should be checked to ensure that it is in operating condition. To
check the relief valve, lift the lever at the end of the valve several
times. The valve should seat properly and operate freely.
1.
A power supply with a built-in diagnostic LED.
2.
Two titanium anodes.
3.
Wiring harness with ground lead.
Replacement parts for this system may be ordered from A.O.
Smith Product Service Division; see BTH-300 & 400 parts list for
specific details.
24
If water does not flow, remove and inspect for obstructions or
corrosion. Replace with a new valve of the recommended size as
necessary. Inspection of the valve should be performed at least
every three years. Do not attempt to repair the valve, as this could
result in improper operation and a tank explosion. In areas with
poor water conditions, it may be necessary to inspect the
T&P valve more often than every three years.
INTERNAL CIRCULATING PUMP
CAUTION
BEFORE MANUALLY OPERATING THE VALVE, MAKE SURE THAT
A DRAIN LINE HAS BEEN ATTACHED TO THE VALVE TO DIRECT
THE DISCHARGE TO AN OPEN DRAIN. FAILURE TO TAKE THIS
PRECAUTION COULD MEAN CONTACT WITH EXTREMELY HOT
WATER PASSING OUT THE VALVE DURING THIS CHECKING
OPERATION.
The BTH-300 & 400 are factory equipped with an internal
circulating pump. This pump is maintenance free with no oil
needed for periodic lubricating.
If the temperature and pressure relief valve on the heater
discharges periodically or continuously, it may be due to thermal
expansion of water in a closed water supply system, or, it may be
due to a faulty relief valve.
CIRCULATING PUMP - FIGURE 26
Thermal expansion is the normal response of water when it is
heated. In a closed system, thermal expansion will cause the
system pressure to build until the relief valve actuation pressure is
equaled. Then, the relief valve will open, allowing some water to
escape, slightly lowering the pressure.
Examine the vent system every 3 months. Points of inspection
are as follows:
Contact your water supplier or local plumbing inspector on how to
control this situation.
1. Check for obstructions and/or deterioration of vent piping and
vent hood. Replace immediately where needed.
Two common corrections are listed in the Checklist and Service
Information which appears later in this manual.
ABOVE ALL, DO NOT PLUG THE TEMPERATURE AND PRESSURE
RELIEF VALVE. THIS IS NOT A SOLUTION AND CAN CREATE A
HAZARDOUS SITUATION.
VENT SYSTEM
2. Vent pipe and vent hood screen should be cleaned of foreign
material and soot. The screen is located inside the vent hood
outlet and is accessible from the outside of the hood. Do not
reach inside the vent hood when the heater is in operation.
3. Check all vent system connections for leakage and reseal as
required using Hi Temp Silicone sealer or equivalent.
25
INSTALLATION DIAGRAMS
ONE TEMPERATURE - ONE HEATER VERTICAL STORAGE TANK FORCED CIRCULATION
WITH OR WITHOUT BUILDING RECIRCULATION
CAUTION: IF BUILDING COLD
WATER SUPPLY HAS A BACKFLOW PREVENTER, CHECK
VALVE OR WATER METER
WITH
CHECK
VALVE
PROVISIONS FOR THERMAL
EXPANSION OF WATER IN THE
HOT WATER SYSTEM MUST
BE PROVIDED
NOTE: CONNECT RETURN
LINE FROM HOT WATER
CIRCULATING LOOP (IF USED)
TO COLD WATER INLET LINE.
* PIPE TO OPEN DRAIN
INSTALL IN ACCORDANCE
WITH LOCAL CODES
ONE TEMPERATURE - ONE HEATER HORIZONTAL STORAGE TANK
FORCED CIRCULATION WITH OR WITHOUT BUILDING RECIRCULATION
DANGER
TEMPERATURE SETTING SHOULD NOT EXCEED
SAFE TEMPERATURE AT FIXTURES. SEE WATER
TEMPERATURE CONTROL WARNING ON PAGE 3.
IF HIGHER PREHEAT TEMPERATURES ARE
NECESSARY TO OBTAIN ADEQUATE BOOSTER
OUTPUT, ADD AN ANTI-SCALD VALVE FOR HOT
WATER SUPPLIED TO FIXTURES.
*PIPE TO OPEN DRAIN
INSTALL IN ACCORDANCE
WITH LOCAL CODES
26
TWO TEMPERATURE - ONE HEATER HIGH TEMPERATURE
WITH OR WITHOUT BUILDING RECIRCULATION
DANGER
TEMPERATURE SETTING SHOULD NOT EXCEED SAFE
TEMPERATURE AT FIXTURES. SEE WATER
TEMPERATURE CONTROL WARNING ON PAGE 3. IF
HIGHER PREHEAT TEMPERATURES ARE NECESSARY
TO OBTAIN ADEQUATE BOOSTER OUTPUT, ADD AN
ANTI-SCALD VALVE FOR HOT WATER SUPPLIED TO
FIXTURES.
*PIPE RELIEF VALVE TO OPEN DRAIN.
NOTE:
IF TEMPERED WATER IS
RECIRCULATED, RETURN LINE SHOULD BE
CONNECTED AT POINT “A”.
INSTALL IN ACCORDANCE WITH LOCAL
CODES.
CAUTION: IF BUILDING COLD WATER SUPPLY HAS A
BACK-FLOW PREVENTER, CHECK VALVE OR WATER
METER WITH CHECK VALVE PROVISIONS FOR
THERMAL EXPANSION OF WATER IN THE HOT WATER
SYSTEM MUST BE PROVIDED.
27
TWO TEMPERATURE - TWO HEATERS HIGH TEMPERATURE
WITH OR WITHOUT BUILDING RECIRCULATION
TWO TEMPERATURE - THREE HEATERS (TWO PRE-HEATERS/ONE BOOSTER HEATER)
WITH OR WITHOUT BUILDING RECIRCULATION
MUST BE IDENTICAL HEATERS
FOR MULTIPLE HEATER INSTALLATION SEE MANIFOLD KIT
SPECIFICATIONS, PAGE 30.
CAUTION: IF BUILDING COLD WATER SUPPLY HAS A BACKFLOW PREVENTER, CHECK VALVE OR WATER METER WITH
CHECK VALVE PROVISIONS FOR THERMAL EXPANSION OF
WATER IN THE HOT WATER SYSTEM MUST BE PROVIDED.
28
DANGER
TEMPERATURE SETTING SHOULD NOT EXCEED SAFE
TEMPERATURE AT FIXTURES. SEE WATER TEMPERATURE
CONTROL WARNING ON PAGE 3. IF HIGHER PREHEAT
TEMPERATURES ARE NECESSARY TO OBTAIN ADEQUATE
BOOSTER OUTPUT, ADD AN ANTI-SCALD VALVE FOR HOT
WATER SUPPLIED TO FIXTURES.
TWO TEMPERATURE - TWO HEATERS (ONE PRE-HEATER/ONE BOOSTER HEATER)
WITH OR WITHOUT BUILDING RECIRCULATION
DANGER
* PIPE RELIEF VALVE TO OPEN DRAIN
TEMPERATURE SETTING SHOULD NOT EXCEED SAFE TEMPERATURE
AT FIXTURES. SEE WATER TEMPERATURE CONTROL WARNING ON
PAGE 3. IF HIGHER PREHEAT TEMPERATURES ARE NECESSARY TO
OBTAIN ADEQUATE BOOSTER OUTPUT, ADD AN ANTI-SCALD VALVE
FOR HOT WATER SUPPLIED TO FIXTURES
** 140°F (60°C)TO 150°F (66°C) SHOULD BE MAXIMUM WATER
TEMPERATURE MAINTAINED IN THE PRE-HEATERS.
120°F (49°C) SHOULD BE THE MINIMUM TEMPERATURE OF
WATER IN THE PRE-HEATERS.
CONNECT CIRCULATING LINE FROM FIXTURES, IF USED,
TO COLD WATER SUPPLY LINE OF PRE-HEATER.
CONNECT CIRCULATING LINE OF 180°F (82°C) OR
BOOSTED WATER, IF USED, TO INLET WATER LINE TO
BOOSTER.
INSTALL IN ACCORDANCE WITH LOCAL CODES.
29
TWO TEMPERATURE - ONE HEATER HIGH TEMPERATURE
WITH RECIRCULATION OF SANITIZING LOOP
DANGER
TEMPERATURE SETTING SHOULD NOT EXCEED SAFE
TEMPERATURE AT FIXTURES. SEE WATER TEMPERATURE
CONTROL WARNING ON PAGE 3. IF HIGHER PREHEAT
TEMPERATURES ARE NECESSARY TO OBTAIN ADEQUATE
BOOSTER OUTPUT, ADD AN ANTI-SCALD VALVE FOR HOT
WATER SUPPLIED TO FIXTURES.
CAUTION: IF BUILDING COLD WATER SUPPLY HAS A BACKFLOW PREVENTER, CHECK VALVE OR WATER METER WITH
CHECK VALVE PROVISIONS FOR THERMAL EXPANSION OF
WATER IN THE HOT WATER SYSTEM MUST BE PROVIDED.
*PIPE RELIEF VALVE TO OPEN DRAIN
NOTE 1: TOGGLE SWITCH CONTROLS 180°F (82°C) WATER
CIRCULATION. INSTALL ON OR CLOSE TO DISHWASHER.
TOGGLE SWITCH MUST BE CLOSED (ON) DURING THE RINSE
OPERATION AND OPEN (OFF) WHEN DISHWASHER IS NOT
OPERATING OR WHEN ON LONG STANDBY.
NOTE 2: INSTALL LINE TEMPERATURE CONTROL IN AN
UNINSULATED TEE BEYOND THE DISHWASHER TAKEOFF IN
THE SANITIZING LOOP. CONTROL SHOULD BE SET AT
185°F (85°C).
NOTE 3: ADJUST PLUG COCK SO THE SANITIZING LOOP
FLOW RATE DOES NOT CAUSE UNNECESSARY TURBULENCE
IN THE TANK.
NOTE 4: IF TEMPERED WATER IS RECIRCULATED, RETURN
LINE SHOULD BE CONNECTED AT POINT A.
INSTALL IN ACCORDANCE WITH LOCAL CODES
30
MANIFOLD KITS
Precision cut type “L” all copper A.O. Smith manifold kits assure water flow balance of all units. Without this balance, the full water
heating and storage potential of the system cannot be achieved. Plus, the units with the higher water flow may have a shortened life.
Unions shown in piping diagrams are not included in the manifold kits.
Dimensions shown are for minimum space occupied by the water heaters assemblies.
Space for the venting system and unit servicing must be added.
31
2. Some of the electrical components of the water heater make
sounds which are normal.
• Contacts click or snap as the heater starts and stops.
• Transformers often hum.
CHECKLIST AND SERVICE INFORMATION
IMPORTANT
The installer may be able to observe and correct certain problems
which might arise when the unit is put into operation or when it is
re-fired after a prolonged shutdown. HOWEVER, it is recommended
that only qualified servicemen, using appropriate test equipment,
be allowed to service the heater.
WATER LEAKAGE IS SUSPECTED
1. Check to see if the water heater drain valve is tightly closed.
Also check the cleanout opening for leakage.
2. The apparent leakage may be condensation which forms on
cool surfaces of the heater and piping.
3. If the outlet of the relief valve is leaking it may represent:
• Excessive water pressure.
• Excessive water temperature.
• Faulty relief valve.
BE SURE TO TURN OFF THE ELECTRICITY WHENEVER
POSSIBLE OR APPROPRIATE WHILE CHECKING EQUIPMENT.
WARNING
FAILURE TO FOLLOW THESE INSTRUCTIONS CAN RESULT
IN SERIOUS PERSONAL INJURY OR DEATH.
Excessive water pressure is the most common cause of relief valve
leakage. It is often caused by a “closed system”. If a check valve is
in the inlet system it will not permit the expanded hot water volume
to equalize pressure with the main. The relief valve must release
this water or the water heater or plumbing system will be damaged.
Refer to MAINTENANCE-RELIEF VALVE section in this manual.
CAUTION:
LABEL ALL WIRES PRIOR TO DISCONNECTION WHEN
SERVICING CONTROLS. WIRING ERRORS CAN CAUSE
IMPROPER AND DANGEROUS OPERATION.
VERIFY PROPER OPERATION AFTER SERVICING.
When such a condition is encountered, local codes or inspection
agency should be consulted to determine which system is
acceptable in your area. See CLOSED SYSTEM section in this manual.
BURNER OPERATIONAL PROBLEMS
1. Refer to TROUBLESHOOTING.
TROUBLE-SHOOTING
NOT ENOUGH OR NO HOT WATER
1.
1. Be certain the electrical disconnect switch serving the water
heater is in the ON position.
2. Check the fuses.
• The electrical disconnect switch usually contains fuses.
2.
3. The capacity of the heater may have been exceeded by a large
demand for hot water.
• Large demands require a recovery period to restore water
temperature.
3.
4.
Verify that the allowable vent length has not been exceeded
and that the blower inlet screen has been removed if direct
venting.
Verify that the condensation, which WILL be present in the
heater and exhaust vent, will drain.
Check supply wire polarity - hot to hot and neutral to neutral
and no "stray" current in neutral.
Heater is properly grounded.
Checking these four (4) items first will often result in a timely solution
to the service call.
4. Colder incoming water temperature will lengthen the time
required to heat water to the desired temperature.
• If the heater was installed when incoming water temperature
was warm, colder water creates the effect of less hot water.
WARNING
JUMPING OUT COMPONENTS AND/OR CIRCUITS DURING
TROUBLESHOOTING CAN CAUSE SERIOUS PROBLEMS WITH
THE UNIT’S OPERATING SEQUENCE AND IGNITION SAFETY.
IF YOU DO NOT HAVE THE PROPER TEST EQUIPMENT, I.E. A
VOLT-OHM METER AND A MICROMETER, DO NOT ATTEMPT
TO TROUBLESHOOT OR REPAIR A.O. SMITH EQUIPMENT.
5. Look for hot water wastage and leaking or open hot water
faucets.
6. Sediment or lime scale may be affecting water heater operation.
Refer to MAINTENANCE for details.
ALTERING THE CONTROLLER AND/OR CONTROLLER WIRING
IN ANY WAY COULD RESULT IN INTERNAL DAMAGE TO THE
MODULE CIRCUITS, POSSIBLY ALTERING THE IGNITION
SEQUENCE ALLOWING GAS VALVES TO OPEN BEFORE THE
HOT SURFACE IGNITER IS UP TO IGNITION TEMPERATURE.
7. The heater’s temperature high limit sensor has activated. Press
the reset button on the thermostat.
8. Burner may not be firing at proper rate.
• Check gas pressure. Adjust to obtain required manifold
pressure.
NOTE: ANY BYPASS OR ALTERATION OF THE UNITS
SAFETIES WILL RESULT IN VOIDING THE APPLIANCE
WARRANTY.
9. Burner fan wheel may be dirty.
• Clean fan wheel with a stiff brush.
Before performing any troubleshooting familiarize yourself with the
particular appliance.
10. Condensate hose may be blocked where it connects to the
exhaust elbow.
• Verify the condensate drains from the unit without restriction.
Refer to the SEQUENCE OF OPERATION and the connection
diagram located on page 16 before continuing.
WATER IS TOO HOT
Make sure the appliance is connected to a 120V AC power supply,
manual gas valve is in the ON position, and all electrical connections
are secure before continuing to troubleshoot this appliance.
1. Refer to WATER TEMPERATURE CONTROL.
WATER HEATER MAKES SOUNDS
CAUTION
1. Sediment or lime scale accumulations cause rumbling and
pounding noises when the heater is operating.
THE WATER HEATER IS POLARITY SENSITIVE. BEFORE
APPLYING ELECTRICITY TO THIS HEATER BE CERTAIN THAT
SUPPLY NEUTRAL WIRE TO GROUND CHECK INDICATES
ZERO VOLTAGE.
• The sounds are normal, however, the tank bottom should
be cleaned. Refer to MAINTENANCE for details.
32
MOTOR WILL NOT RUN
in Table 4: that is, for Natural Gas, 6.2" (1.54 kPa) W.C. pressure.
Also, the manifold pressure should rise during the three (3)
second trial for ignition to the manifold pressure value for the
individual unit listed in Table 4: that is, for Natural Gas,
5.0" (1.25 kPa) W.C. If the manifold pressure is not correct then
adjust accordingly. See ADJUSTMENT PROCEDURE in
OPERATING INSTRUCTIONS section, page 19, for the manifold
pressure adjustment procedure.
1. Confirm 120V AC to the controller. Also, to verify correct polarity,
check for 120 V AC between hot supply and ground.
If there is no voltage, check for a loose connection where it
connects to the controller.
2. If there is 120 volts to the controller, check for loose connections
or a locked rotor. If the rotor cannot be freed the motor and
blower assembly must be replaced.
MOTOR RUNS, PREPURGE TIME ELAPSES BUT
MAIN FLAME NOT ESTABLISHED.
1. Check to see if main manual gas valve is open.
2. Check for a loose connection at the transformer, or a defective
transformer.
3. Check for a loose connection at the gas valve.
4. Check for open pressure switches or open reset button. Check
for blockage in the intake and exhaust venting or at the vent
hoods. If no blockage is found, check vinyl tubing for cuts or
crimps. If this tubing is damaged it must be replaced. If these
steps do not eliminate the problem, replace the pressure
switches.
5. Check to see if there is resistance across the igniter terminal
with an OHM meter. If there is no continuity, the igniter is broken
and should be replaced.
If the igniter appears to function properly, then verify that the
inlet pressure is 11.0" Natural Gas (2.74 kPa). The gas valve
supplied on this appliance is not designed to open against a
higher pressure. At this time also check that the inlet pressure
is not lower than the minimal gas supply pressure, as shown in
Table 4: that is, for Natural Gas, 6.2" (1.5 kPa) W.C. If the inlet
pressure is not within these limits then adjust the supply pressure
accordingly.
If the inlet pressure falls within the allowable limits, then verify
that the manifold pressure, when the gas is fully open, with the
heater running, is as called out in Table 4: that is, for Natural
Gas, 5.0" (1.25 kPa) W.C. If the manifold pressure is not correct
then adjust accordingly. See ADJUSTMENT PROCEDURE in
OPERATING INSTRUCTIONS selection, page 19, for the
manifold pressure adjustment procedure.
6. If the inlet and manifold pressures are within the limits specified
in step 5, then reset the appliance. Verify 24V AC at the gas
valve during the three (3) second ignition trial, after the igniter
reaches operating temperature. If 24V AC at the gas valve is
not seen during this period, the controller must be replaced.
If there is 24V AC at the gas valve during the four second ignition
trial and the manifold pressure does not increase above 0" W.C.
then verify that the manual gas control valve is in the “ON”
position (see page 20). If the valve is in the “ON” position and
the previous voltage and gas pressure conditions are met, then
the gas valve is defective and must be replaced.
Note that a positive manifold pressure reading of approximately
1.5" (.38 kPa) W.C. is normal during the prepurge portion of the
ignition cycle due to the location of the gas orifice.
3. Check for the reversed polarity in the supply wiring. This controller
is polarity sensitive. If the hot and neutral supply wires are
reversed, the controller will not sense flame. Reverse the supply
wires and try to fire the unit.
NOTE: Always turn off and disconnect main supply wiring before
servicing the unit.
4. Check connecting wire to the flame sensor. Verify that the flame
sensor has not been damaged in any way.
5. Verify that the air supply is adequate. The air inlet screen or
blower wheel may be restricted. Also, check the installation for
proper ventilation. See AIR REQUIREMENTS.
6. Check the venting system for the correct sizing, excess or
insufficient. See VENTING.
7. Check for a maximum inlet pressure of 11" Natural Gas
(2.74 kPa) W.C. and the manifold pressure as listed in Table 4:
that is, for Natural Gas, 5.0" (1.25 kPa) W.C. Please note that
the manifold pressure listed is the maximum value for the
manifold pressure. Do not set the manifold pressure higher than
the value shown for your heater in Table 4. Overfiring the heater
will result in rough ignition and/or noisy operation.
8. Confirm that the air inlet screen (see Figures 7 & 8) is free of
obstructions.
CAUTION
Do not reach into the burner housing or combustion chamber if the
heater is still hot. Allow the heater to cool and always use gloves
as the combustion chamber and the burner sleeve and housing
can become very hot after operation. Overfiring is a dangerous
condition that must be corrected immediately.
NOISY BURNER OPERATION
The exhaust of this unit produces some noise. This noise may be
objectionable if the exhaust terminal is located too close to the
opening of an occupied space. The noise may also be objectionable
if the exhaust is located in the confined space between two buildings
such as an alley or walkway. Since everyone's perception and
tolerance for background noise varies, there is no standard
recommendation. The best option when the noise is a concern is
to locate the exhaust as far away from any occupied spaces as
practical.
If noise becomes more than one can tolerate, a dampening muffler
is available through our Product Service Division. See
“REPLACEMENT PARTS” segment below.
GAS FAILS TO SHUT OFF
Check for defective gas valve or thermostat. If operation is incorrect,
replace.
REPLACEMENT PARTS
MOTOR RUNS, BURNER LIGHTS MOMENTARILY,
THEN LOCKS OUT
1. Reset the appliance two more times to ensure that all of the air
has been purged from the gas line.
2. If the burner lights momentarily but does not sustain ignition,
verify that the inlet pressure is not greater than 11.0" (2.74 kPa)
W.C. or lower than the minimal gas supply pressure, as shown
Replacement parts may be ordered through A.O. Smith dealers,
authorized servicers or distributors. Refer to the Yellow Pages for
where to call or contact the A.O. Smith Water Products Company,
125 Southeast Parkway, Franklin, TN 37068, 1-800-433-2545.
When ordering parts be sure to state the quantity, part number and
description of the items including the complete model and serial
number as it appears on the product. Refer to the parts list for
more information.
33
Model BTH Limited Warranty
A. O. Smith Corporation, the warrantor, extends the following LIMITED WARRANTY to the owner of this water heater.
1.
2.
3.
4.
5.
6.
7.
THE TANK
If the glass-lined tank in this water heater shall prove upon examination by the warrantor to have leaked due to natural corrosion from potable water
therein, during the first THREE years after initial installation, the warrantor will supply a replacement tank less burner and controls or a complete new
A.O. Smith water heater of equivalent size and current model at the warrantor's option. Some government agencies are requiring energy efficient
standards for water heaters. In the event regulations prohibit sale of a model of equivalent size and construction, A.O. Smith will provide a model
which complies with the regulations of your area, in which case the consumer will be charged the difference in price between the like replacement
and the energy efficient model required. The warranty on the replacement water heater will be limited to the unexpired term of the original warranty.
ALL OTHER PARTS
If within ONE year after initial installation of this water heater, any part or portion shall prove upon examination by the warrantor to be defective in
material or workmanship, the warrantor will repair or replace such part or portion at its option.
CONDITIONS AND EXCEPTIONS
This warranty shall apply only when the water heater is installed in accordance with local plumbing and building codes, ordinances and regulations,
the printed instructions provided with it and good industry practices. In addition, a temperature and pressure relief valve, certified by A.G.A. and
approved by the American Society of Mechanical Engineers, must have been installed.
a. This warranty shall apply only when the heater is:
(1) owned by the original purchaser;
(2) used at temperatures not exceeding the maximum setting of its thermostat;
(3) used at water pressure not exceeding the working pressure shown on the heater;
(4) used when operated free of the damaging effects of uncontrolled water hammer;
(5) used when filled with potable water, free to circulate at all times;
(6) used in a non-corrosive and non-contaminated atmosphere;
(7) used with factory approved anode(s) installed;
(8) in its original installation location;
(9) in the United States, its territories or possessions, and Canada;
(10) sized in accordance with proper sizing techniques for commercial water heaters;
(11) bearing a rating plate which has not been altered, defaced or removed except as required by the warrantor;
(12) fired at the factory rated input using the fuel stated on the rating plate;
(13) maintained in accordance with the instructions printed in the manual included with the heater.
b. Any accident to the boiler, any misuse, abuse (including freezing) or alteration of it, any operation of it in a modified form, or any attempt to repair
tank leaks will void this warranty.
c. This warranty is void if a device acting as a backflow prevention device (check valves etc.) is installed in the cold water supply the heater is
connected to, unless an effective method of controlling thermal expansion is also installed at the heater(s) and operational at all times.
The relief valve installed on the heater is not an acceptable method.
SERVICE AND REPAIR EXPENSES
Under the limited warranty the warrantor will provide only a replacement water heater or part thereof. The owner is responsible for all other costs.
Such costs may include but are not limited to:
a. Labor charges for service removal, repair or reinstallation of the water heater or any component part;
b. Shipping, delivery, handling, and administrative charges for forwarding the new heater or replacement part from the nearest distributor and
returning the claimed defective heater or part to such distributor.
c. All cost necessary or incidental for any material and/or permits required for installation of the replacement.
LIMITATIONS ON IMPLIED WARRANTIES
Implied warranties, including the warranty of merchantability imposed on the sale of this heater under state law are limited to one (1) year duration
for the heater or any of its parts. Some states do not allow limitations on how long an implied warranty lasts, so the above limitation may not apply
to you.
CLAIM PROCEDURE
Any claim under the warranty should be initiated with the dealer who sold the water heater, or with any other dealer handling the warrantor’s
products. If this is not practicable, the owner should contact:
U.S. Customers
Canadian Customers
A. O. Smith Corporation
A. O. Smith Enterprises Ltd.
500 Tennessee Waltz Parkway
P. O. Box, 310 - 768 Erie Street
Ashland City, TN 37015
Stratford (Ontario) N5A 6T3
Telephone: 1-(800)-323-2636
Telephone: 1-(800) 265-8520
a. The warrantor will only honor replacement with identical or similar water heater or parts thereof which are manufactured or distributed by the
warrantor.
b. Dealer replacements are made subject to in-warranty validation by warrantor.
DISCLAIMERS
NO OTHER EXPRESS WARRANTY HAS BEEN OR WILL BE MADE IN BEHALF OF THE WARRANTOR WITH RESPECT TO THE
MERCHANTABILITY OF THE HEATER OR THE INSTALLATION, OPERATION, REPAIR OR REPLACEMENT OF THE WATER HEATER. THE WARRANTOR
SHALL NOT BE RESPONSIBLE FOR WATER DAMAGE, LOSS OF USE OF THE UNIT, INCONVENIENCE, LOSS OR DAMAGE TO PERSONAL
PROPERTY OR OTHER CONSEQUENTIAL DAMAGE. THE WARRANTOR SHALL NOT BE LIABLE BY VIRTUE OF THIS WARRANTY OR
OTHERWISE FOR DAMAGE TO ANY PERSONS OR PROPERTY, WHETHER DIRECT OR INDIRECT, AND WHETHER ARISING IN CONTRACT
OR TORT.
a. Some states do not allow the exclusion or limitation of the incidental or consequential damage, so the above limitations or exclusions may not
apply to you.
b. This warranty gives you specific legal rights, and you may also have other rights which vary from state to state.
Fill in the following for your own reference. Keep it. Registration is not a condition of warranty. The model and serial number are found on the heater’s rating plate.
Date Installed________________________Model No.____________________________________________ Serial No._________________________________________________
Dealer’s Name _____________________________________________________________________Phone No.______________________________________________________
Dealer’s Address__________________________________________________City and State________________________________________Zip Code____________________
FILL IN WARRANTY AND KEEP FOR FUTURE REFERENCE.
34
NOTES
35
A DIVISION OF A.O. SMITH CORPORATION
Mc BEE, SOUTH CAROLINA
STRATFORD (ONTARIO) CANADA
w w w.hotwater.com
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