A.O. Smith CYCLONE Xi BTH 400A Manual

1
A DIVISION OF A.O. SMITH CORPORATION
Mc BEE, SOUTH CAROLINA
STRATFORD (ONTARIO) CANADA
www.hotwater.com
PLACE THESE INSTRUCTIONS ADJACENT TO HEATER AND NOTIFY OWNER TO KEEP FOR FUTURE REFERENCE.
PRINTED IN U.S.A. 0903 PART NO. 195792-000
SUPERSEDES PART NO. 195049-000
CYCLONE XHE® Model BTH 300A AND 400A
COMMERCIAL GAS WATER HEATER
GAS-FIRED POWER BURNER
FOR DOMESTIC HOT WATER
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 THOROUGHLYBEFORE INSTALLING AND USING
THIS APPLIANCE.
• 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.
– Installation and service must be
performed by a qualified installer,
service agency or the gas supplier.

2
These designs comply with the latest version 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.
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.
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.
In the absence of local codes, the installation must comply with the
latest editions of the National Fuel Gas Code, ANSI Z223.1/NFPA
54 and the National Electric Code, NFPA 70 CSA B149.1 and
CSA C22.1. The former is available from the Canadian Standards
Association, 8501 East Pleasant Valley Road, Cleveland, OH 44131,
and both documents are available from the National Fire Protection
Association, 1 Batterymarch Park, Quincy, MA 02269.
FOREWORD
ROUGH-IN-DIMENSIONS
GAS VALVE PIPING
BTH-300 3/4" NPT
BTH-400 3/4" NPT
Recovery capacities are based on heater performance at 98% thermal efficiency.
U.S. Gallons/Hr and Litres/Hr at TEMPERATURE RISE INDICATED
TYPE OF INPUT Approx. F° 20F° 30F° 40F° 50F° 60F° 70F° 80F° 90F° 100F° 110° 120F° 130F° 140F°
MODEL GAS BTUH KW Capacity C° 11C° 17C° 22C° 28C° 33C° 39C° 44C° 50C° 56C° 61C° 67C° 72C° 78C°
300,000 130 US Gals. GPH 1782 1188 891 713 594 509 445 396 356 324 297 274 255
88 492 Litres LPH 6745 4496 3372 2698 2248 1927 1686 1499 1349 1226 1124 1038 964
280,000 130 US Gals. GPH 1663 1109 832 665 554 475 416 370 333 302 277 256 238
82 492 Litres LPH 6295 4197 3148 2518 2098 1799 1574 1399 1259 1145 1049 968 899
400,000 130 US Gals. GPH 2376 1584 1188 950 792 679 594 528 475 432 396 366 339
117 492 Litres LPH 8993 5995 4496 3597 2998 2569 2248 1998 1799 1635 1499 1384 1285
400,000 130 US Gals. GPH 2376 1584 1188 950 792 679 594 528 475 432 396 366 339
117 492 Litres LPH 8993 5995 4496 3597 2998 2569 2248 1998 1799 1635 1499 1384 1285
TABLE 1, RECOVERY CAPACITIES
NATURAL
NATURAL
PROPANE
BTH-300
BTH-300
BTH-400
BTH-400 PROPANE

DANGER
THIS WATER HEATER IS EQUIPPED WITH AN ADJUSTABLE
THERMOSTAT TO CONTROL WATER TEMPERATURE. HOT
WATER TEMPERATURES REQUIRED FOR AUTOMATIC
DISHWASHER ANDLAUNDRYUSECAN CAUSESCALD BURNS
RESULTING IN SERIOUS PERSONAL INJURY AND/OR DEATH.
THETEMPERATURE ATWHICH INJURYOCCURS 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.
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.
IMPORTANT
IT IS REQUIRED THAT A QUALIFIED SERVICE TECHNICIAN
PERFORMTHE INITIALFIRING OF THE HEATER. ATTHIS 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.
ACHECKLIST AND SERVICEINFORMATION section areincluded
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
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
FaultConditions............................................................................... 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
PRIORTOSTART-UP ........................................................................... 18
RequiredAbility ............................................................................... 18
OPERATING INSTRUCTIONS ................................................................ 18
Adjustment Procedure (Initial Start-Up) .......................................... 18
Lighting Instructions ........................................................................ 19
Cathodic Protection ......................................................................... 20
Precautions ..................................................................................... 20
GENERALINFORMATION .................................................................... 20
Power Burner ................................................................................. 20
HighLimit ......................................................................................... 20
HighAltitudeInstallations ................................................................ 20
MAINTENANCE .................................................................................... 20
General............................................................................................ 20
Maintenance Schedule ................................................................... 20
Flushing ........................................................................................... 21
Draining ........................................................................................... 21
SedimentRemoval........................................................................... 21
LimeScaleRemoval ........................................................................ 21
Powered Anode System.................................................................21-22
Drain Valve and Access Panels ..................................................... 22
Relief Valve ..................................................................................... 22
InternalCirculatingPump ................................................................. 22
Vent System .................................................................................... 22
INSTALLATIONDIAGRAMS .................................................................23-27
Manifold Kits .................................................................................... 28
CHECKLISTANDSERVICEINFORMATION .......................................... 29
TROUBLE-SHOOTING..........................................................................29-30
REPLACEMENTPARTS ........................................................................ 30
LIMITEDWARRANTY ........................................................................... 31
PAGE
ROUGH-INDIMENSIONS ................................................................... 2
FOREWORD ...................................................................................... 2
FEATURES ........................................................................................ 3
Water Temperature Control.......................................................... 3-4
High Limit Switch (E.C.O.)............................................................ 4
Dishwashing Machine Requirement ............................................ 4
CirculatingPump........................................................................... 4
INSTALLATIONINSTRUCTIONS ........................................................ 4
RequiredAbility ............................................................................ 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 PipeTermination ................................................................... 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
CONTROLSANDSWITCHES ............................................................ 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
GASPIPING....................................................................................... 12
Connection of Gas Pipe ............................................................... 12-13
Purging ......................................................................................... 13
Gas Meter Size - City Gases Only .............................................. 13
Gas Pressure Regulation............................................................. 13
Gas Valves................................................................................... 13
SYSTEMCONNECTIONS .................................................................. 13
Thermometers .............................................................................. 13
Relief Valve .................................................................................. 13
Water Line Connections .............................................................. 13
TABLE OF CONTENTS
FEATURES

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.
SETTING THE WATER HEATER TEMPERATURE AT 120°F/49°C
WILL REDUCE THE RISK OF SCALDS. Some states require
settings at specific lower temperatures.
Figure1 shows the approximate time-to-burnrelationship fornormal
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 Time toProduce2nd& 3rd
Setting DegreeBurnson Adult Skin
180°F/82°C Nearlyinstantaneous
170°F/77°C Nearlyinstantaneous
160°F/71°C About 1/2 second
150°F/66°C About 1-1/2 seconds
140°F/60°C Lessthan 5 seconds
130°F/54°C About30 seconds
120°F/49°C Morethan 5minutes
FIGURE 1
Valves for reducing point-of-use temperature by mixing cold and
hotwaterare available (seeFigure2). Also availableareinexpensive
devices that attach to faucets to limit hot water temperatures.
Contact a licensed plumber or the local plumbing authority.
FIGURE 2
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.
Continuedmanual 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.
• 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.
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.
The National Sanitation Foundation also recommends circulation
of 180°F (82°C) water. Where this is done, the circulation should
bevery gentleso that it does not cause any unnecessary turbulence
inside the water heater. The circulation should be just enough to
provide180°F(82°C) water atthepoint of take-offtothedishwashing
machine. Adjust flow by means of the plug cock in the circulating
line. (See installation diagrams.)
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 latest version of the
National Electric Code ANSI/NFPA No. 70 or Canadian Code CSA
C22.1.
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.
INSTALLATION INSTRUCTIONS
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 SUPPLYAND ELECTRICAL WORKARE
REQUIRED.
INSULATION BLANKETS
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
90.1b 1992 standards with respect to insulation and standby loss
requirements, making an insulation blanket unnecessary.

5
WARNING
THISWATER HEATER IS ACONDENSING UNITAND 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 BUILD-
UP WILL BLOCK THE EXHAUST OUTLET, WHICH WILL CAUSE
IMPROPER OPERATION.
FIGURE 3
WARNING
DONOT USE THISAPPLIANCE IFANY PARTHAS 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.
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.
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).
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.
Always disconnect electrical power before servicing the unit
*ILLUSTRATION OF MINIMUM COMBUSTIBLE CLEARANCES IN AN ALCOVE.
FIGURE 4
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
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.
•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
THEREISA RISK INUSING FUEL BURNINGAPPLIANCES 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.
THE HEATER SHALL BE LOCATED OR PROTECTED SO IT IS
NOTSUBJECT TO PHYSICAL DAMAGEBY A MOVINGVEHICLE.
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.
WARNING
FLAMMABLE ITEMS, PRESSURIZED CONTAINERS OR ANY
OTHER POTENTIAL FIRE HAZARDOUS ARTICLES MUST
NEVERBE 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.
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.
THE HEATER MUST NOT BE LOCATED IN AN AREA WHERE IT
WILL BE SUBJECT TO FREEZING.
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
ADJACENTAREAORTOLOWERFLOORSOFTHESTRUCTURE.
When such locations cannot be avoided, it is recommended that a
suitable drain pan, adequately drained, be installed under the
appliance.

6
See MAINTENANCE section for details of tank cleanout procedure.
AIR REQUIREMENTS
KEEP APPLIANCE AREA CLEAR AND FREE OF COMBUSTIBLE
MATERIALS, GASOLINE AND OTHER FLAMMABLE VAPORS
AND LIQUIDS.
DO NOT OBSTRUCT THE FLOW OF COMBUSTION AND
VENTILATING AIR.
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
INAYELLOW,LUMINOUSBURNERFLAME,CAUSINGCARBONING
OR SOOTING OF THE COMBUSTION CHAMBER, BURNERS AND
FLUE TUBES AND CREATES A RISK OF ASPHYXIATION.
MECHANICAL EXHAUSTING OF ROOM AIR
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
INTOTHEROOMTHROUGHTHE HEATER’SVENTING SYSTEM,
CAUSING POOR COMBUSTION. SOOTING MAY RESULT IN
SERIOUS DAMAGE TO THE HEATER AND RISK OF FIRE OR
EXPLOSION.IT CANALSO CREATE A RISK OF ASPHYXIATION.
UNCONFINED SPACE
In buildings of conventional frame, brick or stone construction,
unconfined spaces may provide adequate air for combustion and
ventilation.
If the unconfined space is within a building of tight construction
(buildingsusing thefollowing construction:weather stripping,heavy
insulation, caulking, vapor barrier, etc.), air for combustion and
ventilation must be obtained from outdoors. The installation
instructionsfor confined spaces in tightlyconstructed buildingsmust
be followed to ensure adequate air supply.
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).
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.
CHEMICAL VAPOR CORROSION
WARNING
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.
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.
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. IFNECESSARY,UNCONTAMINATEDAIR SHOULD
BE OBTAINED FROM REMOTE OR OUTSIDE SOURCES.
VENTING
WARNING
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.
Heatermust be protectedfrom freezing downdraftsduring shutdown
periods.
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.
VENT PIPE TERMINATION
NOTE: Before installing venting, determine place of vent pipe
termination. See Figure 5 and 6 before proceeding.
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
maintainedas cited inlocal codesor the latestedition ofthe National
Fuel Gas Code, ANSI Z223.1/NFPA 54 and for Canadian
installations consult the Canadian Installation Codes and
CAN/CGA B149.1 and .2.
1. Do notterminatethe exhaust ventterminalover public areawhere
condensate or vapor can cause nuisance or hazard.
2. For direct vent, the venting system shall terminate at least
1' (30.5 cm) below, 1' (30.5 cm) horizontally from or 1' (30.5
cm) above any door, window, or gravity air inlet into building.
3. For thehorizontal venting system,using room airfor combustion,
the vent terminal shall terminate 4' (122 cm) below, 4' (122 cm)
horizontally from or 1' (30.5 cm) above any door, window, or
gravity air inlet into building.

7
BTH 300 & 400
FIGURE 5
DIRECT VENT
HORIZONTAL VENT
FIGURE 6
DO NOT TERMINATE EXHAUST
OVER PUBLIC AREA WHERE
CONDENSATE OR VAPOR CAN
CAUSE NUISANCE OR HAZARD.
ON DIRECT VENT INSTALLATIONS, INLET VENT
HOOD MUST BE LOCATED 1' (30.5cm) MINIMUM
FROM ANY OPENING IN BUILDING.
ONDIRECTVENT INSTALLATIONS,EXHAUST VENT
HOOD MUST BE LOCATED 4' (122cm) MINIMUM
FROM ANY OPENING IN BUILDING.

8
4. The manufacturer also recommends the vent system
terminations not be installed closer than 3' (91cm) from an inside
corner of an L shaped structure. And not less than 1' (30.5 cm)
above grade or anticipated snow level.
5. The vent termination shall not be mounted directly above or
within 3' (91cm) horizontally from an oil tank vent or gas meter
to avoid potential freeze-up from condensation.
6. The vent shall terminate a minimum of 12" (30.5 cm) above
expected snowfall level to prevent blockage of vent termination.
Plan the vent system layout so that proper clearances are
maintained from plumbing and wiring.
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
Plan the layout of the vent system backwards from the vent
termination to the appliance.
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.
DIRECT VENTING
The air intake provided on the unit contains a mesh screen (see
Figure 7).
3" (7.6cm) 45° PVC ELBOW WITH MESH SCREEN
FIGURE 7
WARNING
WHEN THE UNIT IS TO BE SETUP AS A DIRECT VENT, THE
MESH SCREEN MUST BE REMOVED. THE INLET VENT PIPE
MAY THEN BE GLUED TO THE AIR INTAKE (see Figure 8)
PROVIDED ON THE UNIT.
FIGURE 8
DIRECT VENT TERMINAL INSTALLATION
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.
NOTE: TO PREVENT EXHAUSTING PRODUCTS FROM
CIRCULATING TO THE AIR INTAKE IN WINDY/COLD AREAS,
THEMAXIMUM PRACTICAL DISTANCE BETWEEN THESE TWO
TERMINALS IS RECOMMENDED.
IMPORTANT
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.
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).
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
PIPEREADTHE VENT PIPEMANUFACTURER'S INSTALLATION
INSTRUCTIONS.
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
finishedwall, it maybe easier tomark both theinside and outside

9
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-allorsabre saw blade.Cutaround the markedcircle 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.
6. Slide the wall plate over the pipe to stop against intake vent
terminal.
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.
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.
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 (Figure 10).
EXHAUST VENT TERMINAL
INTAKE VENT TERMINAL
FIGURE 10
VERTICAL VENT TERMINAL INSTALLATION
IMPORTANT
WHEN TERMINATING THROUGH A ROOF, THE FOLLOWING
SPECIFICATIONS PERTAINING TOTERMINALLOCATION 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 ventterminal isinstalled usingthe sameprocedure.
INSTALLATION SEQUENCE
NOTE: BEFOREBEGINNINGINSTALLATIONOFANYVENTPIPE,
READ “VENT PIPE PREPARATION” SECTION ON PAGES 10 &
11.
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.
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.
3. Suspend the pipe through the center of the hole using proper
support.
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
as shown in Figure 11.
FIGURE 11

10
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,DRYERSORSPACE HEATERS). IT IS CRUCIALTHAT
THE VENTING ARRANGEMENT BE KEPT SEPARATE FROM
OTHER VENTING SYSTEMS. IF THIS WARNING IS IGNORED,
AND THE SYSTEM IS VENTED INCORRECTLY, IT MAY CAUSE
IMPROPEROPERATION, FIRE, EXPLOSION, OR ASPHYXIATION.
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.
Table 2. VENT LENGTH TABLE
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
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. A reducing coupling is also required
immediately before the 3-inch blower adapter (intake) if direct
venting is installed.
IMPORTANT
Whenmultiple units aredirect vented througha wall (4-inchventing),
allintake vent terminals should beno lowerthan the highest exhaust
vent terminal.
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 beequivalent toPVC-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.
5. It is important that condensate not be allowed to buildup in the
exhaustventpipe. Topreventthis from happeningthepipe should
be installed with a slight, 1/8 inch (3mm) per 5 feet (152 cm) of
pipe maximum downward slope.
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.
FIGURE 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.
Number 4" PVC
of 90° Maximum Maximum
Elbows Feet. of Pipe Meters of Pipe
ONE (1) 75' 22.9m
TWO (2) 70' 21.3m
THREE (3) 65' 19.8 m
FOUR (4) 60' 18.3 m
FIVE (5) 55' 16.8 m
SIX (6) 50' 15.2 m
OUTLET VIEW
INLET VIEW

11
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.
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
WELL-VENTILATED 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
shutthe unitdown wheneverthere isa failure of any of the switches.
It is important to understand the purpose of each switch.
BLOWER PROVER SWITCH
(SEE FIGURE 13)
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
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.
BLOCKED OUTLET PROVER SWITCH
(SEE FIGURE 13)
The Blocked Outlet Prover Switch is set up to shut the unit off
whena build-up ofpositive pressurein the exhaustvent pipeoccurs.
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.
BLOCKED INLET PROVER SWITCH
(SEE FIGURE 13)
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
flangeconnectedto the inletofthe blower.Whenthisswitchprevents
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.
LOW GAS PRESSURE SWITCH
(SEE FIGURE 13)
TheLow GasSwitch (LGS)is asingle-pole, normallyopen 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.
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.
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.
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.
NOTE: LOW GAS IS
LOCATED ON INLET
SIDE OF GAS VALVE.

12
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.
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)
pressuredrop, which is considered normal for lowpressure systems
Note that fittings such as elbows and tees will add to the pipe
pressure drop.
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)
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
FIRE OR EXPLOSION. IF OVERPRESSURE HAS OCCURRED
SUCH AS THROUGH IMPROPER TESTING OF GAS LINES OR
EMERGENCY MALFUNCTION OF THE SUPPLY SYSTEM THE
GASVALVE MUST BECHECKED FOR SAFEOPERATION. MAKE
SURE THAT THE OUTSIDE VENTS ON THE SUPPLY
REGULATORS AND THE SAFETY VENT VALVES ARE
PROTECTEDAGAINSTBLOCKAGE.THESE ARE PARTSOFTHE
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.
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.
TO TRAP ANY DIRT OR FOREIGN MATERIAL IN THE GAS
SUPPLY LINE, A DIRT LEG (SOMETIMES CALLED A SEDIMENT
TRAPOR DRIP LEG) MUST BE INCORPORATED INTHE PIPING
(SEE FIG. 14). THE DIRT LEG MUST BE READILY ACCESSIBLE
AND NOT SUBJECT TO FREEZING CONDITIONS. INSTALL IN
ACCORDANCE WITH RECOMMENDATIONS OF SERVING GAS
SUPPLIERS. REFER TO THE NATIONAL FUEL GAS CODE.
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.
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.
Bubblesindicate gasleak. 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.
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
LENGTH NORMAL IRON PIPE SIZES (INCHES)
IN INPUT IN THOUSANDS BTU/HR
FEET 1/2" 3/4" 1" 1 1/4" 1 1/2" 2" 2 1/2" 3" 4"
10 175 360 680 1400 2100 3960 6300 11000 23000
20 120 250 485 950 1460 2750 4360 7700 15800
30 97 200 375 770 1180 2200 3520 6250 12800
40 82 170 320 660 990 1900 3000 5300 10900
50 73 151 285 580 900 1680 2650 4750 9700
60 66 138 260 530 810 1520 2400 4300 8800
70 61 125 240 490 750 1400 2250 3900 8100
80 57 118 220 460 690 1300 2050 3700 7500
90 53 110 205 430 650 1220 1950 3450 7200
100 50 103 195 400 620 1150 1850 3250 6700
125 44 93 175 360 550 1020 1650 2950 6000
150 40 84 160 325 500 950 1500 2650 5500
175 37 77 145 300 460 850 1370 2450 5000
200 35 72 135 280 430 800 1280 2280 4600
LENGTH NORMAL IRON PIPE SIZES (INCHES)
IN INPUT IN KW
METERS 1/2" 3/4" 1" 1 1/4" 1 1/2" 2" 2 1/2" 3" 4"
3.0 51 105 199 410 615 1160 1845 3221 6735
6.1 35 73 142 278 428 805 1277 2255 4626
9.1 28 59 110 225 346 644 1031 1830 3748
12.2 24 50 94 193 290 556 878 1552 3192
15.2 21 44 83 170 264 492 776 1391 2840
18.3 19 40 76 155 237 445 703 1259 2577
21.3 18 37 70 143 220 410 659 1142 2372
24.4 17 35 64 135 202 381 600 1083 2196
27.4 16 32 60 126 190 357 571 1010 2108
30.5 15 30 57 117 182 337 542 952 1962
38.1 13 27 51 105 161 299 483 864 1757
45.7 12 25 47 95 146 278 439 776 1610
53.3 11 23 42 88 135 249 401 717 1464
61.0 10 21 40 82 126 234 375 688 1347

13
PRESSURESOF 1/2PSIG (3.45Kpa)OR LESS,THE APPLIANCE
NEED NOT BE DISCONNECTED, BUT MUST BE ISOLATED
FROM THE SUPPLY PRESSURE TEST BY CLOSING THE
MANUAL GAS SHUTOFF VALVE.
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.
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
RISKOFFIRE OR EXPLOSION,PURGE DISCHARGE MUSTNOT
ENTER CONFINED AREAS OR SPACES WHERE IGNITION CAN
OCCUR. THE AREA MUST BE WELL VENTILATED AND ALL
SOURCESOFIGNITION MUST BEINACTIVATED 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.
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. A service regulator should be installed within
10' (305 cm) of the unit.
GAS VALVES
WARNING
SHOULD OVERHEATING OCCUR OR THE GAS SUPPLY FAIL
TO SHUT OFF, TURN OFF THE MANUAL GAS CONTROL VALVE
TO THE APPLIANCE.
SYSTEM CONNECTIONS
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.
Thermometers are installed in the system as a means of detecting
the temperature of the outlet water supply.
RELIEF VALVE
Thisheater is equipped with an approved temperature and pressure
reliefvalve. ASME ratingscover pressure relief.A.G.A. ratings cover
release rate with temperature actuation.
FOR SAFE OPERATION OF THE WATER HEATER, THE RELIEF
VALVE(S) MUST NOT BE REMOVED OR PLUGGED.
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
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
REDUCEDFROM THESIZE OFTHE VALVE OUTLETAND 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.
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
circulationmay beeither bygravity orby meansof circulatingpump.
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.
CLOSED SYSTEM
CAUTION
A closed system will exist if a check valve (without bypass),
pressurereducing 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).
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.
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.
WATER (POTABLE) HEATING AND SPACE HEATING
1. All piping components connected to this unit for space
heating applications shall be suitable for use with potable
water.

14
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.
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 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 and local requirements.
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 and/or the
CSA C22.1 Electrical Code.
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.
FIGURE 15
WHC1202 INTEGRATED WATER HEATER CONTROL
CONNECTION DIAGRAM

15
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.
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 remainon fora shortpredetermined 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
Possible Cause Remedy
1. Burner groundwirebroken 1. Checkwire andconnection
orcorroded atburner
2. Connectors unplugged 2. Checkconnections
3. Igniter broken 3. Replaceigniter
4. Flame probefaulty 4. Replaceflame probe
5. Gas shut off 5. Turnongas supply
6. Cloggedgas valve 6. Replacegas valve
7. Faultygas valve 7. Replacegas valve
8. Defective control 8. Replacecontrol
9. Burner improperlyadjusted 9. Adjust burner
10. Dirty burner 10. Cleanburner
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
Thiscontroller is designedfor ignition lockoutafter 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 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.

16
ERROR CODES
ThefollowingErrorCodesareexternal to the controller.
01 Pressure Switch FailOn,shouldbe Off
11 Pressure Switch Fail Off,shouldbeOn
02 IgnitionFailafter3attempts
04 ECOOpen
05 TemperatureProbeOpen
15 Temperature Out of Bounds<30degrees
25 Temperature Out of Bounds>220degrees
ThefollowingErrorCodesareinternaltothe controller.
113 FlameOnShouldbeOffFail
22 IgnitionRelayFailisOn,shouldbeOff
112 IgnitionRelayFailisOff,shouldbeOn
101 K2 Fail in K1
102 Main Loop Fail inK2
103 K1 Fail in MainLoop
GasValve 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 GasValveRelayFailisoff,should be On
117 GasValveRelayFailisOn,shouldbeOff
ChecksTheROM(ReadOnlyMemory).
200 CRC Check Sum Error
ChecksTheCPU(CentralProcessingUnit).
201 CPU Instruction Test Error
202 CPU Instruction Test Error
203 CPU Instruction Test Error
CheckstheRAM(RandomAccessMemory).
205 RAM TestFail
SW Check to see what the Last State it was in.
ie.,Failsif 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
TheseStateNumbersarenotused.
230 ExecutedState3(NotImplemented) h.s.
240 ExecutedState4(NotImplemented) h.s
210 ExecutedState10(NotImplemented) h.s.
213 ExecutedState13(NotImplemented) h.s.
214 ExecutedState14(NotImplemented) h.s.
216 ExecutedState16(NotImplemented) h.s.
FAULT CONDITIONS
ThecontrollerissetuptoprovideadditionalstatusindicatorsunderFault
Conditions.Thefollowingfiguresare possible Fault Conditions.
NO INCOMING LINE VOLTAGE (Figure 18)
Line LED Off
NO INCOMING LINE VOLTAGE, Line LED Off
FIGURE 18
Possible Cause Remedy
1. Transformerwiringproblem 1. Repair Wiring
2. DefectiveTransformer 2. ReplaceTransformer
3. LEDburnedout 3. Ignoreor replacecontrol
Possible Cause Remedy
1. NoInputPower 1. ApplyPower
2. Wiring Disconnected 2. Checkallwiring
3. One ormorewiring receptacles 3. Reconnectplugsoncontrol,
disconnectedfromcontrol confirm allarefullyseated
4. LED burnedout 4. Ignoreor replacecontrol
NO LOW VOLTAGE (Figure 19)
24V AC LED Off
NO LOW VOLTAGE, 24V AC LED Off
FIGURE 19
NOTE: The transformer is of Class II variety and has an internal non-
replaceable fuse. If blown, a problem may exist with the control which is
affectingthetransformer. In suchcases,thecontrolshould bereplacedas
well.
TEMPERATURE PROBE FAULT(Figure20)
Water TempLEDFlashing
TEMPERATURE PROBE FAULT, Water Temp LED Flashing
FIGURE 20
Thisconditionaccommodatesmultiplefailure modes. Tomoreaccurately
determinethecause offailure,pressthepush-buttononthedisplayboard.

17
Display Flashes “05”when button is pressed:
DisplayFlashes“15”whenbutton ispressed:
DisplayFlashes“25”whenbutton ispressed:
ECO SWITCH OPEN (Figure 21)
ECOLEDFlashing:
ECOSWITCHOPEN,ECOLEDFlashing
FIGURE21
CONTROL BAD (Figure 22)
All LEDs Flashing:
Possible Cause Remedy
1. This indicatesthecontrol has 1. Pressbutton on the
failedonofits internal displayboardto reset
diagnostic self-tests. control. If this error
occursrepeatedly,
replacecontrol.
CONTROLBAD,AllLEDs Flashing
FIGURE22
COMBUSTION AIR BLOCKAGE (Figure 23)
PressureSwitchLEDFlashing:
COMBUSTIONAIRBLOCKAGE,Pressure Switch LED Flashing
FIGURE 23
Possible Cause Remedy
1. Temperature Probe wiring 1. RepairWiring
open
2. Defective probe 2. Replaceprobe
Possible Cause Remedy
1. Nowaterintank and tank 1. Thesymptom doesnot
infreezingconditions reflect acontrolproblem
2. Waterintankabovefreezing 2. Temperatureprobeout of
tolerance,replacetemp.
probe
Possible Cause Remedy
1. Water in tank is low, probe 1. Fill tank
immersedinsteam
2. Probewiringshorted 2. Repairwiring
3. Defective probe 3. Replaceprobe
Possible Cause Remedy
1. Temp. Probeunplugged 1. Checkconnectors
2. Temp.probewiring damaged 2. Repairwiring
3. Waterintanktoo hot 3. Normalconditionwhen
water temperature
exceeds safety limit.
Allow water to cool or
admitwaterinto tankand
manuallyresetthe control.
Determine cause for
overtempcondition.
Possible Cause Remedy
1. Combustionair blocked 1. Checkexhaust pipingand
flueforobstructions
2. Blowernot operating: 2. a.Repairwiring
a.Checkblower wiring b.Replaceblower motor
b.Checkblower motor
3. Defectiveair switch 3. Replaceairswitch
4. Pressure switchjumpedout 4. This controller must sense
anopencontact onthe
blowerprovingairflow
switchbeforethe blower
comeson.Checkto see if
blowerprovingairflow
switchisstillconnected to
theunit.

18
DO NOT USE THIS HEATER IF ANY PART HAS BEEN UNDER
WATER. IMMEDIATELY CALL A QUALIFIED SERVICE
TECHNICIANTOINSPECTTHE HEATER AND TO REPLACEANY
PART OF THE CONTROL SYSTEM AND ANY GAS CONTROL
WHICH HAS BEEN UNDER WATER.
LIGHT THE UNIT IN ACCORDANCE WITH THE OPERATING
INSTRUCTIONS LABEL ATTACHED TO THE HEATER.
THESEINSTRUCTIONS ARE REPEATEDIN THE LIGHTING AND
OPERATING LABEL ILLUSTRATION ON PAGE 20 IN THIS
MANUAL.
ADJUSTMENT PROCEDURE - INITIAL START-UP
A minimum 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
resultinoverfiring of the heaterwhenthe gas supply pressurereturns
to normal.
1. Check gas line pressure with a manometer.
2. Check manifoldpressure (see Table4, page 20)usinga pressure
gauge (manometer) connected to the manifold pressure tap on
the gas control valve, (Figure 15).
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
increaseor counterclockwise to decreasegas pressure toobtain
5.0" W.C. (1.25 kPa) for Natural Gas and 10" W.C. (2.49 kPa) for
LP gas.
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:
For appliance installation locations with elevations above 2000 feet
(610 m) refer to HIGH ALTITUDE INSTALLATIONS section of this
manual.
a. Attach a pressure gauge (manometer) to the manifold
pressure tap (Figure 16) and refer to Table 4, page 20 for
correct pressure.
b. Use this formula to “clock” the meter. Be sure other gas
consuming appliances are not operating during this interval.
3600
T
T= Timeinseconds to burn1 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 = ?
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:
PRIOR TO START UP - REQUIRED ABILITY
INSTALLATIONORSERVICEOFTHISWATERHEATERREQUIRES
ABILITYEQUIVALENT TOTHAT OF A LICENSED TRADESMANIN
THE FIELD INVOLVED. PLUMBING, AIR SUPPLY, VENTING, GAS
SUPPLYANDELECTRICALWORKAREREQUIRED.
Beforeattempting start-up, thoroughly study and familiarize yourself
with the exact sequence of operation and all other details on the
specific heater being used.
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.
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.)
– 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.
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.
CAUTION
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.
NEVER OPERATE THE HEATER WITHOUT FIRST BEING
CERTAIN IT IS FILLED WITH WATER AND A TEMPERATURE
ANDA PRESSURE RELIEFVALVE ISINSTALLED INTHE RELIEF
VALVE OPENING OF THE HEATER. DO NOT ATTEMPT TO
OPERATE HEATER WITH COLD WATER INLET VALVE CLOSED.
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.
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.SEETHE FRONT PAGEFORSTEPS TOBETAKEN.
X H = Btuh 3600 X 1050 = 300,000 Btuh (87.9 kW)
12.6

19
LIGHTING AND OPERATION INSTRUCTIONS
A. This appliance does not have a pilot. It is equipped with an
ignition device which automatically lights the burner. Do
not try to light the burner by hand.
B. BEFORE OPERATING smell 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.
“WHATTO DO IFYOU SMELL GAS”
•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
IF YOU DO NOT FOLLOW THESE INSTRUCTIONS EXACTLY A FIRE OR EXPLOSION
MAY RESULT CAUSING PROPERTY DAMAGE, PERSONAL INJURY OR LOSS OF LIFE.
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
automaticallylightstheburner. Do nottry tolight theburner
by hand.
5. Push in gas control knob slightly and turn clockwise
to“OFF”.
6. Wait five (5) minutes to clear out any gas. If you then
smellgas, STOP! Follow“B”in the safety information
aboveon thislabel. Ifyoudon’t smell gas,go on to the
next step.
7. Turn gas control knob counterclockwise to“ON”.
8. Turn on all electric power to the appliance.
FOR YOUR SAFETY READ BEFORE OPERATING
OPERATING INSTRUCTIONS
WARNING
department.
C. Use only your hand to pushin or turnthe gas control knob.
Never use tools. If the knob will not push in or turn by
hand,don’ttryto repairit,calla qualifiedservicetechnician.
Force or attempted repair may result in fire or explosion.
D. Do not use this appliance ifany part hasbeen under water.
Immediately call a qualified service technician to inspect
theapplianceand toreplace anypartof the control system
and any gas control which has been under water.
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.
FOR YOUR SAFETY READ BEFORE OPERATING
9. Set thermostat to desired setting.
10. If the appliance will not operate,follow the instructions“To
TurnOffGasTo Appliance”andcall yourservicetechnician
or gas supplier.
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.
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.
e. Repeat steps (c) and (d) until the specified input rate is
achieved.
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.

20
WARNING
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. 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.
PRECAUTIONS
IF THE UNIT IS EXPOSED TO 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 FIRING
3. DAMAGE
4. FIRING WITHOUT WATER
5. SOOTING
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.
SHOULD OVERHEATING OCCUR OR THE GAS SUPPLY FAIL
TOSHUT OFF,TURN OFFTHE MANUALGAS CONTROLVALVE
TO THE APPLIANCE.
GENERAL INFORMATION
POWER BURNER
The initial start-up procedure of the unit is provided on page 18
& 19.
The sequence of operation of the unit is provided on page 15.
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.
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).
HIGH ALTITUDE INSTALLATIONS
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 [phone] FOR
REQUIREMENTS.
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.
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.
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).
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.
MAINTENANCE SCHEDULE
Following are the instructions for performing some of the
recommendedmaintenance. Unitinspection andadjustment should
be performed by a competent technician.
COMPONENT OPERATION INTERVAL REQUIRED
Tank Sediment Monthly Flushing
Removal
Tank LimeScale Semi UN-LIME®
Removal Annually Delimer
PoweredAnode Inspect Semi
System Annually
ReliefValve Inspect Semi
Annually
SAE No. 20
Circulating Oiling FourMonths non-detergent
Pump(1) motoroil
CleanInlet
Blower Screenand AsRequired SoftBrush
BlowerWheel
VentSystem Inspect Every3 Joints should
Months besealed
(1) If furnished with oiling provision.
TABLE 4.
GAS SUPPLY SPECIFICATIONS Nat. Gas LP Gas
Max.GasSupply Pressure W.C. 11.00 14.00
Max.GasSupplyPressurekPa 2.74 3.49
NominalGasSupplyPressureW.C. 7.00 11.00
NominalGasSupplyPressurekPa 1.74 2.74
MinimumGasSupply Pressure W.C.* 6.20 11.0
MinimumGasSupplyPressurekPa* 1.54 2.74
ManifoldGasSupplyPressureW.C. 5.00 10.0
ManifoldGasSupplyPressurekPa 1.25 2.49
*Minimumpressure for purposesofrateadjustment