A.O. Smith BTH 120-250A User Manual

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CYCLONE XHE® Model BTH 120-250(A)

SERIES 970 AND 973

COMMERCIAL GAS WATER HEATER

GAS-FIRED POWER BURNER

FOR DOMESTIC HOT W A TER

• INST ALLATION • OPERA TION • SER VICE • MAINTENANCE • LIMITED W ARRANTY

W ARNING: 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 .

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 IN BLACK BOLD TYPE OR UNDERLINED CONTAINS INFORMATION RELATIVE TO YOUR SAFETY. PLEASE READ THOROUGHL Y BEFORE INST ALLING AND USING THIS APPLIANCE.

PLACE THESE INSTRUCTIONS ADJACENT TO HEA TER AND

NOTIFY OWNER TO KEEP FOR FUTURE REFERENCE.

PRINTED IN U.S.A. 110 4 PART NO. 196145-001

A DIVISION OF A.O. SMITH CORPORATION

Mc BEE, SOUTH CAROLINA

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CYCLONE XHE BTH 120 - 250 ROUGH-IN-DIMENSIONS

GAS VAL VE PIPING

BTH-120 1/2" NPT BTH-150,

199 & 250 3/4" NPT

T able 1. RECOVERY CAP ACITIES - NA TURAL GAS / L.P.

Input Gallon

Approx.

Model BTU/Hr. Capacity 30 40 50 60 70 80 90 100 110 120 130 140 BTH - 120 125,000 Nat. 60 475 356 285 237 203 178 158 142 129 119 110 102 BTH - 120 120,000 L.P. 60 456 342 274 228 195 171 152 137 124 114 105 98

BTH - 150 150,000 Nat. 100 570 427 342 285 244 214 190 171 155 142 132 122 BTH - 150 150,000 L.P. 100 570 427 342 285 244 214 190 171 155 142 132 122 BTH - 199 199,900 Nat. 100 759 569 456 380 325 285 253 228 207 190 175 163 BTH - 199 185,000 L.P. 100 703 527 422 351 301 263 234 211 192 176 162 151 BTH - 250 240,000 Nat. 100 912 684 547 456 391 342 304 274 248 228 210 195

Approx.

Input Liter

Model kW Capacity 17°C 22°C 28°C 33°C 39°C 44°C 50°C 56°C 61°C 67°C 72°C 78°C BTH - 120 37 Nat. 227 1798 1348 1079 898 768 674 598 538 488 450 416 386 BTH - 120 35 L.P. 227 1726 1295 1037 863 738 647 575 519 469 432 397 371 BTH - 150 44 Nat. 379 2158 1616 1295 1079 924 810 719 647 587 538 500 462 BTH - 150 44 L.P. 379 2158 1616 1295 1079 924 810 719 647 587 538 500 462 BTH - 199 58 Nat. 379 2873 2154 1726 1438 1230 1079 958 863 784 719 662 617 BTH - 199 54 L.P. 379 2661 1995 1597 1329 1139 996 886 799 727 666 613 572 BTH - 250 70 Nat. 379 3452 2589 2071 1726 1480 1295 1151 1037 939 863 795 738

Recovery capacities are based on heater performance at 94% thermal efficiency.

TEMPERATURE RISE - DEGREES °F - GALLONS PER HOUR

TEMPERATURE RISE - DEGREES °C - LITERS PER HOUR

FOREWORD

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 M 98 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, NFP A 70 CAN/CSA 149.1 or .2 and CSA 2C22.1. The former is available from the CSA International, 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.

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TABLE OF CONTENTS

PAGE PAGE

ROUGH-IN DIMENSIONS ................................................................... 2

FOREWORD...................................................................................... 2

FEATURES ........................................................................................ 3,4

Water Temperature Control .......................................................... 3

High Limit Switch (E.C.O.) ............................................................ 4

Dishwashing Machine Requirement ............................................ 4

Circulating Pump........................................................................... 4

INSTALLA TION INSTRUCTIONS ........................................................ 4-13

Required Ability ............................................................................ 4

Insulation Blankets ....................................................................... 4,5

Locating The Heater..................................................................... 5

Clearances ................................................................................... 5

Hard Water ................................................................................... 6

Air Requirements ......................................................................... 6

Mechanical Exhausting of Room Air............................................ 6

Unconfined Space ....................................................................... 6

Confined Space ........................................................................... 6

Chemical Vapor Corrosion ........................................................... 6

Venting ......................................................................................... 6

Vent Pipe Termination ................................................................... 6-8

Direct Venting............................................................................... 8

Direct Vent Terminal Installation (Sidewall) ................................. 8

Installation Sequence................................................................... 9

Vertical Vent Terminal Installation ................................................ 10

Installation Sequence................................................................... 10

Installation of Vent System .......................................................... 10 ,11

Vent Pipe Preparation................................................................... 11

CONTROL AND SWITCHES .............................................................. 11,12

Blower Prover Switch ................................................................. 11

Blocked Outlet Prover Switch...................................................... 12

Blocked Inlet Prover Switch......................................................... 12

Low Gas Pressure Switch .......................................................... 12

On/Off Switch .............................................................................. 12

Hot Surface Igniter ....................................................................... 12

GAS PIPING....................................................................................... 12

Connection of Gas Pipe ............................................................... 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 ............................................................. 14

Heater Wiring .............................................................................. 14

OPERA TION...................................................................................... 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

T emperature Probe Fault............................................................. 16

E.C.O. Switch Open .................................................................... 17

Control Bad.................................................................................. 17

Combustion Air Blockage............................................................ 17

PRIOR TO ST ART-UP ....................................................................... 18

Required Ability ........................................................................... 18

OPERATIING INSTRUCTIONS ........................................................... 18

Adjustment Procedure (Initial Start-Up) ...................................... 18

Lighting Instructions .................................................................... 19

Cathodic Protection ..................................................................... 20

Precautions ................................................................................. 20

GENERAL INFORMA TION ................................................................ 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

Anode Inspection and Replacement........................................... 21,22

Drain Valve and Access Panels ................................................. 22

Relief Valve ................................................................................. 22

Circulating Pump.......................................................................... 22

Vent System ................................................................................ 22

INSTALLA TION DIAGRAMS............................................................. 23 - 27

Manifold Kits................................................................................ 28

CHECKLIST AND SERVICE INFORMATION ...................................... 29

TROUBLE-SHOOTING...................................................................... 29,30

REPLACEMENT PAR TS .................................................................... 30

LIMITED WARRANTY....................................................................... 31

FEATURES

IMPORT ANT

IT IS REQUIRED THA T A QUALIFIED SER VICE 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 T O THE OPERA TION AND MAINTENANCE OF THE UNIT .

A CHECKLIST AND SERVICE INFORMA TION 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.

WA TER TEMPERA TURE CONTROL

DANGER

THIS WA TER HEA TER IS EQUIPPED WITH AN ADJUSTABLE THERMOST A T TO CONTROL W ATER TEMPERATURE. HOT WA TER TEMPERATURES REQUIRED FOR AUTOMATIC DISHW ASHER AND LAUNDRY USE CAN CAUSE SCALD BURNS RESUL TING IN SERIOUS PERSONAL INJURY AND/ OR DEATH. THE TEMPERATURE AT WHICH INJUR Y OCCURS VARIES WITH THE PERSON’S AGE AND THE TIME OF THE 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 WA TER HEATER SHOULD BE LOCATED IN AN AREA WHERE THE GENERAL PUBLIC DOES NOT HA VE ACCESS TO SET TEMPERA TURES.

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.

The temperature may be adjusted from 80°F/27°C to 185°F/85°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,

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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.

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/11°C. If you experience this type of use, you should consider using lower temperature settings to reduce scald hazards.

Temperature Time to Produce 2nd & 3rd

Setting Degree Burns on Adult Skin 180°F / 82°C Nearly instantaneous 170°F / 77°C Nearly instantaneous 160°F / 71°C About 1/2 second 150°F / 66°C About 1-1/2 seconds 140°F / 60°C Less than 5 seconds 130°F / 54°C About 30 seconds 120°F / 49°C More than 5 minutes

FIGURE 1

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.

Continued manual resetting of high limit control, preceded by higher than usual water temperature is evidence of high limit switch operation. The following are possible reasons 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 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.)

CIRCULA TING 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 NFPA 70 or Canadian Code CSAC22.1.

All bronze circulators are recommended for used with commercial water heaters.

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. T he water temperature must drop below 160°F/71°C before the controller can be reset.

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

INST ALLATION OR SERVICE OF THIS WA TER 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.

INSULA TION 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 90.1 1999 standards with respect to insulation and standby loss requirements, making an insulation blanket unnecessary.

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.

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• 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.

LOCA TING THE HEATER

WARNING

THERE IS A RISK IN USING FUEL BURNING APPLIANCES SUCH AS GAS WA TER HEA TERS IN ROOMS, GARAGES OR OTHER AREAS WHERE GASOLINE, OTHER FLAMMABLE LIQUIDS OR ENGINE DRIVEN EQUIPMENT OR VEHICLES ARE STORED, OPERA TED OR REP AIRED. FLAMMABLE VAPORS ARE HEA VY AND TRA VEL ALONG THE FLOOR AND MAY BE IGNITED BY THE HEA TER’S IGNITER OR MAIN BURNER FLAMES CAUSING FIRE OR EXPLOSION. SOME LOCAL CODES PERMIT OPERATION OF GAS APPLIANCES IF INST ALLED 18 INCHES (46 cm) OR MORE ABOVE THE FLOOR. THIS MA Y REDUCE THE RISK IF LOCA TION IN SUCH AN AREA CANNOT BE A VOIDED.

THE HEATER SHALL BE LOCATED OR PROTECTED SO IT IS NOT SUBJECT TO PHYSICAL DAMAGE BY A MOVING VEHICLE.

DO NOT LOCATE THE HEA TER WHERE NOISE FROM THE EXHAUST OR INTAKE WILL BE OBJECTIONABLE. THIS INCLUDES LOCATIONS CLOSE TO OR ACROSS FROM WINDOWS AND DOORS. A VOID ANCHORING THE VENT AND INT AKE PIPES DIRECTL Y TO FRAMED WALLS, FLOORS OF CEILINGS UNLESS RUBBER ISOLA TION PIPE HANGERS ARE USED. THIS PREVENTS ANY VIBRA TIONS FROM BEING TRANSMITTED INTO THE LIVING SPACES.

• Devices that will turn off the gas supply to a gas water heater while at the same time shutting off its water supply.

WARNING

THIS WA TER HEA TER IS A CONDENSING UNIT AND REQUIRES A DRAIN TO BE LOCATED IN CLOSE PROXIMITY TO ALLOW THE CONDENSATE T O DRAIN SAFEL Y. THE CONDENSATE DRAINS FROM THE UNIT A T THE EXHAUST ELBOW LOCA TED AT THE BOTT OM OF THE UNIT . NOTE: IT IS IMPORTANT THA T THE CONDENSA TE HOSE NOT BE ELEVATED ABOVE THE EXHAUST ELBOW (SEE FIGURE 3). THE CONDENSATE BUILD-UP WILL BLOCK THE EXHAUST OUTLET, WHICH WILL CAUSE IMPROPER OPERA TION.

FIGURE 3

WARNING

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 MA TERIAL 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 HEA TER MUST NOT BE LOCATED IN AN AREA WHERE IT WILL BE SUBJECT TO FREEZING.

LOCATE IT NEAR A FLOOR DRAIN. THE HEA TER SHOULD BE LOCA TED IN AN AREA WHERE LEAKAGE FROM THE HEA TER OR CONNECTIONS WILL NOT RESULT IN DAMAGE T O 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.

Water heater life depends upon water quality, water pressure and the environment in which the water heater is installed. Water heaters are sometimes installed in locations where leakage may result in property damage, even with the use of a drain pan piped to a drain. However, unanticipated damage can be reduced or prevented by a leak detector or water shut-off device used in conjunction with a piped drain pan. These devices are available from some plumbing supply wholesalers and retailers, and detect and react to leakage in various ways:

WARNING

DO NOT USE THIS APPLIANCE IF ANY P ART HAS BEEN UNDER WA TER. IMMEDIATEL Y CALL A QUALIFIED SERVICE TECHNICIAN T O INSPECT THE APPLIANCE AND TO REPLACE ANY PART OF THE CONTROL SYSTEM AND ANY GAS CONTROL WHICH HAS BEEN UNDER W A TER.

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, flue baffles, flue damper devices, thermostats, cleanout openings or drain valves.

Always disconnect electrical power before servicing the unit

• Sensors mounted in the drain pan that trigger an alarm or turn off the incoming water to the water heater when leakage is detected.

• Sensors mounted in the drain pan that turn off the water supply to the entire home when water is detected in the drain pan.

• Water supply shut-off devices that activate based on the water pressure differential between the cold water and hot water pipes connected to the water heater.

FIGURE 4

*ILLUSTRATION OF MINIMUM COMBUSTIBLE CLEARANCES IN AN

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ALCOVE

HARD WA TER

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.

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 RESUL T IN A YELLOW , LUMINOUS BURNER FLAME, CAUSING CARBONING OR SOOTING OF THE COMBUSTION CHAMBER, BURNERS AND FLUE TUBES AND CREATES A RISK OF ASPHYXIA TION.

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 (6.5 cm²) per 4000 Btuh 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 (6.5 cm²) per 2000 Btuh of the total input of all appliances in the enclosure.

CHEMICAL V APOR CORROSION

WARNING

CORROSION OF THE FLUE WAYS AND VENT SYSTEM MAY OCCUR IF AIR FOR COMBUSTION CONTAINS CERT AIN CHEMICAL VAPORS. SUCH CORROSION MA Y RESUL T IN F AILURE 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. IF NECESSAR Y , UNCONTAMINATED AIR SHOULD BE OBTAINED FROM REMOTE OR OUTSIDE SOURCES.

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 INTO THE ROOM THROUGH THE HEATER’S VENTING SYSTEM, CAUSING POOR COMBUSTION. SOOTING MA Y RESUL T IN SERIOUS DAMAGE TO THE HEA TER AND RISK OF FIRE OR EXPLOSION. IT CAN ALSO CREA TE A RISK OF ASPHYXIA TION.

UNCONFINED SP ACE

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 (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.

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 (6.5 cm²) per 1000 Btuh appliances in the enclosure, but not

VENTING

WARNING

THE INSTRUCTIONS IN THIS SECTION ON VENTING MUST BE FOLLOWED TO A VOID CHOKED COMBUSTION OR RECIRCULA TION OF FLUE GASES. SUCH CONDITIONS CAUSE SOOTING OR RISKS OF FIRE AND ASPHYXIATION.

Heater must be protected from freezing downdrafts during shutdown periods.

WARNING

NEVER OPERATE THE HEA TER UNLESS IT IS VENTED TO THE OUTDOORS AND HAS ADEQUATE AIR SUPPLY TO AVOID RISKS OF IMPROPER OPERATION, FIRE, EXPLOSION OR ASPHYXIA TION.

VENT PIPE TERMINATION

NOTE: Before installing venting, determine place of vent pipe termination. See Figure 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 VIBRA TIONS FROM BEING

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DIRECT VENT

DO NOT TERMINATE EXHAUST OVER PUBLIC AREA WHERE CONDENSATE OR VAPOR CAN CAUSE NUISANCE OR HAZARD.

FIGURE 5

HORIZONTAL VENT

*NOTE: BTH 250 USES TEE ON

AIR INTAKE TERMINAL

ON DIRECT VENT INST ALLA TIONS, EXHAUST VENT HOOD MUST BE LOCATED 1' (30.5cm) MINIMUM FROM ANY OPENING IN BUILDING.

ON DIRECT VENT INSTALLA TIONS, EXHAUST VENT HOOD MUST BE LOCATED 4' (122cm) MINIMUM FROM ANY OPENING IN BUILDING.

FIGURE 6

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TRANSMITTED INTO THE LIVING SP ACES.

IMPORT ANT

The vent system must terminate so that proper clearances are maintained as cited in local codes or the latest edition of the 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 not terminate the exhaust vent terminal over public area where 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 horizontal the venting system, using room for 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.

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.

THE AIR INTAKE (see Figure 8) PROVIDED ON THE UNIT .

FIGURE 8

DIRECT VENT TERMINAL INST ALLATION

IMPORT ANT

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 (OR 3" PVC TEE FOR BTH 250) WITH A MESH WIRE SCREEN AND THE EXHAUST VENT TERMINAL IS A 3" 45°PVC ELBOW WITH A MESH WIRE SCREEN.

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.

IMPORT ANT

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. TERMINA TION 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) to prevent large particles from entering the unit.

3" (7.6cm) 45° PVC ELBOW WITH MESH SCREEN

NOTE: TO PREVENT EXHAUSTING PRODUCTS FROM CIRCULA TING T O THE AIR INTAKE IN WINDY/COLD AREAS, THE MAXIMUM PRACTICAL

DISTANCE BETWEEN THESE TWO TERMINALS IS RECOMMENDED.

BTH 120

BTH 150

& 199

FIGURE 7

WARNING

WHEN THE UNIT IS TO BE SETUP AS A DIRECT VENT , THE MESH SCREEN MUST BE REMOVED. THE INLET VENT PIPE MA Y THEN BE GLUED TO

BTH 250

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FIGURE 9

IMPORT ANT

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 will reduce possibility of frost over from side winds blowing exhaust vapors to the air intake of the direct the vent.

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).

INST ALLATION 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 INST ALLATION OF ANY VENT PIPE READ THE VENT PIPE MANUFACTURER'S INST ALLA TION 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 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 3" 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).

FIGURE 10

Page 10

FIGURE 11

VERTICAL VENT TERMINAL INST ALLA TION

IMPORT ANT

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 & 12. NOTE: Exhaust vent terminal is installed using the same procedure.

INSTALLA TION SEQUENCE

NOTE: BEFORE BEGINNING INST ALLA TION OF ANY VENT PIPE, READ “VENT PIPE PREPARATION” SECTION ON PAGE 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 12.

FIGURE 12

INSTALLATION OF VENT SYSTEM

WARNING

THE OPTIONAL INTAKE VENTING ARRANGEMENT AND THE EXHAUST VENTING ARRANGEMENT MUST BE INST ALLED TO RUN DIRECTL Y TO THE OUTDOORS AND NOT IN ANY W A Y BE CONNECTED T O ANOTHER VENTING SYSTEM (I.E. FURNACE, DRYERS OR SP ACE 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 ASPHYXIA TION.

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. The installer may add up to a MAXIMUM OF FIFTY (50) EQUIVALENT FEET (15.2 m) of pipe to the exhaust venting arrangement. This addition of FIFTY (50) EQUIVALENT FEET (15.2 m) of pipe on both the intake venting arrangement and exhaust venting arrangement must include any 3" PVC elbows which equals (5) EQUIVALENT FEET (1.5 m) of pipe.

Page 11

Table 2. VENT LENGTH TABLE

Number 3" 3" 4"

of 90° Minimum Maximum Maximum

Elbows Pipe (Ft./M.) Pipe (Ft./M.) Pipe (Ft./M.)

ONE (1) 7/2 45/13.7 115/35

TWO (2) 7/2 40/12.2 110/33.5

THREE (3) 7/2 35/10.7 105/32

FOUR (4) 7/2 30/9.1 100/30.5

FIVE (5) 7/2 --- 95/29

SIX (6) 7/2 --- 90/27.4

4-inch PVC may be used for a MAXIMUM intake of ONE HUNDRED TWENTY (120) EQUIVALENT FEET (36.6m) and a MAXIMUM exhaust of ONE HUNDRED TWENTY (120) EQUIV ALENT FEET (36.6m). The maximum number of 90° elbows with the 4-inch venting is six (6) on the intake and six (6) on the exhaust. A 90° elbow is equal to five (5) equivalent feet (1.5m) of pipe. One (1) 90° elbow is equal to two (2) 45° elbows. Any venting configuration using less than 50 equivalent feet should use 3-inch venting. See Table 2.

The 3-inch venting terminals (provided) must be used with the 4-inch venting by adding 4x3 reducing couplings at the venting terminals. A reducing coupling is also needed immediately after the condensate elbow (exhaust) and immediately before the 3-inch blower adapter (intake) if direct venting is installed. See Table 2.

IMPORT ANT

When multiple units are direct vented through a wall (3-inch or 4-inch venting), all intake vent terminals should be no lower than 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 be equivalent to PVCDWV 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.

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.

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 ONL Y IN A WELL-VENTILATED AREA.

CONTROLS AND SWITCHES

The BTH-120 and 250 are provided with four pressure switches. Both the BTH 150 and 199 are provided with three 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.

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.

4. 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.

5. 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.

VENT PIPE PREP ARATION

1. INITIAL PREPARA TION 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.

NOTE: LOW GAS IS LOCATED ON INLET SIDE OF GAS VALVE.

FIGURE 13

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.

Page 12

BLOCKED OUTLET PROVER SWITCH

(SEE FIGURE 13)

The Blocked Outlet Prover Switch is set up to shut the unit off when a buildup 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. Also verify that there is no more than fifty equivalent feet (15.2 m) of three inch PVC vent pipe on the exhaust.

BLOCKED INLET PROVER SWITCH

(SEE FIGURE 13)

The Blocked Inlet Prover Switch is set up to shut the unit off when a buildup 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 PVC 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 fifty equivalent feet (15.2 m) of three 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)

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. (1.25Kpa) W.C. is encountered. The contacts will open when the pressure falls below the fixed set point of 5.0 in. (1.25Kpa) W.C. The LGS monitors the gas supply pressure to the heater. If the gas supply falls below 5.0 in. (1.25Kp a) W.C., the main burner is extinguished (if heater is running) or the heater will not start up.

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 HEA TER BE CERT AIN THA T SUPPLY NEUTRAL WIRE TO GROUND CHECK INDICA TES ZERO VOL T AGE.

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 still 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.

MAXIMUM CAP ACITY OF PIPE IN CUBIC FEET OF GAS PER HOUR

TABLE 3

(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 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 1 1 8 220 460 690 1300 2050 3700 7500

90 53 1 1 0 205 430 650 1220 1950 3450 7200 100 50 103 195 400 620 115 0 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 1 1 0 225 346 644 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

WARNING

THE HEATER IS NOT INTENDED FOR OPERA TION AT HIGHER THAN 14.0" WA TER COLUMN (1/2 POUND or 3.45Kpa PER SQUARE INCH) SUPPLY GAS PRESSURE. HIGHER GAS SUPPLY PRESSURES REQUIRE SUPPLEMENTAL REDUCING SERVICE REGULATION. EXPOSURE TO HIGHER GAS SUPPLY PRESSURE MA Y CAUSE DAMAGE T O 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 GAS VALVE MUST BE CHECKED FOR SAFE OPERATION. MAKE SURE THA T THE OUTSIDE VENTS ON THE SUPPL Y REGULATORS AND THE SAFETY VENT VALVES ARE PROTECTED AGAINST BLOCKAGE. THESE ARE PARTS OF THE GAS SUPPLY SYSTEM, NOT THE HEA TER. 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 A TTACHING THE GAS LINE BE SURE THA T ALL GAS PIPE IS CLEAN ON THE INSIDE.

TO TRAP ANY DIRT OR FOREIGN MA TERIAL IN THE GAS SUPPL Y LINE, A DIRT LEG (SOMETIMES CALLED A SEDIMENT TRAP OR DRIP LEG) MUST BE INCORPORA TED IN THE 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.

Size the main gas line in accordance with Table 3. The figures shown are for straight lengths of pipe at 0.5 in. (125Pa) W.C. 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.

CAUTION

DO NOT USE FLEXIBLE GAS PIPING.

FIGURE 14

Page 13

CONNECTION OF GAS PIPE

GAS METER SIZE - CITY GASES ONL Y

1. When connecting gas pipe to unit, apply wrench to flange only. Note: Do not use wrench on gas valve or gas bracket. See Figure 15.

2. PERFORM THE GAS LEAK TEST ANY TIME WORK IS DONE ON A GAS SYSTEM TO A VOID THE POSSIBILITY OF FIRE OR EXPLOSION WITH PROPERTY DAMAGE, PERSONAL INJURY OR LOSS OF LIFE.

FIGURE 15

The Gas Leak T est 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.

DISCONNECT THE APPLIANCE AND ITS MANUAL GAS SHUTOFF V AL VE FROM THE GAS SUPPLY PIPING SYSTEM DURING ANY SUPPLY PRESSURE TESTING EXCEEDING 1/2 PSIG (3.45Kpa). GAS SUPPL Y LINE MUST BE CAPPED WHEN DISCONNECTED FROM THE HEATER. FOR TEST PRESSURES OF 1/2 PSIG (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 W ATER SOLUTION OR OTHER MATERIAL ACCEPTABLE FOR THE PURPOSE OF LOCA TING 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 RISK OF FIRE OR EXPLOSION, PURGE DISCHARGE MUST NOT ENTER CONFINED AREAS OR SP ACES WHERE IGNITION CAN OCCUR. THE AREA MUST BE WELL VENTILATED AND ALL SOURCES OF IGNITION MUST BE INACTIVA TED OR REMOVED.

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 REGULA TION

Main line gas pressure to the water heater should be between a maximum

14.0" (3.45Kpa) W.C. and a minimum as shown in Table 4: that is, for Natural Gas, 5.0" (1.25Kpa) W.C. for BTH 120 & 250 or 4.5" (1.12Kpa) W.C. for BTH 150 & 199 or; for L.P. Gas, 11.0" (2.74Kpa) W.C. The inlet gas pressure must not exceed the maximum value. A service regulator must be installed within 10' (305 cm) of unit.

WARNING

FAILURE TO INST ALL A PRESSURE REGULA TOR WITHIN 10 FEET OF THE WA TER HEA TER CAN RESUL T IN LEAKAGE OF FLUE GASES INTO THE SURROUNDING ROOM. SERIOUS PERSONAL INJURY OR DEATH COULD RESUL T FROM INHALA TION OF CARBON MONOXIDE GAS.

GAS VAL VES

WARNING

SHOULD OVERHEA TING OCCUR OR THE GAS SUPPL Y F AIL 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 V ALVE

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.

FOR SAFE OPERATION OF THE W A TER HEA TER, THE RELIEF VAL VE(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 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 VAL VE AND THE TANK.

A DRAIN LINE MUST BE CONNECTED TO THE RELIEF V AL VE TO DIRECT DISCHARGE TO A SAFE LOCATION TO AVOID SCALDING OR WATER DAMAGE. THIS LINE MUST NOT BE REDUCED FROM THE SIZE OF THE VAL VE OUTLET AND MUST NOT CONT AIN V ALVES OR RESTRICTIONS, NOR SHOULD IT BE LOCA TED IN FREEZING AREAS. DO NOT THREAD OR CAP THE END OF THIS LINE. RESTRICTED OR BLOCKED DISCHARGE WILL DEFEAT THE PURPOSE OF THE V AL VE AND IS UNSAFE. THE DISCHARGE LINE SHALL BE INST ALLED T O ALLOW COMPLETE DRAINAGE OF BOTH THE VA LVE AND LINE.

Page 14

WA TER LINE CONNECTIONS

This manual provides detailed installation diagrams (see back section of this manual) for typical methods of application for the water heaters.

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.

The water heater may be installed by itself, or with a separate storage tank.

CLOSED SYSTEM

CAUTION

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).

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) HEA TING AND SP ACE HEA TING

1. All piping components connected to this unit for space heating applications shall be suitable for use with potable water.

2. Toxic chemicals, such as those used for boiler treatment, shall

NEVER be introduced into this system.

HEA TER 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 ST ABLE CLEAN ELECTRICITY FOR PROPER OPERATION. INST ALLING THE HEA TER ON A BRANCH CIRCUIT THA T HAS ELECTRONIC NOISE, IS SUBJECT TO FLUCTUA TIONS IN VOL TAGE 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 SUPPL Y ARE NOT COVERED UNDER YOUR WARRANTY.

The controller is wired to the heater as shown in figures 16 & 17. 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 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 T ANK IS FILLED WITH WATER.

National

3. This unit may never be connected to any existing heating system or component(s) previously used with non-potable water heating appliance.

WHC1202 INTEGRATED WATER HEATER CONTROL CONNECTION DIAGRAM

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 16

Page 15

ITEM DESCRIPTION

1. Transformer

2. Control Board & Cable Ass'y

3. E.C.O./Temperature Probe

4. Blower Proving Air Switch

5. Low Voltage Cable Assembly

6. Line Voltage Cable Assembly

7. Blower/Motor Assembly

8. Igniter Assembly 10 . Control Display Board

11. Blocked Outlet Exhaust Switch 12 . Lower Temperature Probe

13. Wire Assembly-Gas Pressure Switch

FIGURE 17

14. Tubing-Pressure

15. Tubing-Pressure

17. Switch-On/Off 18 . Low Gas Pressure Switch

(BTH 120 and 250 Only). 19 . Bocked Inlet Switch 20 . Wire Assembly-Air

Flow Switch

OPERATION

SEQUENCE OF OPERA TION

Typical Control/Appliance Operating Sequence

1. When the control is initially powered, it enters a test mode and will display the current software revision (example "104") for approximately 2 seconds, then "88.8" and all the LED's will illuminate for approximately 2 seconds. At this point, the control is in the idle mode and will display the actual tank temperature.

2. If the control determines the actual water temperature inside the tank is below the programmed temperature setpoint less one half 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 switch, ignitor, gas valve, flame sense rod, 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 (blower should continue to run).

6. During the ignitor warm-up period, the control will sense ignitor current. If ignitor current is within the specified range, the controller will energize (open) the gas valve at the end of the ignitor warm-up period, allowing gas to enter the burner chamber. If ignitor current is not within the specified range, the control will not energize the gas valve, and the control will return to Step 2 of the process. (See section below: Appliance Ignition Failure).

7. After energizing the gas valve, the control will keep the ignitor on for a short predetermined time period, then remove power to the ignitor.

8. After an additional 1 second, the control will monitor the flame sense probe to confirm a flame is present. If a flame is time period, the controller will immediately de-energize (close) the gas valve, and return to step two of the process. (See section below: Appliance Ignition Failure).

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 one half the 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 internal state of the controller. If the temperature drops below the setpoint value less one half the differential, the control will automatically return to Step 2 and repeat the entire operating cycle.

not verified within this

SELF DIAGNOSTIC CONTROLLER

A green LED is mounted on the Main Control Board to indicate line voltage polarity is properly connected. The green LED is mounted next to connector CN1 (Line input connection). When 120 VAC input power is properly connected to the Main Control Board, the green LED will illuminate. If an error is made when connecting 120 V AC input power, this LED will not light. Improperly connecting the input power may result in a false sensor failure.

The 24 VAC circuitry is protected with a 3 amp auto fuse. If the fuse opens, the LED display and discrete LED's on the Display Board assembly will not illuminate. The recommended fuse replacement part is Littlefuse p/n 257003 automotive fuse. Repeated failure of the fuse is an indication of possible damage to the Main Control Board. If repeated fuse failure occurs, return the Control Board for service.

Under normal operating conditions, should the ignitor current fall out of specification or the gas fail to light at the burner during the first trial for ignition, the control will perform two (2) more ignition trials prior to entering a lockout state. Note that each subsequent ignition trial will not occur immediately. After a failed trial for ignition, the controller will remove all power from the blower, gas valve, and ignitor and return to the call for heat state. If a call for heat is activated, the controller will energize the combustion blower for the pre-purge cycle, and again activate the ignitor to complete its warm-up period. After the warm-up period, the gas valve is opened, ignitor power removed, and the control will again check for flame.

If ignition is sensed during any one of these trials, normal operation will resume. If ignitor current should fall out of specification or flame is not sensed after the third ignition trial, the control will automatically enter a lockout state ("Loc" displayed on the Display Board) and the ignitor or gas valve LED on the Display Board will flash. The lockout state is manually reset by momentarily pressing the push-button on the Display Board. If a manual reset does not occur within a one hour time period, the controller will automatically reset the lockout condition and provided the call for heat still exists, will attempt another ignition sequence.

FIGURE 18

Page 16

GAS VAL VE 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 Remedy

1. Burner ground wire broken 1. Check wire and connection or corroded at burner

2. Connectors unplugged 2. Check connections

3. Igniter broken 3. Replace igniter

4. Flame probe faulty 4. Replace flame probe

5. Gas shut off 5. Turn on gas supply

6. Clogged gas valve 6. Replace gas valve

7. Faulty gas valve 7. Replace gas valve

8. Defective control 8. Replace control

9. Burner improperly adjusted 9. Adjust burner

10. Dirty burner 10. Clean burner

FAUL T CONDITIONS

The controller is set up to provide additional status indicators under Fault Conditons. The following figures are possible Fault Conditions.

NO INCOMING LINE VOLTAGE (Figure 19) Line LED Off

NO LOW VOLTAGE (Figure 20)

24V AC LED Off

NO LOW VOLTAGE, 24V AC LED Off

FIGURE 20

Possible Cause Remedy

1.Blower 24 VAC Fuse 1. Replace 24 VAC 3a Fuse

(Littlefuse 257003 automotive fuse).

2.Defective Transformer 2. Replace Transformer

3.LED burned out 3. Ignore or replace control

NO INCOMING LINE VOLT AGE, Line LED Of f

FIGURE 19

Possible Cause Remedy

1. No Input Power 1. Apply Power

2. Wiring Disconnected 2. Check all wiring

3. One or more wiring receptacles 3. Reconnect plugs on control, disconnected from control confirm all are fully seated

4. LED burned out 4. Ignore or replace control

TEMPERATURE PROBE FAUL T (Figure 21)

Water Temp LED Flashing

TEMPERATURE PROBE F AUL T , W ater T emp LED Flashing

FIGURE 21

This condition accommodates multiple failure modes. To more accurately determine the cause of failure, press the pushbutton on the display board.

Page 17

Display Flashes “05” when button is pressed:

Possible Cause Remedy

1. Temperature Probe wiring 1. Repair Wiring open

2. Defective probe 2. Replace probe

Display Flashes “15” when button is pressed:

Possible Cause Remedy

1. No water in tank and tank 1. The symptom does not in freezing conditions reflect a control problem

2. Water in tank above freezing 2. Temperature probe out of

tolerance, replace temp. probe

Display Flashes “25” when button is pressed:

Possible Cause Remedy

1. Water in tank is low, probe 1. Fill tank immersed in steam

2. Probe wiring shorted 2. Repair wiring

3. Defective probe 3. Replace probe

ECO SWITCH OPEN (Figure 22)

ECO LED Flashing:

CONTROL BAD, All LEDs Flashing

FIGURE 23

Possible Cause 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 temperature 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 (Figure 24)

Pressure Switch LED Flashing:

ECO SWITCH OPEN, ECO LED Flashing

FIGURE 22

Possible Cause Remedy

1. This indicates the control has 1. Press button on the failed on of its internal display board to reset diagnostic self-tests. control. If this error

occurs repeatedly, replace control.

CONTROL BAD (Figure 23)

All LEDs Flashing:

COMBUSTION AIR BLOCKAGE, Pressure Switch LED Flashing

FIGURE 24

Possible Cause Remedy

1. Combustion air blocked 1. Check exhaust piping and

2. Blower not operating: 2. a. Repair wiring a. Check blower wiring b. Replace blower motor b. Check blower motor

3. Defective air switch 3. Replace air switch

4. Pressure switch jumped out 4. This controller must sense

flue for obstructions

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.

Page 18

PRIOR TO START UP

REQUIRED ABILITY

ADJUSTMENT PROCEDURE

INITIAL ST ART-UP

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.

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" (0-2.5Kpa) and 0-35" (0-

8.7Kpa) W.C. 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 (see Figure 15).

• 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 HEA TER WITHOUT FIRST BEING CERTAIN IT IS FILLED WITH WA TER AND A TEMPERA TURE AND A PRESSURE RELIEF V AL VE IS INSTALLED IN THE RELIEF V ALVEOPENING OF THE HEATER. DO NOT ATTEMPT TO OPERA TE HEATER WITH COLD W ATER INLET V AL VE 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 VA L VE 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, MA Y INDICA TE THE PRESENCE OF ACCUMULA TED GAS SOMEPLACE IN THE AREA WITH A RISK OF FIRE OR EXPLOSION. SEE THE FRONT P AGE FOR STEPS TO BE T AKEN.

DO NOT USE THIS HEATER IF ANY PART HAS BEEN UNDER WATER. IMMEDIA TEL Y CALL A QUALIFIED SERVICE TECHNICIAN TO INSPECT THE HEATER AND TO REPLACE ANY P ART OF THE CONTROL SYSTEM AND ANY GAS CONTROL WHICH HAS BEEN UNDER W A TER.

LIGHT THE UNIT IN ACCORDANCE WITH THE OPERATING INSTRUCTIONS LABEL A TT ACHED TO THE HEA TER.

THESE INSTRUCTIONS ARE REPEATED IN THE LIGHTING AND OPERA TING LABEL ILLUSTRA TION ON P AGE 20 IN THIS MANUAL.

A minimum gas supply pressure of 5.0" (1.25 kPa) W.C. (4.5" or 1.12 kPa) on BTH 150 and 199) for natural gas (11.0" or 2.74 kPa W.C. for L.P. 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.

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, (Figure15).

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 or counterclockwise on BTH 120 and 250 (3.5" or .87 kPa on BTH 150 and 199) for natural gas (10.0" or 2.5 kPa W.C. for L.P. Gas) Water Column.

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 AL TITUDE 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

X H = Btuh

Should it be necessary to adjust the gas pressure to the burner, to obtain the full input rate, the steps below should be followed:

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-199 heater) T = 18.9 seconds

H = 1050 Btu/ft. BTUH = ?

For high altitude installations, compare result to the derated input required for the elevation at the installation location.

c. Remove the pressure regulator cover screw (Figure 16) and adjust

the pressure by turning the adjusting screw with a small

screwdriver. Do not exceed 4.0" (1 kPa) on BTH 120 and 250

(3.5" (.87 kPa) on BTH 150 and 199) 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.

to decrease gas pressure to obtain 4.0" (1 kPa)

3600

X 1050 = 199,900 Btuh (59 Kw)

18.9

to increase

Page 19

FOR YOUR SAFETY READ BEFORE OPERA TING

WARNING:

explosion may result causing property damage, personal injury or loss of life.

If you do not follow these instructions exactly, a fire or

Page 20

UNDER NO CIRCUMSTANCES SHOULD THE INPUT EXCEED THE RA TE SHOWN ON THE HEATER RA TING PLA TE. OVERFIRING COULD RESUL T IN DAMAGE OR SOOTING OF THE HEATER.

WARNING

CA THODIC PROTECTION

CAUTION

HYDROGEN GAS CAN BE PRODUCED IN A HOT W A TER SYSTEM SERVED BY THIS HEA TER 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 OPERA TE HEA TER

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

HIGH ALTITUDE INST ALLATIONS

WARNING

BTH HEATERS ARE CERTIFIED FOR USE WITHOUT MODIFICA TION FOR ALTITUDES UP TO 6500 FEET . INSTALLATIONS ABOVE 6500 FEET MA Y REQUIRE REPLACEMENT OF THE BURNER ORIFICE. CALL THE TECHNICAL CENTER @ (800) 527-1953 FOR REQUIREMENTS.

Some gas utility companies derate their gas for altitude, making it unneccessary to install high altitude orifices. Call the local gas or utlity 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 V APORS AND LIQUIDS. (SEE WARNING ON P AGE 5, LOCA TING THE HEA TER).

3. DAMAGE

4. FIRING WITHOUT WATER

5. SOOTING

NEVER OPERA TE THE HEATER WITHOUT FIRST BEING CERT AIN IT IS FILLED WITH WA TER AND A TEMPERA TURE AND PRESSURE RELIEF VAL VE IS INST ALLED IN THE RELIEF V AL VE OPENING OF THE HEA TER.

SHOULD OVERHEATING OCCUR OR THE GAS SUPPL Y F AIL T O SHUT OFF, TURN OFF THE MANUAL GAS CONTROL VALVE TO THE APPLIANCE.

GENERAL INFORMATION

POWER BURNER

The initial start-up procedure of the unit is provided on page 18. 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).

TABLE 4

GAS SUPPL Y SPECIFICA TIONS

Max. Gas Supply Pressure W.C. 12.0 12.0 14.0

Nominal Gas Supply Press. W.C 7.0 7.0 11.0

Minimal Gas Supply Press. W.C. 5.0 4.5 11.0

Manifold Press. W.C. 4.0 3.5 10.0

BTH 120 BTH 150 BTH 120,

& 250 & 199 150 & 199

Natural Gas Natural Gas L.P . Gas

(3 kPa) (3 kPa) (3.45 kPa)

(1.74 kPa) (1.74 kPa) (2.74 kPa)

(1.25 kPa) (1.12 kPa) (2.74 kPa)

(1 kPa) (872 kPa) (2.5 kPa)

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 recommended maintenance. Unit inspection and adjustment should be performed by a competent technician.

COMPONENT OPERA TION INTERVAL REQUIRED

T ank Sediment Monthly Flushing

Removal

T ank Lime Scale Semi UN-LIME

Removal Annually Delimer

Anode Inspect Semi Replace as

Rods Annually Required

Relief Valve Inspect Semi

Annually

SAE No. 20

Circulating Oiling Four Months non-detergent

Pump (1) motor oil

Clean Inlet

Blower Screen and As Required Soft Brush

Blower Wheel

Vent System Inspect Every 3 Joints should

Months be sealed

(1) If furnished with oiling provision.

Page 21

FLUSHING

1. Turn off the heater electrical disconnect switch.

2. Open the drain valve and allow water to flow until it runs clean.

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.

FIGURE 25

To dissolve and remove the more stubborn mineral deposits, A.O. Smith UN•LIME® Professional Delimer should be used.

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.

SEDIMENT REMOV AL

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.

LIME SCALE REMOV AL

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.

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.

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 25. The heater must be drained, see DRAINING, before removing cleanout cover on tank.

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, 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 25. 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.

6. Install cleanout plate. Be sure to draw plate up tight by tightening screws securely.

7. Close drain valve, open water inlet line and turn on the power burner electrical disconnect switch.

8. Check for water leakage.

9. Replace outer jacket cover plate.

ANODE INSPECTION AND REPLACEMENT

This water heater is equipped with multiple sacrificial anodes. Anodes protect the glass-lined tank from corrosion by sacrificing themselves through electrolysis. When the anode material is consumed, there is no more protection and corrosion of the tank accelerates

Inspection of the anode every 6 to 12 months allows you to identify a spent anode and replace it. Replace the anode when its diameter is 3/8" (1cm) of an inch, or annually which ever is first. Aggressive, very hot and softened water causes rapid consumption of the anode requiring frequent inspections. Anodes are available from your distributor or A.O. Smith.

Page 22

To inspect or replace an anode:

The anodes on this heater are easily accessible from the top of the heater making replacement simple and quick.

1. Turn the heater off per the lighting instructions. Connect a hose to the drain valve . Locate the hose's discharge in an area where hot water will not cause any damage or injury.

2. Open the drain valve to flush any sediment out of the bottom of the heater.

CAUTION

BEFORE MANUALLY OPERATING THE VALVE, MAKE SURE THAT A DRAIN LINE HAS BEEN ATTACHED TO THE VA LVE TO DIRECT THE DISCHARGE TO AN OPEN DRAIN. F AILURE TO T AKE THIS PRECAUTION COULD MEAN CONTACT WITH EXTREMEL Y HOT WA TER P ASSING OUT THE VAL VE DURING THIS CHECKING OPERA TION.

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.

3. Shut off the cold water supply. Make sure all hot water fixtures and circulating pumps are turned off.

4. Wait for water flow from the hose to stop. Remove the anode using a socket of the appropriate size Sometimes a pry bar will be required to loosen the anode plug . Do not use an impact wrench.

5. Inspect and replace the anode as required. Use a pipe tape or sealant when reinstalling the anode.

6. Close the drain valve . Open a hot water fixture to allow air to escape. Open the cold water supply to heater and allow the tank to fill. Follow the lighting instructions.

7. Check your anode and drain valve for leaks.

DRAIN V AL VE AND ACCESS P ANELS

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, figure 25.

RELIEF VAL VE

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.

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.

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.

Contact your water supplier or local plumbing inspector on how to control this situation.

Two common corrections are listed in the Checklist and Service Information which appears later in this manual.

ABOVE ALL, DO NOT PLUG THE TEMPERA TURE AND PRESSURE RELIEF VALVE. THIS IS NOT A SOLUTION AND CAN CREATE A HAZARDOUS SITUATION.

CIRCULA TING PUMP

The water heating system may include a circulating pump. Where used, it should be lubricated as directed by the circulator manufacturer.

VENT SYSTEM

Examine the vent system every 3 months. Points of inspection are as follows:

1. Check for obstructions and/or deterioration of vent piping and vent hood. Replace immediately where needed.

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.

Page 23

INST ALLA TION DIAGRAMS

ONE TEMPERA TURE - ONE HEA TER VERTICAL STORAGE T ANK FORCED CIRCULA TION

WITH OR WITHOUT BUILDING RECIRCULATION

CAUTION: IF BUILDING COLD WATER SUPPLY HAS A BACKFLOW PREVENTER, CHECK VAL VE OR WA TER 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 TEMPERA TURE - ONE HEA TER HORIZONT AL STORAGE T ANK

FORCED CIRCULATION WITH OR WITHOUT BUILDING RECIRCULA TION

DANGER

TEMPERATURE SETTING SHOULD NOT EXCEED SAFE TEMPERATURE AT FIXTURES. SEE WATER TEMPERATURE CONTROL W ARNING ON P AGE 4. IF HIGHER PREHEAT TEMPERATURES ARE NECESSARY TO OBTAIN ADEQUATE BOOSTER OUTPUT, ADD AN ANTI-SCALD VALV E FOR HOT WATER SUPPLIED TO FIXTURES.

*PIPE TO OPEN DRAIN

INSTALL IN ACCORDANCE WITH LOCAL CODES

Page 24

TWO TEMPERA TURE - ONE HEATER HIGH TEMPERA TURE

WITH OR WITHOUT BUILDING RECIRCULA TION

DANGER

TEMPERATURE SETTING SHOULD NOT EXCEED SAFE TEMPERATURE A T FIXTURES. SEE WA TER TEMPERA TURE CONTROL WARNING ON P AGE 4. 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 BACK-FLOW PREVENTER, CHECK VALVE OR WATER METER WITH CHECK VA LVE PROVISIONS FOR THERMAL EXPANSION OF WATER IN THE HOT WATER SYSTEM MUST BE PROVIDED.

PIPE RELIEF VALVE TO OPEN DRAIN.

NOTE: IF TEMPERED WATER IS RECIRCULA TED, RETURN LINE SHOULD BE CONNECTED AT POINT “A”.

INSTALL IN ACCORDANCE WITH LOCAL CODES.

Page 25

TWO TEMPERATURE - TWO HEA TERS HIGH TEMPERA TURE

WITH OR WITHOUT BUILDING RECIRCULA TION

TWO TEMPERATURE - THREE HEA TERS (TWO PRE-HEA TERS/ONE BOOSTER HEA TER)

WITH OR WITHOUT BUILDING RECIRCULA TION

MUST BE IDENTICAL HEA TERS

FOR MULTIPLE HEATER INSTALLATION SEE MANIFOLD KIT SPECIFICATIONS, P AGE 28.

CAUTION: IF BUILDING COLD WATER SUPPLY HAS A BACK-FLOW PREVENTER, CHECK V ALVE OR WATER METER WITH CHECK VALVE PROVISIONS FOR THERMAL EXP ANSION OF WA TER IN THE HOT WATER SYSTEM MUST BE PROVIDED.

DANGER

TEMPERATURE SETTING SHOULD NOT EXCEED SAFE TEMPERA TURE AT FIXTURES. SEE W ATER TEMPERA TURE CONTROL W ARNING ON P AGE

4. IF HIGHER PREHEAT TEMPERA TURES ARE NECESSARY T O OBT AIN ADEQUATE BOOSTER OUTPUT, ADD AN ANTI-SCALD V AL VE FOR HOT WA TER SUPPLIED TO FIXTURES.

Page 26

TWO TEMPERA TURE - TWO HEATERS (ONE PRE-HEA TER/ONE BOOSTER HEA TER)

WITH OR WITHOUT BUILDING RECIRCULA TION

DANGER

TEMPERATURE SETTING SHOULD NOT EXCEED SAFE TEMPERA TURE AT FIXTURES. SEE W ATER TEMPERA TURE CONTROL W ARNING ON P AGE

4. IF HIGHER PREHEAT TEMPERA TURES ARE NECESSARY T O OBT AIN ADEQUATE BOOSTER OUTPUT, ADD AN ANTI-SCALD V AL VE FOR HOT WA TER SUPPLIED TO FIXTURES

* PIPE RELIEF VALVE T O OPEN DRAIN ** 140°F (60°C)TO 150°F (66°C) SHOULD BE MAXIMUM WATER

TEMPERATURE MAINT AINED IN THE PRE-HEA TERS. 120°F (49°C) SHOULD BE THE MINIMUM TEMPERA TURE OF WA TER

IN THE PRE- HEA TERS. CONNECT CIRCULA TING LINE FROM FIXTURES, IF USED, TO COLD

WA TER SUPPLY LINE OF PRE-HEA TER. CONNECT CIRCULA TING LINE OF 180°F (82°C) OR BOOSTED WA TER,

IF USED, TO INLET W ATER LINE TO BOOSTER. INSTALL IN ACCORDANCE WITH LOCAL CODES.

Page 27

TWO TEMPERA TURE - ONE HEATER HIGH TEMPERATURE

WITH RECIRCULATION OF SANITIZING LOOP

DANGER

TEMPERATURE SETTING SHOULD NOT EXCEED SAFE TEMPERA TURE AT FIXTURES. SEE W ATER TEMPERA TURE CONTROL W ARNING ON PAGE

5. IF HIGHER PREHEAT TEMPERA TURES ARE NECESSARY T O OBT AIN ADEQUATE BOOSTER OUTPUT, ADD AN ANTI-SCALD V AL VE FOR HOT WA TER SUPPLIED TO FIXTURES.

CAUTION: IF BUILDING COLD WATER SUPPLY HAS A BACK-FLOW PREVENTER, CHECK VALVE OR WATER METER WITH CHECK V ALVE PROVISIONS FOR THERMAL EXP ANSION OF WA TER IN THE HOT WA TER SYSTEM MUST BE PROVIDED.

*PIPE RELIEF VAL VE TO OPEN DRAIN

INSTALL IN ACCORDANCE WITH LOCAL CODES

NOTE 1: TOGGLE SWITCH CONTROLS 180°F (82°C) WA TER CIRCULATION. INST ALL ON OR CLOSE TO DISHW ASHER. TOGGLE SWITCH MUST BE CLOSED (ON) DURING THE RINSE OPERA TION AND OPEN (OFF) WHEN DISHWASHER IS NOT OPERA TING OR WHEN ON LONG ST ANDBY .

NOTE 2: INSTALL LINE TEMPERATURE CONTROL IN AN UNINSULA TED TEE BEYOND THE DISHWASHER TAKEOFF IN THE SANITIZING LOOP. CONTROL SHOULD BE SET A T 185°F (85°C).

NOTE 3: ADJUST PLUG COCK SO THE SANITIZING LOOP FLOW RATE DOES NOT CAUSE UNNECESSARY TURBULENCE IN THE T ANK.

NOTE 4: IF TEMPERED WA TER IS RECIRCULATED, RETURN LINE SHOULD BE CONNECTED A T POINT A.

Page 28

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.

Page 29

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.

BE SURE TO TURN OFF THE ELECTRICITY WHENEVER POSSIBLE OR APPROPRIATE WHILE CHECKING EQUIPMENT .

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.

WA TER 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.

FAILURE TO FOLLOW THESE INSTRUCTIONS CAN RESUL T IN SERIOUS

WARNING

PERSONAL INJURY OR DEA TH.

CAUTION: LABEL ALL WIRES PRIOR TO DISCONNECTION WHEN SERVICING CONTROLS. WIRING ERRORS CAN CAUSE IMPROPER AND DANGEROUS OPERATION.

VERIFY PROPER OPERA TION AFTER SER VICING .

BURNER OPERA TIONAL PROBLEMS

1. Refer to TROUBLESHOOTING .

NOT ENOUGH OR NO HOT WATER

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.

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.

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.

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.

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.

9. Burner fan wheel may be dirty.

• Clean fan wheel with a stiff brush.

10. Condensate hose may be blocked where it connects to the exhaust elbow.

• Verify the condensate drains from the unit without restriction.

3. If the outlet of the relief valve is leaking it may represent:

• Excessive water pressure.

• Excessive water temperature.

• Faulty relief valve.

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 damage d. Refer to MAINTENANCERELIEF VALVE section in this manual.

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 also.

TROUBLE-SHOOTING

1. Verify that the allowable vent length has not been exceeded and that the blower inlet screen has been removed if direct venting.

2. Verify that the condensation, which WILL be present in the heater and exhaust vent, will drain.

3. Check supply wire polarity - hot to hot and neutral to neutral and no "stray" current in neutral.

4. Heater is properly grounded.

Checking these four (4) items first will often result in a timely solution to the service call.

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 MICROAMMETER, DO NOT A TTEMPT TO TROUBLESHOOT OR REP AIR A.O. SMITH EQUIPMENT .

ALTERING THE CONTROLLER AND/OR CONTROLLER WIRING IN ANY WAY COULD RESULT IN INTERNAL DAMAGE TO THE MODULE CIRCUITS, POSSIBLY AL TERING THE IGNITION SEQUENCE ALLOWING GAS V ALVES TO OPEN BEFORE THE HOT SURF ACE IGNITER IS UP T O IGNITION TEMPERATURE.

NOTE: ANY BYP ASS OR ALTERATION OF THE UNITS SAFETIES WILL RESULT IN VOIDING THE APPLIANCE W ARRANTY.

Before performing any troubleshooting familiarize yourself with the particular appliance.

WATER IS TOO HOT

1. Refer to WATER TEMPERATURE CONTROL.

WA TER HEA TER MAKES SOUNDS

1. Sediment or lime scale accumulations cause rumbling and pounding noises when the heater is operating.

• The sounds are normal, however, the tank bottom should be cleaned. Refer to MAINTENANCE for details.

Refer to the SEQUENCE OF OPERATION and the connection diagram located on page 15 before continuing.

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.

CAUTION

THE WATER HEATER IS POLARITY SENSITIVE. BEFORE APPLYING ELECTRICITY TO THIS HEATER BE CERTAIN THAT SUPPLY HEATED WIRE TO GROUND CHECK INDICA TES ZERO VOL TAGE.

Page 30

MOTOR WILL NOT RUN

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 12" Natural Gas (3 kPa) and 14.0" L.P. Gas (3.45 kPa) W . C . maximum. 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, 5.0" (1.25 kPa) W.C. for BTH 120 & 250 or 4.5" (1.1 kPa) W.C. for BTH 150 & 199 or; for L.P. Gas, 11.0" (2.74 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, 4.0" (1 kPa) W.C. for BTH 120 & 250 or 3.5" (.9 kPa) W.C. for BTH 150 & 199 or; for L.P. Gas,

10.0" (2.5 kPa) W.C. If the manifold pressure is not correct then adjust accordingly. See ADJUSTMENT PROCEDURE in OPERATING INSTRUCTIONS selection, page 18, 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.

MOTOR RUNS, BURNER LIGHTS MOMENT ARIL Y ,

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 14.0" (3.5 kPa) W.C. or lower than

the minimal gas supply pressure, as shown in Table 4: that is, for Natural Gas, 5.0" (1.25 kPa) W.C. for BTH 120 & 250 or 4.5" (1.1 kPa) W.C. for BTH 150 & 199 or; for L.P. Gas, 11.0" (2.74 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, 4.0" (1 kPa) W.C. for BTH 120 & 250 or

3.5" (.9 kPa) W.C. for BTH 150 & 199 or; for L.P. Gas, 10.0" (2.5 kPa) W.C. If the manifold pressure is not correct then adjust accordingly. See ADJUSTMENT PROCEDURE in OPERATING INSTRUCTIONS section, p age 18, for the manifold pressure adjustment procedure.

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 12" Natural Gas (3 kPa), 14.0" L.P. Gas (3.45 kPa) W.C. and the manifold pressure as listed in Table 4: that is, for Natural Gas, 4.0" (1 kPa) W.C. for BTH 120 & 250 or 3.5" (.9 kPa) W.C. for BTH 150 & 199 or; for L.P. Gas, 10.0" (2.5 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 OPERA TION

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 P ARTS” segment below.

GAS FAILS T O SHUT OFF

Check for defective gas valve or thermostat. If operation is incorrect, replace.

REPLACEMENT P ARTS

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, 5621 W. 115th Street, Alsip, IL 60803, 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.

Page 31

Model BTH Limited Warranty

A. O. Smith Corporation, the warrantor, extends the following LIMITED WARRANTY to the owner of this water heater.

1. 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.

2. ALL OTHER P ARTS 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.

3. 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 AGA/CGA and approved by the American Society of Mechanical Engineers, must have been installed.

a. This warranty shall apply only when the heater is used:

(1 ) used at temperatures not exceeding the maximum setting of its thermostat; (2 ) used at water pressure not exceeding the working pressure shown on the heater; (3) when operated free of the damaging effects of uncontrolled water hammer; (4 ) filled with potable water, free to circulate at all times and with the tank free of damaging water sediment or scale deposits; (5 ) used in a non-corrosive and non-contaminated atmosphere; (6 ) used with factory approved anode(s) installed; (7) in its original installation location; (8 ) in the United States, its territories or possessions, and Canada; (9 ) sized in accordance with proper sizing techniques for commercial and/or residential water heaters; (10) bearing a rating plate which has not been altered, defaced or removed, except as required by the warrantor; (11) operated with properly installed dirt leg; (12) fired with the fuel for which it was factory built; (13) fired at the factory rated input; (14) operated with the inner and outer combustion chamber doors in place.

b. Any accident to the water heater, 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.

4. 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.

5. LIMIT A TIONS ON IMPLIED W ARRANTIES 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.

6. CLAIM PROCEDURE Any claim under the warranty should be initiated with the dealer who sold the boiler, or with any other dealer handling the warrantor’s products. If this is not practicable, the owner should contact:

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.

7. DISCLAIMERS NO OTHER EXPRESS WARRANTY HAS BEEN OR WILL BE MADE IN BEHALF OF THE WARRANTOR WITH RESPECT TO THE MERCHANT ABILITY OF SHEA TER OR THE INSTALLA TION, OPERA TION, REPAIR OR REPLACEMENT OF THE BOILER. THE W ARRANTOR SHALL NOT BE RESPONSIBLE FOR WA TER DAMAGE, LOSS OF USE OF THE UNIT , INCONVENIENCE, LOSS OR DAMAGE TO PERSONAL PROPERTY OR OTHER CONSEQUENTIAL DAMAGE. THE W ARRANTOR SHALL NOT BE LIABLE BY VIRTUE OF THIS W ARRANTY OR OTHER WISE FOR DAMAGE T O ANY PERSONS OR PROPERTY , WHETHER DIRECT OR INDIRECT, AND WHETHER ARISING IN CONTRACT OR TOR T . 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 Dealer’s Address__________________________________________________City and State___________________________________________Zip Code

__________________________________________________________________________Phone No.___________________________________________________

U.S. Customers Canadian Customers A. O. Smith Corporation A. O. Smith Enterprises Ltd. 5621 W. 115th Street P. O. Box, 310 - 768 Erie Street Alsip, IL 60803 Stratford, Ontario N5A 6T3 Telephone: (800) 323-2636 Telephone: (800) 265-8520

_________________

FILL IN WARRANTY AND KEEP FOR FUTURE REFERENCE.

Page 32

A.O. SMITH WATER PRODUCTS COMPANY

5621 W. 115TH STREET • ALSIP, ILLINOIS 60803

PHONE: 1-800-433-2545 • FAX: 1-800-433-2515

www.hotwater.com • E-MAIL: parts@hotwater.com

A.O. Smith BTH 120-250A User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual