A.O. Smith 500A User Manual

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CYCLONE Xi®

Model BTH 300A, 400A, 500A

COMMERCIAL GAS WATER HEATER

GAS-FIRED POWER BURNER

FOR DOMESTIC HOT WATER

• INSTALLATION • OPERATION • SERVICE • MAINTENANCE • LIMITED WARRANTY

WARNING: If the information in these

instructions is not followed exactly, a re

or explosion may result causing property damage, personal injury or death.

– Do not store or use gasoline or other

ammable 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 no t us e any ph one in you r

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 re department.

– Installation an d ser vic e must be performed by a qualified installer, service agency or the gas supplier.

Thank you for buying this energy efcient water heater from A.O. Smith Water Products Company. We appreciate your condence in our products.

CAUTION

TEXT PRINTED OR OUTLINED IN RED CONTAINS INFORMATION RELATIVE TO YOUR SAFETY. PLEASE READ THOROUGHLY BEFORE INSTALLING AND USING

THIS APPLIANCE.

PLACE THESE INSTRUCTIONS ADJACENT TO HEATER AND NOTIFY OWNER TO KEEP FOR FUTURE REFERENCE.

PRINTED 0307 197373-003

www.hotwater.com

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ROUGH-IN-DIMENSIONS

GAS VALVE PIPING

BTH-300 1 1/4" NPT BTH-400 1 1/4" NPT BTH-500 1 1/2" NPT

TABLE 1 RECOVERY CAPACITIES.

TYPE OF INPUT Approx. F° 20F° 30F° 40F° 50F° 60F° 70F° 80F° 90F° 100F° 110° 120F° 130F° 140F° MODEL GAS BTUH KW Capacity C° 11C° 17C° 22C° 28C° 33C° 39C° 44C° 50C° 56C° 61C° 67C° 72C° 78C°

300,000 130 US Gals. GPH 1746 1164 873 699 582 499 436 388 349 318 291 269 250

BTH-300

88 492 Litres LPH 6610 4406 3304 2644 2203 1888 1652 1469 1322 1201 1102 1017 945 300,000 130 US Gals. GPH 1746 1164 873 699 582 499 436 388 349 318 291 269 250

BTH-300

88 492 Litres LPH 6610 4406 3304 2644 2203 1888 1652 1469 1322 1201 1102 1017 945

399,900 130 US Gals. GPH 2328 1552 1164 931 776 665 582 517 466 423 388 359 332

BTH-400

117 492 Litres LPH 8813 5875 4406 3525 2938 2518 2203 1958 1763 1602 1469 1356 1259

399,900 130 US Gals. GPH 2328 1552 1164 931 776 665 582 517 466 423 388 359 332

BTH-400

117 492 Litres LPH 8813 5875 4406 3525 2938 2518 2203 1958 1763 1602 1469 1356 1259 499,900 130 US Gals. GPH 2878 1919 1439 1151 959 822 720 640 576 523 480 443 411

BTH-500

146 492 Litres LPH 10894 7263 5447 4358 3631 3113 2724 2421 2179 1981 1816 1676 1556 499,900 130 US Gals. GPH 2878 1919 1439 1151 959 822 720 640 576 523 480 443 411

BTH-500

146 492 Litres LPH 10894 7263 5447 4358 3631 3113 2724 2421 2179 1981 1816 1676 1556

Recovery capacities are based on heater performance at 96% thermal efciency for BTH 300A, 400A, and 95% thermal efciency for BTH 500A.

NATURAL

PROPANE

NATURAL

PROPANE

NATURAL

PROPANE

U.S. Gallons/Hr and Litres/Hr at TEMPERATURE RISE INDICATED

FOREWORD

These designs comply with the current edition of the American Nati o n al S t a nd a r d f o r Gas Wat e r H ea t e rs , Volu m e II I , ANSI Z21.10.3 / CSA 4.3 as an automatic circulating tank water heater, and automatic storage water heaters.

Detailed installation diagrams are found in this manual. These diagrams will serve to provide the installer with a reference for the materials and methods of piping necessary. It is highly essential that all water, gas piping and wiring be installed as shown on the diagrams.

Particular attention should be given to the installation of thermometers at the locations indicated on the diagrams as these are necessary for checking the proper functioning of the heater.

In addition to these instructions, the equipment shall be installed in accordance with those installation regulations in force in the local area where the installation is to be made. These shall be carefully followed in all cases. Authorities having jurisdiction should be consulted before installations are made.

In the absence of local codes, the installation must comply wi th the cu rrent edition s of the Na tiona l Fuel Ga s Code, AN S I Z223.1/NFPA 54 an d th e National El e c t rical Code, NFPA 70 or CAN/CSA-B149.1, the Natural Gas and Propane Installation Code and CSA C22.1, the Canadian Electrical Code. All documents are available from the Canadian Standards Association, 8501 East Pleasant Valley Road, Cleveland, OH 44131. NFPA documents are also available from the National Fire Protection Association, 1 Batterymarch Park, Quincy, MA 02269.

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TABLE OF CONTENTS

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

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

FEATURES ................................................................................................ 3

Water Temperature Control ................................................................3-5

Water Temperature Setpoint Adjustment Procedure ............................. 5

High Limit Switch (E.C.O.) .................................................................... 5

Dishwashing Machine Requirement ...................................................... 5

Circulating Pump ...................................................................................6

INSTALLATION INSTRUCTIONS .............................................................6

Required Ability ..................................................................................... 6

Insulation Blankets ................................................................................ 6

Locating The Heater .............................................................................. 6

Clearances ............................................................................................ 7

Hard Water ............................................................................................7

Air Requirements .................................................................................. 7

Mechanical Exhausting of Room Air .....................................................7

Unconned Space .................................................................................7

Conned Space ..................................................................................... 7

Chemical Vapor Corrosion .................................................................... 7

Installation Requirements for the

Commonwealth of Massachusetts ........................................................8

VENTING ..............................................................................................8-11

Vent Pipe Termination .........................................................................11

Direct Venting ...................................................................................... 11

Direct Vent Terminal Installation ..................................................... 11-12

Installation Sequence ..........................................................................12

Vertical Vent Terminal Installation ....................................................... 12

Installation Sequence .....................................................................12-13

Installation of Vent System .................................................................. 13

Vent Pipe Preparation ......................................................................... 14

CONTROLS AND SWITCHES ................................................................ 14

Blower Prover Switch .......................................................................... 14

Blocked Outlet Prover Switch .............................................................. 14

Blocked Inlet Prover Switch ................................................................ 14

Low Gas Pressure Switch ................................................................... 14

On/Off Switch .................................................................................14-15

Hot Surface Igniter ..............................................................................15

GAS PIPING ............................................................................................ 15

Connection of Gas Pipe .................................................................15-16

Purging ................................................................................................16

Gas Meter Size - City Gases Only ......................................................16

Gas Valves ..........................................................................................16

SYSTEM CONNECTIONS ...................................................................... 16

Thermometers .....................................................................................16

Relief Valve ......................................................................................... 16

Water Line Connections ......................................................................16

Closed System ...............................................................................16-17

Water (Potable) Heating & Space Heating .......................................... 17

Heater Wiring .................................................................................17-19

OPERATION ............................................................................................ 20

Sequence of Operation .......................................................................20

ELECTRONIC CONTROL ....................................................................... 20

Overview .............................................................................................20

Operating States ............................................................................20-21

Adjusting the Operating Set Point .......................................................

Changing the Display Units .................................................................22

Fault and Warning Conditions ........................................................22-23

Access to the Current Fault or Warning .............................................. 23

Viewing the Fault History ....................................................................

Viewing Information About the Heater .................................................24

PRIOR TO START-UP REQUIRED ABILITY ...........................................25

OPERATING INSTRUCTIONS ................................................................ 25

Adjustment Procedure (Initial Start-Up) .........................................25-26

Lighting Instructions ............................................................................26

Cathodic Protection .............................................................................27

Precautions .........................................................................................27

GENERAL INFORMATION ......................................................................27

Power Burner ......................................................................................27

High Limit ............................................................................................27

High Altitude Installations ....................................................................27

MAINTENANCE ......................................................................................27

General ............................................................................................... 27

Maintenance Schedule ........................................................................ 27

Flushing ............................................................................................... 28

Draining ...............................................................................................28

Sediment Removal ..............................................................................28

Lime Scale Removal ......................................................................28-29

Powered Anode System ...................................................................... 29

Drain Valve and Access Panels .......................................................... 29

Relief Valve ......................................................................................... 29

Vent System ........................................................................................29

INSTALLATION DIAGRAMS ..............................................................30-34

Multiple Unit Installations .................................................................... 35

CHECKLIST AND SERVICE INFORMATION ......................................... 36

Burner Operational Problems .............................................................. 36

Not Enough or No Hot Water ..............................................................36

Water Is Too Hot ..................................................................................36

Water Heater Makes Sounds .............................................................. 36

Water Leakage is Suspected ...................................................................36

TROUBLESHOOTING .......................................................................36-38

REPLACEMENT PARTS .........................................................................38

LIMITED WARRANTY ............................................................................. 39

FEATURES

IMPORTANT

IT IS REQUIRED THAT A QUALIFIED SERVICE TECHNICIAN

PERFORM THE INITIAL FIRING OF THE HEATER. AT THIS TIME

THE USER SHOULD NOT HESITATE TO ASK THE TECHNICIAN ANY QUESTIONS WHICH HE MAY HAVE IN REGARD TO THE OPERATION AND MAINTENANCE OF THE UNIT.

A CHECKLIST AND SERVICE INFORMATION section are included at the rear of this manual. By using this checklist the user may be able to make minor operational adjustments and save himself unnecessary service calls. However, the user should not attempt repairs which are not listed in this section.

WATER TEMPERATURE CONTROL

DANGER

THIS WATER HEATER IS EQUIPPED WITH AN ADJUSTABLE THERMOSTAT TO CONTROL WATER TEMPERATURE. HOT WA TER TEM P ERATUR ES REQU I RED FOR AUTOMA TIC DISHW ASHER AND LAUND RY USE CAN CAUSE SCALD BURNS RESULTING IN SERIOUS PERSONAL INJURY AND/OR DEATH. THE TEMPERATURE AT WHICH INJURY OCCURS VARIES WITH THE PERSON’S AGE AND TIME OF EXPOSURE. THE SLOWER RESPONSE TIME OF CHILDREN, AGED OR DISABLED PERSONS INCREASES THE HAZARDS TO THEM. NEVER ALLOW SMALL CHILDREN TO USE A HOT WATER TAP, OR TO DRAW THEIR OWN BATH WATER. NEVER LEAVE A CHILD OR DISABLED PERSON UNATTENDED IN A BATHTUB OR SHOWER.

THE WATER HEATER SHOULD BE LOCATED IN AN AREA WHERE THE GENERAL PUBLIC DOES NOT HAVE ACCESS TO

SET TEMPERATURES.

The water temperature is controlled using the Temperature Control Up/Dn 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.

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“AT A GLANCE” BTH 300/400/500

QUICK INSTALLATION TIPS

Horizontal Sidewall Venting Vertical Rooftop Venting

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The temperature may be adjusted from 80°F/27°C to 180°F/82°C. The temperature was adjusted to 120°F/49°C before the heater was shipped from the factory. It is recommended that lower water temperatures be used to avoid the risk of scalding. It is further recommended, in all cases, that the water temperature be set for the lowest temperature which satises your hot water needs. This will also provide the most energy efcient operation of the water heater and minimize scale formation.

WATER TEMPERATURE SETPOINT ADJUSTMENT

PROCEDURE

CAUTION

THE TEMPERATURE OF THE WATER AT THE TANK OUTLET MAY NOT CORRESPOND TO THE TEMPERATURE SETPOINT PROGRAMMED IN THE CONTROLLER. THE USER CAN EASILY CHANGE THE TEMPERATURE SETPOINT AT ANY TIME BY USING THE FOLLOWING PROCEDURE. IN ALL CASES, INPUT POWER MUST BE APPLIED TO THE CONTROLLER TO PERFORM ANY

PROGRAMMING OPERATIONS.

The Operating Set Point of this water heater determines the regulated

temperature for the water in the tank. This parameter is adjusted in the Temperature menu. Items in this menu allow you to monitor different temperature readings in the tank along with adjusting the Operating Set Point and Differential. To change the current programmed temperature setpoint value, see OPERATION section for details.

Figure 1 shows the approximate time-to-burn relationship for normal adult skin. Short repeated heating cycles caused by small hot water uses can cause temperatures at the point of use to exceed the thermostat setting by up to 20°F (11C°). If you experience this type of use, you should consider using lower temperature settings to reduce scald hazards.

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.

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 ow should the water temperature reach approximately 202°F/94°C. Should the high limit switch activate, the water temperature must drop below 140°F/60°C before the controller can be reset. The following is a possible reason for high limit switch operation.

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.

• 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 dish washing machines meeting the National Sanitation Foundation requirements are designed to operate with water ow 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 ow 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 ow by means of the plug cock in the circulating line. (See installation diagrams.)

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CIRCULATING PUMP

A circulating pump is used when a system requires a circulating loop or there is a storage tank used in conjunction with the heater. Refer to the piping diagrams at rear of manual for electrical hookup information and install in accordance with the current edition of the National Electrical Code, NFPA 70 or the Canadian Electrical Code, CSA C22.1.

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

Although circulators are oiled and operated by the manufacturer some circulators must be oiled again before operated. Please refer to manufacturer's instructions.

INSTALLATION INSTRUCTIONS

REQUIRED ABILITY

IN S TALLATI O N OR SERV I CE OF TH IS WATER HEATE R REQUIRES ABILITY EQUIVALENT TO THAT OF A LICENSED TRADESMAN IN THE FIELD INVOLVED. PLUMBING, AIR SUPPLY, VENTING, GAS SUPPLY AND ELECTRICAL WORK ARE REQUIRED.

INSULATION BLANKETS

Insulation blankets available to the general public for external use on gas water heaters are not approved for use on your A.O. Smith water heater. The purpose of an insulation blanket is to reduce the standby heat loss encountered with storage tank water heaters. Your A.O. Smith water heater meets or exceeds the ASHRAE/IES

90.1-1999 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 re, asphyxiation, serious personal injury or death.

• Do not apply insulation to the top, or the upper 15" (38 cm) of the water heater, as this will interfere with safe operation.

• Do not cover the temperature & pressure relief valve.

• Do not cover the instruction manual. Keep it on the side of the

water heater or nearby for future reference.

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

DO NOT LOCATE THE HEATER WHERE NOISE FROM THE EX HAUS T OR INTAKE WILL BE OBJEC TIONA BLE. THIS IN C LUDES LOC ATIONS CL O SE TO OR ACROSS FR O M WINDOWS AND DOORS. AVOID ANCHORING THE VENT AND INTAKE PIPES DIRECTLY TO FRAMED WALLS, FLOORS OF CEILINGS UNLESS RUBBER ISO LATION PIPE HANGERS

ARE USED. THIS PREVENTS ANY VIBRATIONS FROM BEING TRANSMITTED INTO THE LIVING SPACES.

WARNING

FLAMMABLE ITEMS, PRESSURIZED CONTAINERS OR ANY OTHER POTENTIAL FIRE HAZARDOUS ARTIC LES MUST NEVER BE PLACED ON OR ADJACENT TO THE HEATER. OPEN CONTAINERS OF FLAMMABLE MATERIAL SHOULD NOT BE STORED OR USED IN THE SAME ROOM WITH THE HEATER.

When installing the heater, consideration must be given to proper location. Location selected should be as close to the intake and exhaust term ina tion points as practic abl e, with adequate air supply and as centralized with the piping system as possible.

THE HEATER MUST NOT BE LOCATED IN AN AREA WHERE IT WILL BE SUBJECT TO FREEZING.

LOCATE IT NEAR A FLOOR DRAIN. THE HEATER SHOULD BE LOCATED IN AN AREA WHERE LEAKAGE FROM THE HEATER OR CONNECTIONS WILL NOT RESULT IN DAMAGE TO THE ADJACENT AREA OR TO LOWER FLOORS OF THE STRUCTURE.

When such locations cannot be avoided, it is recommended that a suitable drain pan, adequately drained, be installed under the appliance.

WARNING

THIS WATER HEATER IS A CONDENSING UNIT AND REQUIRES A DRAIN TO BE LOCATED IN CLOSE PROXIMITY TO ALLOW THE CONDENSATE TO DRAIN SAFELY. THE CONDENSATE DRAINS FROM THE UNIT AT THE EXHAUST ELBOW LOCATED

AT THE BOTTOM OF THE UNIT. NOTE: IT IS IMPORTANT THAT

THE CONDENSATE HOSE NOT BE ELEVATED ABOVE THE EXHAUST ELBOW (SEE FIGURE 3). THE CONDENSATE BUILDUP WILL BLOCK THE EXHAUST OUTLET, WHICH WILL CAUSE

IMPROPER OPERATION.

• Do obtain new labels from A.O. Smith for placement on the blanket

directly over the existing labels.

LOCATING THE HEATER

WARNING

THERE IS A RISK IN USING FUEL BURNING APPLIANCES SUCH AS GAS WATER HEATERS IN ROOMS, GARAGES OR OTHER AREAS WHERE GASOLINE, OTHER FLAMMABLE LIQUIDS OR ENGINE DRIVEN EQUIPMENT OR VEHICLES ARE STORED, OPERATED OR REPAIRED. FLAMMABLE VAPORS

ARE HEAVY AND TRAVEL ALONG THE FLOOR AND MAY BE

IGNITED BY THE HEATER’S IGNITER OR MAIN BURNER FLAMES CAUSING FIRE OR EXPLOSION. SOME LOCAL CODES PERMIT OPERATION OF GAS APPLIANCES IF INSTALLED 18 INCHES (46 cm) OR MORE ABOVE THE FLOOR. THIS MAY REDUCE THE RISK IF LOCATION IN SUCH AN AREA CANNOT BE AVOIDED.

FIGURE 3.

WARNING

DO NOT USE THIS APPLIANCE IF ANY PART HAS BEEN UNDER WATER. IMMEDIATELY CALL A QUALIFIED SERVICE TECHNICIAN TO INSPECT THE APPLIANCE AND TO REPLACE ANY PART OF THE CONTROL SYSTEM AND ANY GAS CONTROL WHICH HAS BEEN UNDER WATER.

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CLEARANCES

MECHANICAL EXHAUSTING OF ROOM AIR

These heaters are approved for installation on combustible ooring in an alcove when the minimum clearances from any combustion construction are followed as indicated in Figure 4.

In all installations the minimum combustible clearances from any vent piping shall be 0". Vent piping passing through a combustible wall or ceiling must be a continuous run (no joints).

A service clearance of 24" (61 cm) should be maintained from serviceable parts such as relief valves, thermostats, cleanout openings, drain valves and venting connections.

Always disconnect electrical power before servicing the unit.

*ILLUSTRATION OF MINIMUM COMBUSTIBLE CLEARANCES IN AN ALCOVE.

FIGURE 4.

HARD WATER

Where hard water conditions exist, water softening or the threshold type of water treatment is recommended. This will protect the dishwashers, coffee urns, water heaters, water piping and other equipment.

See MAINTENANCE section for details of tank cleanout procedure.

Where an exhaust fan is installed in the same room with a heater, sufcient openings for air must be provided in the walls. UNDERSIZED

OPENINGS WILL CAUSE AIR TO BE DRAWN INTO THE ROOM THROUGH THE HEATER’S VENTING SYSTEM, CAUSING POOR COMBUSTION. SOOTING MAY RESULT IN SERIOUS DAMAGE TO THE HEATER AND RISK OF FIRE OR EXPLOSION. IT CAN ALSO CREATE A RISK OF ASPHYXIATION.

UNCONFINED SPACE

In buildings of conventional frame, brick or stone construction, unconned spaces may provide adequate air for combustion and ventilation.

If the unconned 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 conned spaces in tightly constructed buildings must be followed to ensure adequate air supply.

CONFINED SPACE

When drawing combustion air from inside a conv entional ly constructed building to a conned space, such a space shall be provided with two permanent openings, ONE IN OR WITHIN 12 INCHES (31 cm) OF THE ENCLOSURE TOP AND ONE IN OR WITHIN 12 INCHES (31 cm) OF THE ENCLOSURE BOTTOM. Each opening shall have a free area of at least one square inch per 1000 Btuh (2,203mm2/kW) appliances in the enclosure, but not less than 100 square inches (645 cm²).

If the conned space is within a building of tight construction, air for combustion and ventilation must be obtained from outdoors. When directly communicating with the outdoors through vertical ducts, two permanent openings, located in the above manner, shall be provided. Each opening shall have a free area of not less than one square inch per 4000 Btuh (551mm2/kW) of the total input of all appliances in the enclosure. If horizontal ducts are used, each opening shall have a free area of not less than one square inch per 2000 Btuh (1,102mm2/kW) of the total input of all appliances in the enclosure.

AIR REQUIREMENTS

KEEP APPLIANCE AREA CLEAR AND FREE OF COMBUSTIBLE MATERIALS, GASOLINE AND OTHER FLAMMABLE VAPORS AND LIQUIDS.

DO NOT OBSTRUCT THE FLOW OF COM BUSTION AND

VENTILATING AIR.

WARNING

FO R SAFE OP ERATIO N PROVID E ADEQUATE AIR FOR COMBUSTION AND VENTILATION. AN INSUFFICIENT SUPPLY OF AIR WILL CAUSE RECIRCULATION OF COMBUSTION PRODUCTS RESULTING IN CONTAMINATION THAT MAY BE HAZARDOUS TO LIFE. SUCH A CONDITION OFTEN WILL RESULT IN A YELLOW, LUMINOUS BURNER FLAME, CAUSING CARBONING OR SOOTING OF THE COMBUSTION CHAMBER, BURNERS AND FLUE TUBE S AND CREATES A RIS K OF

ASPHYXIATION.

CHEMICAL VAPOR CORROSION

WARNING

CORROSION OF THE FLUE WAYS AND VENT SYSTEM MAY OCCUR IF A IR FOR COMBU STIO N CONTAI NS CERTAIN CHEMICAL VAPORS. SUCH CORROSION MAY RESULT IN

FAILURE AND RISK OF ASPHYXIATION.

Spray can propellants, cleaning solvents, refrigerator and air conditioning refrigerants, swimming pool chemicals, calcium and sodium chloride, waxes, and process chemicals are typical compounds which are potentially corrosive.

PRODUCTS OF THIS SORT SHOULD NOT BE STORED NEAR THE HEATER. ALSO, AIR WHICH IS BROUGHT IN CONTACT WITH THE HEATER SHOULD NOT CONTAIN ANY OF THESE CHEMICALS. IF NECESSARY, UNCONTAMINATED AIR SHOULD BE OBTAINED FROM REMOTE OR OUTSIDE SOURCES.

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INSTALLATION REQUIREMENTS FOR THE

COMMONWEALTH OF MASSACHUSETTS

For all side wall terminated, horizontally vented power vent, direct vent, and power direct vent gas fueled water heaters installed in every dwelling, building or structure used in whole or in part for residential purposes, including those owned or operated by the Commonwealth and where the side wall exhaust vent termination is less than seven (7) feet above nished grade in the area of the venting, including but not limited to decks and porches, the following requirements shall be satised:

INSTALLATION OF CARBON MONOXIDE DETECTORS

EXEMPTIONS

The following equipment is exempt from 248 CMR 5.08(2)(a)1 through 4:

1. The equipment listed in Chapter 10 entitled “Equipment Not Required To Be Vented” in the most current edition of NFPA 54 as adopted by the Board; and

2. Product Approved side wall horizontally vented gas fueled equipment installed in a room or structure separate from the dwelling, building, or structure used in whole or in part for residential purposes.

At the time of installation of the side wall horizontal vented gas fueled equipment, the installing plumber or gastter shall observe that a hard wired carbon monoxide detector with an alarm and battery back-up is installed on the floor level where the gas equipment is to be installed. In addition, the installing plumber or gastter shall observe that a battery operated or hard wired carbon monoxide detector with an alarm is installed on each additional level of the dwelling, building or structure served by the sidewall horizontal vented gas fueled equipment. It shall be the responsibility of the property owner to secure the services of qualied licensed professionals for the installation of hard wired carbon monoxide detectors.

In the event that the side wall horizontally vented gas fueled equipment is installed in a crawl space or an attic, the hard wired carbon monoxide detector with alarm and battery back-up may be installed on the next adjacent oor level.

In the event that the requirements of this subdivision can not be met at the time of completion of installation, the owner shall have a period of thirty (30) days to comply with the above requirements provided that during said thirty (30) day period, a battery operated carbon monoxide detector with an alarm shall be installed.

APPROVED CARBON MONOXIDE DETECTORS

Each carbon monoxide detector as required in accordance with the above provisions shall comply with NFPA 720 and be ANSI/UL 2034 listed and CSA certied.

SIGNAGE

A metal or plastic identication plate shall be permanently mounted to the exterior of the building at a minimum height of eight (8) feet above grade directly in line with the exhaust vent terminal for the horizontally vented gas fueled heating appliance or equipment. The sign shall read, in print size no less than one-half (1/2) inch in size, “GAS VENT DIRECTLY BELOW. KEEP CLEAR OF ALL

OBSTRUCTIONS.”

INSPECTION

The state or local gas inspector of the side wall horizontally vented gas fueled equipment shall not approve the installation unless, upon inspection, the inspector observes carbon monoxide detectors and signage installed in accordance with the provisions of 248 CMR

5.08(2)(a) 1 through 4.

MA N U FA C TURER REQ U I REMENTS - GA S EQUIPMENT VENTING SYSTEM PROVIDED

When the manufacturer of Product Approved side wall horizontally vented gas equipment provides a venting system design or venting system components with the equipment, the instructions provided by the manufacturer for installation of the equipment and the venting system shall include:

1. Detailed instructions for the installation of the venting system design or the venting system components; and

2. A complete parts list for the venting system design or venting system.

MA N U FA C TURER REQ U I REMENTS - GA S EQUIPMENT VENTING SYSTEM NOT PROVIDED

When the manufacturer of a Product Approved side wall horizontally vented gas fueled equipment does not provide the parts for venting the ue gases, but identies “special venting systems,” the following requirements shall be satised by the manufacturer:

1. The referenced “special venting system” instructions shall be included with the appliance or equipment installation instructions; and

2. The “special venting systems” shall be Product Approved by the Board, and the instructions for that system shall include a parts list and detailed installation instructions.

A copy of all installation instructions for all Product Approved side wall horizontally vented gas fueled equipment, all venting instructions, all parts lists for venting instructions, and/or all venting design instructions shall remain with the appliance or equipment at the completion of the installation.

VENTING

WARNING

THE INSTRUCTIONS IN THIS SECTION ON VENTING MUST BE FOLLOWED TO AVOID CHOKED COMBUSTION OR RECIRCULATION OF FLUE GASES. SUCH CONDITIONS CAUSE

SOOTING OR RISKS OF FIRE AND ASPHYXIATION.

Heater must be prote cte d from freezing dow ndr afts during shutdown periods.

Page 9

US DIRECT VENT

TO PREVENT EXHAUSTING PRODUCTS FROM CIRCULATING TO THE AIR INTAKE IN WINDY/COLD AREAS, THE MAXIMUM PRACTICAL DISTANCE BETWEEN THESE TWO TERMINALS IS RECOMMENDED.

CANADIAN DIRECT VENT

CAUTION

FIGURE 5.

Page 10

US HORIZONTAL VENT

TO PREVENT EXHAUSTING PRODUCTS FROM CIRCULATING TO THE AIR INTAKE IN WINDY/COLD AREAS, THE MAXIMUM PRACTICAL DISTANCE BETWEEN THESE TWO TERMINALS IS RECOMMENDED.

CANADIAN HORIZONTAL VENT

CAUTION

FIGURE 6.

Page 11

WARNING

NEVER OPERATE THE HEATER UNLESS IT IS VENTED TO THE

OUTDOORS AND HAS ADEQUATE AIR SUPPLY TO AVOID RISKS OF IMPROPER OPERATION, FIRE, EXPLOSION OR ASPHYXIATION.

VENT PIPE TERMINATION

NOTE: Before installing venting, determine place of vent pipe termination. See Figure 5 and 6 before proceeding.

CAUTION

DO NOT TERMINATE THE VENTING WHERE NOISE FROM THE EXHAUST OR INTAKE WILL BE OBJECTIONABLE. THIS IN C LUDES LOC ATIONS CL O SE TO OR ACROSS FR O M WINDOWS AND DOORS. AVOID ANCHORING THE VENT AND INTAKE PIPES DIRECTLY TO FRAMED WALLS, FLOORS OR CEILINGS UNLESS RUBBER ISO LATION PIPE HANGERS

ARE USED. THIS PREVENTS ANY VIBRATIONS FROM BEING

TRANSMITTED INTO THE LIVING SPACES.

IMPORTANT

The vent system must terminate so that proper clearances are maintained as cited in local codes or the current editions of the National Fuel Gas Code, ANSI Z223.1/NFPA 54 or the Natural Gas and Propane Installation Code, CAN/CSA-B149.1.

WARNING

WHEN THE UNIT IS TO BE SETUP AS A DIRECT VENT, THE INTAKE GUARD AND THE BALANCE PLATE MUST BE

REMOVED. THE INLET VENT PIPE MAY THEN BE GLUED TO

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

Do not terminate the exhaust vent terminal over public area where condensate or vapor can cause nuisance or hazard.

Plan the vent system layout so that proper clearances are maintained from plumbing and wiring.

Vent pipes serving power vented appliances are classied by building codes as "vent connectors". Required clearances from combustible materials must be provided in accordance with information in this manual under LOCATION OF HEATER and CLEARANCES, and with National Fuel Gas Code and local Codes.

IMPORTANT

Plan the layout of the vent system backwards from the vent termination to the appliance.

WARNING

USE ONLY THE VENT TERMINALS SUPPLIED WITH THIS UNIT. TERMINATION OF A VENT SYSTEM WITH A DEVICE OTHER THAN THE SUPPLIED VENT TERMINATIONS WILL AFFECT SYSTEM PERFORMANCE AND RESULT IN A SAFETY HAZARD.

DIRECT VENTING

The air intake provided on the unit contains an intake guard, see

Figure 7.

3"x 4" PVC REDUCER WITH INTAKE SCREEN

FIGURE 8.

DIRECT VENT TERMINAL INSTALLATION

IMPORTANT

4" VENT AND INTAKE TERMINALS ARE PROVIDED FOR NEW INSTALLATIONS. FOR REPLACEMENT OF PREVIOUS BTH 300 AND 400 WITH 3" TERMINALS, THE 4" TERMINALS ARE RECOMMENDED, BUT THE EXISTING 3" VENT/INTAKE

TERMINALS ARE PERMITTED.

NO T E : TO PREVENT EX H AUSTING PRODUC T S FR O M CIRCULATING TO THE AIR INTAKE IN WINDY/COLD AREAS, THE MAXIMUM PRACTICAL DISTANCE BETWEEN THESE TWO TERMINALS IS RECOMMENDED.

IMPORTANT

WHEN LOCATING THE TERMINALS ON A SIDEWALL, THE FOLLOWING SPECIFICATIONS PERTAINING TO TERMINAL LOCATION MUST BE FOLLOWED.

FIGURE 7.

1. The intake vent terminal and the exhaust vent terminal must terminate on the same exterior wall and must be located at a minimum of 24" (61cm) from the vertical centerline of the exhaust vent terminal (see Figure 9). In colder climates increasing the 24" (61cm) minimum to 48" (122 cm) will reduce possibility of frost over from side winds blowing exhaust vapors to the air intake of the direct the vent and is recommended for Canada.

Page 12

2. The horizontal centerline of the intake vent terminal may not be located lower than the horizontal centerline of the exhaust vent terminal (see Figure 9).

FIGURE 9.

INSTALLATION SEQUENCE

For installations in the City of Los Angeles, California Category IV PVC Pipe such as that manufactured by Brownline Pipe Company, must be used as vent pipe material.

CAUTION

Vent terminals supplied with the heater must be used.

Slide the pipe through the wall and insert into coupling on the other side of the wall, making sure that the vent terminal ends up pointed in the correct position. See Figure 10.

EXHAUST VENT TERMINAL

NOTE: BEFORE BEGINNING INSTALLATION OF ANY VENT

PIPE READ THE VENT PIPE MANUFACTURER'S INSTALLATION INSTRUCTIONS.

1. After the points of termination have been determined, use the cover plates as templates to mark the holes for the vent pipes to be inserted through the wall. BEWARE OF CONCEALED WIRING AND PIPING INSIDE OF WALL.

2. If the vent terminals are being installed on the outside of a nished wall, it may be easier to mark both the inside and outside wall. Align the holes by drilling a hole through the center of the template from the inside through to the outside. The template can now be positioned on the outside wall using the drilled holes as a centering point for the template.

3. A) MASONRY SIDE WALLS

Chisel an opening approximately 1/2" (1.3 cm) larger than the

marked circle.

B) WOODEN SIDE WALLS Drill a pilot hole approximately one quarter inch outside of the

marked circle. This pilot hole is used as a starting point for a saws-all or sabre saw blade. Cut around the marked circle staying approximately one quarter inch outside of the line. (This will allow the vent pipe to easily slide through the opening. The resulting gap will be covered by the vent terminal cover plates.) Repeat this step on the inside wall if necessary.

4. Cut a length of PVC pipe about 3.5" (8.9 cm) longer than the wall thickness at the opening.

5. Glue the intake vent terminal to the section of the pipe.

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.

INTAKE VENT TERMINAL

FIGURE 10.

VERTICAL VENT TERMINAL INSTALLATION

IMPORTANT

WHEN TERMINATING THROUGH A ROOF, THE FOLLOWING SPECIFICATIONS PERTAINING TO TERMINAL LOCATION MUST BE FOLLOWED.

1. Proper support must be provided for all pipe protruding through

the roof.

2. The vertical roof terminations should be sealed with a plumbing roof boot or equivalent ashing.

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 specications are displayed in Figure 11.

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

INSTALLATION SEQUENCE

NOTE: BEFORE BEGINNING INSTALLATION OF ANY VENT

PIPE, READ “VENT PIPE PREPARATION” SECTION.

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.

Page 13

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 sawsall 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/ashing.

3. Suspend the pipe through center of hole using proper support.

4. Slide roof boot or equivalent ashing over pipe and secure roof boot equivalent ashing to roof.

5. Seal around ashing.

6. Terminate intake terminal and exhaust vent terminal facing down.

See Figure 11.

FIGURE 11.

3. The unit is certied to a minimum amount of 4-inch pipe for the exhaust venting arrangement of 15-equivalent feet. This is the minimum amount of pipe required for the exhaust venting arrangement. The intake venting arrangement is certied to use a minimum of 0-equivalent feet of 4-inch PVC pipe.

IMPORTANT

When multiple units are direct vented through a wall (4-inch venting), all intake vent terminals should be no lower than the highest exhaust vent terminal.

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 ttings, other than the TERMINATIONS should be equivalent to PVC-DWV ttings meeting ASTM D-2665 (Use CPVC ttings, ASTM F-438 for CPVC pipe and ABS ttings, ASTM D-2661/3311 for ABS pipe. If CPVC or ABS pipe and ttings 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.

NO TE: for Water Heate r s in locati ons with hig h ambi ent temperatures (above 100°F or 38°C) and/or insufcient dilution air, it is recommended that CPVC or ABS pipe and ttings (MUST USE SUPPLIED VENT TERMINAL) be used.

INSTALLATION OF VENT SYSTEM

WARNING

THE OPTIONAL INTAKE VENTING ARRANGEMENT AND THE EXHAUST VENTING ARRANGEMENT MUST BE INSTALLED TO

RUN DIRECTLY TO THE OUTDOORS AND NOT IN ANY WAY BE CONNECTED TO ANOTHER VENTING SYSTEM (I.E. FURNACE, DRYERS OR SPACE HEATERS). IT IS CRUCIAL THAT THE

VENTING ARRANGEMENT BE KEPT SEPARATE FROM OTHER

VENTING SYSTEMS. IF THIS WARNING IS IGNORED, AND THE SYSTEM IS VENTED INCORRECTLY, IT MAY CAUSE IMPROPER OPERATION, FIRE, EXPLOSION, OR ASPHYXIATION.

1. Plan the route of the vent system from the vent termination to the planned location of the appliance. Layout the total vent system to use the minimum of vent pipe and elbows possible.

2. This unit is certied for the use of 4-inch PVC pipe for venting. The maximum length of 70-equivalent feet of 4-inch PVC pipe may be used for the intake venting arrangement and a maximum length of 70-equivalent feet of 4-inch PVC pipe may be used on the exhaust venting arrangement. If the supply gas pressure (dynamic) is set between 7" wc - 9" wc, the maximum allowed length is 80 equivalent feet for both air intake and exhaust venting. The maximum number of 90 degree elbows for the 4-inch venting is six (6) in the intake and six (6) on the exhaust. A 90 degree elbow is equal to ve (5) equivalent feet of 4-inch pipe. One 90 degree elbow is equaled to two 45 degree elbows.

5. It is important that condensate not be allowed to buildup in the exhaust vent pipe. To prevent this from happening the pipe should be installed with a slight, 1/8 inch (3mm) per 5 feet (152 cm) of pipe maximum downward slope.

6. The vent system should be supported every 5 feet (152 cm) of vertical run and every 3 feet (91cm) of horizontal run of vent pipe length.

NOTE: Stress levels in the pipe and ttings can be signicantly 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.

INLET VIEW

Table 2. VENT LENGTH TABLE

Number 4" PVC

of 90° Maximum Maximum

Elbows Feet. of Pipe Meters of Pipe

ONE (1) 65' 19.7 m TWO (2) 60' 18.2 m THREE (3) 55' 16.7 m FOUR (4) 50' 15.2 m FIVE (5) 45' 13.6 m SIX (6) 40' 12.1 m

OUTLET VIEW

FIGURE 12.

Page 14

VENT PIPE PREPARATION

1. INITIAL PREPARATION

A. Make sure the solvent cement you are planning to use is

designed for the specic application you are attempting.

B. Know the physical and chemical characteristics and limitations

of the PVC, PVC cellular core, ABS or CPVC piping materials

that you are about to use.

C. Know the reputation of your pipe and cement manufacturer

and their products.

D. Know your own qualications 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 tting technique.

E. Closely supervise the installation and inspect the nished

job before start-up.

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 ow switch be open before it will allow the blower to come on. See Figure 13.

BLOCKED OUTLET PROVER SWITCH

The Blocked Outlet Prover Switch is set up to shut the unit off when a build-up of positive pressure in the exhaust vent pipe occurs. This switch is a positive pressure switch that requires an increase in pressure to change the electrical contacts from normally closed to open. When this switch prevents the unit from igniting, most likely the exhaust is blocked by some means. Check to see if the condensate is allowed to ow freely from the exhaust elbow and for obstructions in the exhaust venting and exhaust vent terminal.

See Figure 13.

BLOCKED INLET PROVER SWITCH

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 ttings 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 ttings.

The Blocked Inlet Prover Switch is set up to shut the unit off when a build-up of negative pressure in the intake vent pipe occurs. This switch is a negative pressure switch that requires an increase in negative pressure to change the electrical contacts from normally closed to open. The switch is connected to the pressure tap on the ange 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 seventy (70) equivalent feet (24.8m) of four inch PVC vent pipe on the intake. Also verify that the intake and intake vent terminal is free of obstructions that may prevent air from entering the unit. See Figure 13.

LOW GAS PRESSURE SWITCH

The Low Gas Switch (LGS) is a single-pole, normally open pressure switch that will close its contacts when a rising pressure of 4.6 in. W.C. (1.25 Kpa) is encountered. The contacts will open when the pressure falls below the xed set point of 4.6 in. W.C. (1.25 Kpa) The LGS monitors the gas supply pressure to the heater. If the gas supply falls below 4.6 in. W.C. (1.25 Kpa), the main burner is extinguished (if heater is running) or the heater will not start up.

NOTE: LOW GAS SWITCH IS LOCATED ON INLET SIDE OF GAS VALVE. See Figure 13.

SA F E T Y PR E C A U TION: PR IMERS AN D CE M E N T S ARE

EXTREMELY FLAMMABLE AND MUST NOT BE STORED OR

USED NEAR HEAT OR OPEN FLAME. ALSO, USE ONLY IN A WELL-VENTILATED AREA.

CONTROLS AND SWITCHES

The BTH-300, 400 & 500 are equipped with four pressure switches. These switches are essential to the safe and proper operation of the unit. All switches are wired in series. The controller is set up to shut the unit down whenever there is a failure of any of the switches. It is important to understand the purpose of each switch.

BLOWER PROVER SWITCH

The Blower Prover Switch is provided on the heater to verify that the fan is operating. It is a positive pressure switch whose electrical

FIGURE 13.

ON/OFF SWITCH

The ON/OFF Switch is a single-pole, single-throw rocker switch. This switch provides 120VAC from the line source to the heater.

Page 15

CAUTION

THE WATER HEATER IS POLARITY SENSITIVE. BEFORE APPLYING ELECTRICITY TO THIS HEATER BE CERTAIN THAT SUPPLY NEUTRAL WIRE TO GROUND CHECK INDICATES ZERO

VOLTAGE.

HOT SURFACE IGNITER

The Hot Surface Igniter is a device that ignites the main burner by high temperature (>1800°F or >982°C). When 120VAC is applied to the igniter, sufcient heat is generated to ignite the main burner. Although improvements have been made to strengthen the igniter, it is fragile and care must be taken when handling the igniter to prevent breakage.

GAS PIPING

Contact your local gas service company to ensure that adequate gas service is available and to review applicable installation codes

for your area.

Size the main gas line in accordance with Table 3. The gures shown are for straight lengths of pipe at 0.5 in. W.C. (125Pa) pressure drop, which is considered normal for low pressure systems Note that ttings such as elbows and tees will add to the pipe pressure drop.

CAUTION

DO NOT USE FLEXIBLE GAS PIPING.

TABLE 3. MAXIMUM CAPACITY OF PIPE IN CUBIC FEET OF GAS PER HOUR (Based upon a Pressure Drop of 0.5 inch Water Column

and 0.6 Specic Gravity Gas and max. gas pressure of 0.5 psig).

LENGTH NORMAL IRON PIPE SIZES (INCHES) IN INPUT IN THOUSANDS BTU/HR

FEET 1 1/4" 1 1/2" 2" 2 1/2" 3" 4" 10 1400 2100 3960 6300 11000 23000 20 950 1460 2750 4360 7700 15800 30 770 1180 2200 3520 6250 12800 40 660 990 1900 3000 5300 10900 50 580 900 1680 2650 4750 9700 60 530 810 1520 2400 4300 8800 70 490 750 1400 2250 3900 8100 80 460 690 1300 2050 3700 7500 90 430 650 1220 1950 3450 7200 100 400 620 1150 1850 3250 6700 125 360 550 1020 1650 2950 6000 150 325 500 950 1500 2650 5500 175 300 460 850 1370 2450 5000 200 430 800 1280 2280 4600

LENGTH NORMAL IRON PIPE SIZES (INCHES) IN INPUT IN KW METERS 1 1/4" 1 1/2" 2" 2 1/2" 3" 4"

3.0 410 615 1160 1845 3221 6735

6.1 278 428 805 1277 2255 4626

9.1 225 346 644 1031 1830 3748

12.2 193 290 556 878 1552 3192

15.2 170 264 492 776 1391 2840

18.3 155 237 445 703 1259 2577

21.3 143 220 410 659 1142 2372

24.4 135 202 381 600 1083 2196

27.4 126 190 357 571 1010 2108

30.5 117 182 337 542 952 1962

38.1 105 161 299 483 864 1757

45.7 95 146 278 439 776 1610

53.3 88 135 249 401 717 1464

61.0 126 234 375 688 1347

WARNING

THE HEATER IS NOT INTENDED FOR OPERATION AT HIGHER

THAN 11.0" WATER COLUMN (2.74 Kpa) FOR NATURAL GAS AND

14.0" W.C. (3.49kPa) FOR PROPANE GAS SUPPLY PRESSURE.

HIGHER GAS SUPPLY PRESSURES REQUIRE SUPPLEMENTAL REDUCING SERVICE REGULATION. EXPOSURE TO HIGHER GAS SUPPLY PRESSURE MAY CAUSE DAMAGE TO THE GAS CONTROLS WHICH COULD RESULT IN FIRE OR EXPLOSION. IF OVERPRESSURE HAS OCCURRED SUCH AS THROUGH IM P R O PER TESTI N G OF GAS LINES OR EMER G E N C Y MALFUNCTION OF THE SUPPLY SYSTEM THE GAS VALVE MUST BE CHECKED FOR SAFE OPERATION. MAKE SURE THAT

THE OUTSIDE VENTS ON THE SUPPLY REGULATORS AND THE

SAFETY VENT VALVES ARE PROTECTED AGAINST BLOCKAGE. THESE ARE PARTS OF THE GAS SUPPLY SYSTEM, NOT THE HEATER. VENT BLOCKAGE MAY OCCUR DURING ICE STORMS.

IT IS IMPORTANT TO GUARD AGAINST GAS VALVE FOULING

FROM CONTAMINANTS IN THE GAS WAYS. SUCH FOULING MAY CAUSE IMPROPER OPERATION, FIRE OR EXPLOSION.

IF COPP ER SUP PLY LINES ARE USE D THEY MUST BE INTERNALLY TINNED AND CERTIFIED FOR GAS SERVICE.

BEFORE ATTACHING THE GAS LINE BE SURE THAT ALL GAS PIPE IS CLEAN ON THE INSIDE.

TO TRAP ANY DIRT OR FOREIGN MATERIAL IN THE GAS

SUPPLY LINE, A DIRT LEG (SOMETIMES CALLED A SEDIMENT TRAP OR DRIP LEG) MUST BE INCORPORATED 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 NFPA 54 OR THE NATURAL GAS AND PROPANE INSTALLATION CODE CAN/CSA-B149.1.

FIGURE 14.

CONNECTION OF GAS PIPE

1. When connecting gas pipe to unit, apply wrench to ange only.

Note: Do not use wrench on gas valve or gas bracket.

2. PERFORM THE GAS LEAK TEST ANY TIME WORK IS DONE

ON A GAS SYSTEM TO AVOID THE POSSIBILITY OF FIRE OR

EXPLOSION WITH PROPERTY DAMAGE, PERSONAL INJURY

OR LOSS OF LIFE.

The Gas Leak Test is performed as follows: Paint pipe connections upstream of gas control with a rich soap and water solution to test for leaks before operating main burner. Bubbles indicate gas leak. To stop leak, tighten pipe connections. After piping connections are checked, turn on main burner. With main burner in operation, paint pipe joints (including anges), pilot gas tubing connections and control inlet and outlet with rich soap and water solution. Bubbles indicate gas leak. To stop leak, tighten ange screws, joints and pipe connections. Replace part if leak can’t be stopped.

Page 16

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 rst two threads. Use compounds resistant to the action of liqueed petroleum gases.

DI S C ONNECT THE APPLIAN C E AN D ITS MANUAL GAS

SHUTOFF VALVE FROM THE GAS SUPPLY PIPING SYSTEM

DURING ANY SUPPLY PRESSURE TESTING EXCEEDING 1/2 PSIG (3.45Kpa). GAS SUPPLY LINE MUST BE CAPPED WHEN DISCONNECTED FROM THE HEATER. FOR TEST PRESSURES OF 1/2 PSIG (3.45Kpa) OR LESS, THE APPLIANCE NEED NOT BE DISCONNECTED, BUT MUST BE ISOLATED FROM THE SUPPLY PRESSURE TEST BY CLOSING THE MANUAL GAS

SHUTOFF VALVE.

BEFORE PLACING THE HEATER IN OPERATION, CHECK FOR GAS LEAKAGE. USE SOAP AND WATER SOLUTION OR OTHER MATERIAL ACCEPTABLE FOR THE PURPOSE OF LOCATING GAS LEAKS. DO NOT USE MATCHES, CANDLES, FLAME OR OTHER SOURCES OF IGNITION FOR THIS PURPOSE.

PURGING

RELIEF VALVE

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 WATER HEATER, THE RELIEF VALVE(S) MUST NOT BE REMOVED OR PLUGGED.

In addition to the appliance relief valve, each remote storage tank which may be used in conjunction with this appliance shall also be installed with a properly sized, rated and approved temperature (ANSI) and pressure (ASME) relief valve(s). This relief valve shall comply with the standard for relief valves and automatic gas shutoff devices for hot water supply systems. ANSI Z21.22-CSA 4.4.

Your local code authority may have other specic relief valve requirements.

WARNING

THE PURPOSE OF A RELIEF VALVE IS TO AVOID EXCESSIVE PRESSURE OR TEMPERATURE INTO THE STEAM RANGE, WHICH MAY CAUSE SCALDING AT FIXTURES, TANK EXPLOSION, SYSTEM OR HEATER DAMAGE. NO VALVE IS TO BE PLACED BETWEEN THE RELIEF VALVE AND THE TANK.

Gas line purging is required with new piping or systems in which air has entered.

CAUTION

PURGING SHOULD BE PERFORMED BY PERSONS EXPERIENCED IN THIS TYPE OF GAS SERVICE. TO AVOID RISK OF FIRE OR EXPLOSION, PURGE DISCHARGE MUST NOT ENTER CONFINED AREAS OR SPACES WHERE IGNITION CAN OCCUR. THE AREA MUST BE WELL VENTILATED AND ALL SOURCES OF IGNITION MUST BE INACTIVATED OR REMOVED.

GAS METER SIZE - CITY GASES ONLY

Be sure that the gas meter has sufcient capacity to supply the full rated gas input of the water heater as well as the requirements of all other gas red 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 VALVES

WARNING

SHOULD OVERHEATING OCCUR OR THE GAS SUPPLY FAIL TO SHUT OFF, TURN OFF THE MANUAL GAS CONTROL VALVE TO THE APPLIANCE.

A DRAIN LINE MUST BE CONNECTED TO THE RELIEF VALVE TO DIRECT DISCHARGE TO A SAFE LOCATION TO AVOID SCALDING OR WATER DAMAGE. THIS LINE MUST NOT BE REDUCED FROM THE SIZE OF THE VALVE OUTLET AND MUST NOT CONTAIN VALVES OR RESTRICTIONS, NOR SHOULD IT BE LOCATED IN FREEZING AREAS. DO NOT THREAD OR CAP THE END OF THIS LINE. RESTRICTED OR BLOCKED DISCHARGE WILL DEFEAT THE PURPOSE OF THE VALVE AND IS UNSAFE. THE DISCHARGE LINE SHALL BE INSTALLED TO ALLOW COMPLETE DRAINAGE OF BOTH THE VALVE AND LINE.

WATER LINE CONNECTIONS

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

The water heater may be installed by itself, or with a separate storage tank. When used with a separate storage tank, the circulation may be either by gravity or by means of circulating pump. When a circulating pump is used, it is important to note that the ow rate should be slow so that there will be a minimum of turbulence inside the heater.

CLOSED SYSTEM

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 eld 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.

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

Page 17

codes or contact the water supplier or local plumbing inspector on how to control this situation.

WATER (POTABLE) HEATING AND SPACE HEATING

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

2. Toxic chemicals, such as those used for boiler treatment, shall NEVER be introduced into this system.

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

4. When the system requires water for space heating at temperatures higher than required for domestic water purposes, a tempering valve must be installed. Please refer to installation diagrams on pages 30 through 35 in back of manual for suggested piping arrangements.

HEATER WIRING

CLEAN ELECTRICITY FOR PROPER OPERATION. INSTALLING THE HEATER ON A BRANCH CIRCUIT THAT HAS ELECTRONIC NOISE, IS SUBJECT TO FLUCTUATIONS IN VOLTAGE LEVEL OR HAS AN AP P LIANCE WHICH GENERATES EMF OF RFI INTERFERENCE CAN CAUSE THE CONTROLLER TO MALFUNCTION. A HIGH QUALITY POWER CONDITIONER MUST BE INSTALLED IF THE ABOVE CONDITIONS EXIST. MALFUNCTIONS CAUSED BY A POOR ELECTRICAL SUPPLY ARE NOT COVERED UNDER YOUR WARRANTY.

The controller is wired to the heater as shown in gures 15 & 16. The model and rating plate provides the electrical information needed to size the complete heater branch supply.

All electrical work must be installed in accordance with the National Electrical Code, NFPA 70 or the Canadian Electrical Code, CSA C22.1 and local requirements.

When installed, the appliance must be electrically grounded in accordance with local codes or, in the absence of local codes, with the National Electrical Code, ANSI/NFPA 70 or the Canadian Electrical Code, CSA C22.1.

IF ANY OF THE ORIGINAL WIRE AS SUPPLIED WITH THE APPLIANCE MUST BE REPLACED, IT MUST BE REPLACED WITH 105°C OR ITS EQUIVALENT, EXCEPT IN THE BURNER HOUSING. IN THIS CASE USE 200°C WIRE.

THE COMPUTER CONTROL REQUIRES A SOURCE OF STABLE

DO NOT ENERGIZE THE BRANCH CIRCUIT BEFORE THE HEATER TANK IS FILLED WITH WATER.

NOTE: This controller is Polarity Sensitive. If the Hot and Neutral Supply Voltage is reversed, the controller will not sense ame. Verify polarity before connecting the unit.

Page 18

BTH 300 WIRING DIAGRAM

FIGURE 15.

Page 19

BTH 400 AND 500 WIRING DIAGRAM

FIGURE 16.

Page 20

OPERATION

SEQUENCE OF OPERATION

Typical Control/Appliance Operating Sequence

1. When the control is powered, it should display the unit model, water temperature, setting temperature and heater status.

2. If the control determines that the actual water temperature inside the tank is below the programmed temperature setpoint less the differential, a call for heat is activated.

3. The control then performs selected system diagnostic checks. This includes conrming the proper state of the air/gas switches and ECO limit device.

4. If all checks are successfully passed, the combustion blower is energized for the pre-purge cycle.

5. When the pre-purge cycle is complete, power is applied to the ignitor element for the ignitor warm-up period.

6. At the conclusion of the igniter warm-up period, the gas valve will open, allowing gas to enter the burner chamber.

7. The igniter will remain on for a short predetermined time period, then will be turned off.

8. The control will monitor the ame sense probe to conrm a ame is present. If a ame is not veried within predetermined time period, the gas valve will immediately be closed, and the blower will continue to run for approximately 30 seconds interpurge. The control will try for ignition two more times before lockout.

inside the tank. The second temperature on this screen is the Operating Set Point. The Operating Set Point is the temperature at which the water heater will maintain the water inside the tank. The third line on the screen is a text description of the Operational State of the water heater (please see Operating States for more details).

The row of status icons describe graphically operational details

of the heater. Following is a legend of all the status icons:

9. If a ame is conrmed, the control will enter the heating mode where it will continue heating the tank water until the setpoint temperature plus differential is reached. At this point, the gas valve is closed and the control enters the post-purge cycle.

10. The combustion blower will run for the duration of the post purge cycle to purge the system of all combustion gases. When the post purge cycle is complete, the blower is de-energized and will coast to a stop.

11. The control will now enter the idle state while continuing to monitor the internal tank water temperature and the state of other system devices. If the temperature drops below the setpoint value less differential, the control will automatically return to step 2 and repeat the entire operating cycle.

ELECTRONIC CONTROL

1. Overview

Interaction with the water heater controller is done through an up,

a down and three operation buttons. These buttons are shown in the following illustration. Operation of the three lower buttons is dened immediately above them on the screen. The UP and DN buttons are used to navigate through the menus and make adjustments to the water heater.

While the water heater is operating, the user interface will display

the desktop screen (if there are no active faults or warnings). An example of this screen is shown in the following illustration. The rst temperature on this screen is the temperature of the water

2. Operating States

In the main desktop screen, there are some specic Operating

States that are indicated on the status line. These are summerized in the following table:

Page 21

3. Adjusting the Operating Set Point The Operating Set Point of this water heater determines the regulated temperature for the water in the tank. This parameter is adjusted

in the Temperature menu. Items in this menu allow you to monitor different temperature readings in the tank along with adjusting the

Operating Set Point and Differential.

Page 22

4. Changing the Display Units

The display interface to the heater has the option of selecting between degrees and Fahrenheit and degrees Celsius for temperature

displays. This can be found in the "Display Settings" menu. Also in this menu, you may adjust how the backlight operates and the contrast of the LCD screen.

Fault and Warning Conditions

This water heater is equipped with electronic controls that have the ability to monitor almost all aspects of the water heater operation. In

the case that there is an undesirable or unsafe condition that occurs, the water heater controls will detect this condition and determine the appropriate action. Part of this is displaying the information on the LCD in plain text that accurately describes the condition and diagnostics information that can be used to correct the issue.

There are two types of conditions that can occur during operation. These are: Warnings and Faults:

• Warnings: This is a non-safety related condition that the control has detected that may cause the water heater to operate in a less

than optimal condition, but does not pose a safety concern.

NOTE: When these conditions occur, continued heating cycles will continue and the heater will attempt to regulate the water in the

tank to the Operating Set Point.

Example of a Warning:

Page 23

• Faults: This is a safety related condition that has been detected by the heater. NOTE: When these conditions occur, the water heater will not continue any further heating cycles and the water will no longer be

heated until the condition is corrected and, in most cases, power has been cycled.

Example of a Fault:

Advanced Diagnostics Information

When a fault or warning has been declared, advanced information can be found in the control. By pressing the Advanced button,

detailed information can be found regarding diagnosing and resolving the problem.

WAR NIN G: Usa ge of the A dva nce d inf orm ati on req uires ability equivalent to tha t of a lic ens e tra des men i n the

eld in vol ved .

6. Access to the Current Fault or Warning When a fault or warning has been detected by the control, it will automatically be displayed on the screen and the back light will

blink. If you choose to leave the current fault or warning by pressing the Back key, you can always return to the fault screen through the menu.

Page 24

7. Viewing the Fault History

The controller for this water heater will store a history of ten of the last Fault and Warning conditions that occurred. This is stored in the

Fault History. Along with all the information about the fault, including a estimate time of when the fault occurred, information regarding the advanced diagnostics for that fault can be accessed at any time.

Viewing Information About the Heater

The electronic control for this water heater monitors many different aspects of the water to ensure safe and optimal operation. Much

of the information monitored is available to view in two areas of the control. The rst is the "Heater Status" and; the second is "Heater Information". These items can be selected through the main menu in the same fashion as described above. In these menus, detailed information about the water heater and the current status of specic conditions can be found.

Page 25

PRIOR TO START UP - REQUIRED ABILITY

INSTALLATION OR SERVICE OF THIS WATER HEATER REQUIRES ABILITY EQUIVALENT TO THAT OF A LICENSED TRADESMAN IN THE FIELD INVOLVED. PLUMBING, AIR SUPPLY, VENTING, GAS SUPPLY AND ELECTRICAL WORK ARE REQUIRED.

Before attempting start-up, thoroughly study and familiarize yourself with the exact sequence of operation and all other details on the specic 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.

DO NOT USE THIS HEATER IF ANY PART HAS BEEN UNDER

WATER. IMMEDIATELY CALL A QUALIFIED SERVICE TECHNICIAN TO INSPECT THE HEATER AND TO REPLACE ANY PART OF THE CONTROL SYSTEM AND ANY GAS CONTROL WHICH HAS BEEN UNDER WATER.

LIGHT THE UNIT IN ACCORDANCE WITH THE OPERATING INSTRUCTIONS LABEL ATTACHED TO THE HEATER.

THESE INSTRUCTIONS ARE REPEATED IN THE LIGHTING AND

OPERATING LABEL ILLUSTRATION IN THIS MANUAL.

ADJUSTMENT PROCEDURE - INITIAL START-UP

A minimum dynamic gas supply pressure of 5.2" W.C. (1.29 kPa) for Natural Gas and 11" W.C. (2.74 kPa) for LP Gas is required before making any adjustment to the gas control pressure regulator Attempts to adjust the regulator during periods of low gas supply pressure could result in overring of the heater when the gas supply pressure returns to normal.

Th e fol l owing test equipm ent sh ould be on hand (all tes t equipment must be acclimated to ambient temperature before calibration and use.)

– Two U-tube manometers or calibration 0-10" W.C. (0-2.5Kpa) and

0-35" W.C. (0-8.7Kpa) pressure gauges.

• Attach a gas pressure gauge or manometer to the upstream side of main gas cock and a gas pressure gauge or manometer to the manifold pressure tap.

• You are now ready to begin the burner start-up procedure.

OPERATING INSTRUCTIONS

IMPORTANT

IT IS RECOMMENDED THAT A QUALIFIED SERVICE TECHNICIAN

PERFORM THE INITIAL FIRING OF THE HEATER. AT THIS TIME THE

USER SHOULD ASK THE TECHNICIAN ANY QUESTIONS IN REGARD TO THE OPERATION AND MAINTENANCE OF THE UNIT.

CAUTION

BEFORE PROCEEDING WITH THE OPERATION OF THE UNIT, MAKE SURE HEATER AND SYSTEM ARE FILLED WITH WATER

AND ALL AIR IS EXPELLED FROM HEATER AND PIPING.

NEVE R OPERATE THE HEATER WITHO UT FIRST BEING CERTAIN IT IS FILLED WITH WATER AND A TEMPERATURE AND

A PRESSURE RELIEF VALVE IS INSTALLED IN THE RELIEF VALVE OPENING OF THE HEATER. DO NOT ATTEMPT TO OPERATE

HEATER WITH COLD WATER INLET VALVE CLOSED.

1. Check gas line pressure with a manometer, adjust the gas supply line pressure per table 4.

2. Check manifold pressure (see Table 4) using a pressure gauge (manometer) connected to the manifold pressure tap on the gas control valve, (Figure 15).

If full rate adjustment is required, remove cover screw from top of the gas control valve, (Figure 15).

Using a small screwdriver, turn adjusting screw clockwise to increase or counterclockwise to decrease gas pressure to obtain 4.0" W.C. (0.996 kPa) for Natural Gas and 10" W.C. (2.49 kPa) for LP gas.

3. Cycle the burner on and off several times to check its operation.

4. Check the operation of the limit and operating controls.

5. Check the vent system seams and joints and ensure that there is no discharge of ue products into the room.

6. Check the input rate:

For appliance installation locations with elevations above 10,000 feet (3,048 m) refer to HIGH ALTITUDE INSTALLATIONS section of this manual.

a. Attach a pressure gauge (manometer) to the manifold pressure

tap (Figure 16) and refer to Table 4 for correct pressure.

b. Use this formula to “clock” the meter. Be sure other gas

consuming appliances are not operating during this interval.

FILLING:

1. Close the heater drain valve.

2. Open a nearby hot water faucet to permit the air in the system to escape.

3. Fully open the cold water inlet pipe valve allowing the heater and piping to be lled.

4. Close the hot water faucet as water starts to ow.

5. The heater is ready to be operated.

THE MAIN MANUAL GAS SHUTOFF VALVE MUST HAVE BEEN CLOSED FOR AT LEAST FIVE (5) MINUTES. THIS WAITING PERIOD IS AN

IMPORTANT SAFETY STEP. ITS PURPOSE IS TO PERMIT GAS THAT

MIGHT HAVE ACCUMULATED IN THE COMBUSTION CHAMBER TO CLEAR. IF YOU DETECT GAS AT THE END OF THIS PERIOD, DO NOT PROCEED WITH LIGHTING. RECOGNIZE THAT GAS ODOR, EVEN IF IT SEEMS WEAK, MAY INDICATE THE PRESENCE OF ACCUMULATED GAS SOMEPLACE IN THE AREA WITH A RISK OF FIRE OR EXPLOSION.

SEE THE FRONT PAGE FOR STEPS TO BE TAKEN.

3600 T

T = Time in seconds to burn 1 cubic foot of gas. (With a stopwatch

H = Heating value of gas (in Btu’s per cubic foot of gas). Btuh = Actual heater input rate, in Btuh. EXAMPLE: (Using BTH-300 heater) T = 12.6 seconds

H = 1050 Btu/ft. BTUH = ?

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

Should it be necessary to adjust the gas pressure to the burner,

to obtain the full input rate, the steps below should be followed:

X H = Btuh

read the gas meter and measure the amount of time required for the heater to consume 1 cubic foot of gas.)

3600

1050 = 300,000 Btuh (87.9 kW)

12.6

Page 26

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

adjust the pressure by turning the adjusting screw with a small screwdriver. In this example, with heater running on natural gas, do not exceed 4.0" (0.996 kPa) Water Column.

Clockwise to increase gas pressure and input rate.

Counterclockwise to decrease gas pressure and input rate.

d. “Clock” the meter as in step (b) above

LIGHTING AND OPERATION INSTRUCTIONS

FOR YOUR SAFETY READ BEFORE OPERATING

e. Repeat steps (c) and (d) until the specied 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 sufcient gas pressure at the valve, check to ensure the unit is equipped with the correct orice.

WARNING

A. This appliance does not have a pilot. It is equipped with

an ignition device which automatically lights the burner.

Do not try to light the burner by hand.

B. BEFORE OPERATING smell all around the appliance area

for gas. Be sure to smell next to the oor because some gas is heavier than air and will settle on the oor.

“WHAT TO DO IF YOU SMELL GAS”

• Do not try to light any appliance.

• Do not touch any electric switch; do not use any telephone

in your building.

• Immediately call your gas supplier from a neighbor ’s

IF YOU DO NOT FOLLOW THESE INSTRUCTIONS EXACTLY A FIRE OR EXPLOSION MAY RESULT CAUSING PROPERTY DAMAGE, PERSONAL INJURY OR LOSS OF LIFE.

OPERATING INSTRUCTIONS

1. STOP! Read the safety information above on this label.

2. Set thermostat to lowest setting.

3. Turn off all electric power to the appliance.

4. This appliance is equipped with an ignition device which automatically lights the burner. Do not try to light the burner by hand.

telephone. Follow the gas supplier’s instructions.

• If you cannot reach your gas supplier, call the fire department.

C. Use only your hand to push in or turn the gas control

knob. Never use tools. If the knob will not push in or turn by hand, don’t try to repair it, call a qualied service technician. Force or attempted repair may result in re

or explosion.

D. Do not use this appliance if any part has been under water.

Immediately call a qualied service technician to inspect

the appliance and to replace any part of the control system

and any gas control which has been under water.

9. Set thermostat to desired setting.

10. If the appliance will not operate, follow the instructions

“To Turn Off Gas To Appliance” and call your service

technician or gas supplier.

5. Push in gas control knob slightly and turn clockwise

to “OFF”.

6. Wait five (5) minutes to clear out any gas. I f y o u t h e n smell gas, STOP! Follow “B” in the safety information

above on this label. If you don’t smell gas, go on to

the next step.

7. Turn gas control knob counterclockwise to “ON”.

8. Turn on all electric power to the appliance.

FOR YOUR SAFETY READ BEFORE OPERATING

1. Set the thermostat to lowest setting.

2. Turn off all electric power to appliance if service is to be performed.

3. Push in gas control knob slightly and turn clockwise

to “OFF”. Do not force.

Page 27

WARNING

UNDER NO CIRCUMSTANCES SHOULD THE INPUT EXCEED THE RAT E SHOW N ON THE HE ATER RAT I N G PL AT E. OVERFIRING COULD RESULT IN DAMAGE OR SOOTING OF

THE HEATER.

CATHODIC PROTECTION

CAUTION

HYDROGEN GAS CAN BE PRODUCED IN A HOT WATER

SYSTEM SERVED BY THIS HEATER THAT HAS NOT BEEN

USED FOR A LONG PERIOD OF TIME (GENERALLY TWO WEEKS OR MO RE ) . 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 ow. There should be no smoking or open ame near the faucet at the time it is open.

HIGH ALTITUDE INSTALLATIONS

WARNING

BT H H EATE R S ARE C ER T I FI ED FO R US E W I TH OU T MODIFI C AT I ON FO R ALTIT U D E S UP TO 10,000 FEET. INS TA LL ATI O N S AB OV E 10 , 0 00 F E ET M AY R E QU I RE RE PLACE MENT OF THE BUR NER ORIFICE . CALL TH E TECHNICAL INFORMATION CENTER AT (800) 527-1953 FOR REQUIREMENTS.

Some gas utility companies derate their gas for altitude, making it unnecessary to install high altitude orices. Call the local gas or utility company to verify BTU content.

Due to the input rating reduction at high altitudes, the output rating of the appliance is also reduced and should be compensated for in the sizing of the equipment for applications.

MAINTENANCE

PRECAUTIONS

IF THE UNIT IS EXPOSED TO OR EXHIBITS THE FOLLOWING, DO NOT OPERATE HEATER UNTIL ALL CORRECTIVE STEPS HAVE BEEN MADE BY A QUALIFIED SERVICEMAN.

1. FLOODING TO OR ABOVE THE LEVEL OF THE BURNER OR

CONTROLS

2. EXTERNAL DAMAGE

3. FIRING WITHOUT WATER

4. SOOTING

NEVER OPERATE THE HEATE R WITHOUT FIRST BEING CERTAIN IT IS FILLED WITH WATER AND A TEMPERATURE

AND PRESSURE RELIEF VALVE IS INSTALLED IN THE RELIEF VALVE OPENING OF THE HEATER.

SHOULD OVERHEATING OCCUR OR THE GAS SUPPLY FAIL TO 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 25.

The sequence of operation of the unit is provided on page 20.

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

Th e high limit (n ot adj u stabl e ) is fac tory se t to cut out at 202°F (94°C). The controller will not be reset until water temperature drops to below 140°F (61°C).

TABLE 4.

GAS SUPPLY SPECIFICATIONS Nat. Gas LP Gas

Max. Gas Supply Pressure W.C. 11.00 14.00 Max. Gas Supply Pressure kPa 2.74 3.49 Nominal Gas Supply Pressure W.C. 7.00 11.00 Nominal Gas Supply Pressure kPa 1.74 2.74 Minimum Gas Supply Pressure W.C.* 5.20 11.0 Minimum Gas Supply Pressure kPa* 1.54 2.74 Manifold Gas Supply Pressure W.C. 4.00 10.0

Manifold Gas Supply Pressure kPa 1.25 2.49

* Minimum pressure for purposes of rate adjustment

GENERAL

K E EP A PP L IA N CE AR EA C LE AR AN D F RE E F RO M CO M B US TI BL E MAT ER IA LS , GA S OL IN E AN D O T HE R FLAMMABLE VAPORS AND LIQUIDS. (SEE WARNING ON PAGE 6, LOCATING THE HEATER).

Water heat er mainte nanc e inc lude s per iodi c tank flushi ng 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

Fo llow ing are the inst ructions for perform ing some of the recommended maintenance. Unit inspection and adjustment should be performed by a competent technician.

COMPONENT OPERATION INTERVAL REQUIRED

Tank Sediment Monthly Flushing Removal

Tank Lime Scale Semi UN-LIME Removal Annually Delimer

Powered Anode Inspect Semi System Annually

Relief Valve Inspect Semi Annually

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.

NOTE:

Service at 1-800-265-8520 for approved alternatives.

UN•LIME is not available in Canada. Please call Customer

Page 28

FLUSHING

1. Turn off the heater electrical disconnect switch.

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

3. Close the drain valve when nished ushing.

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.

Sediment and lime scale removal may be accomplished through the cleanout opening furnished on the heater, see Figure 24. The heater must be drained, see DRAINING, before removing cleanout cover on tank.

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 REMOVAL

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 REMOVAL

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 efciency 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.

FIGURE 24.

To dissolve and remove the more stubborn mineral deposits, A.O. Smith UN•LIME® Professional Delimer should be used. NOTE: UN•LIME is not available in Canada. Please call Customer Service at 1-800-265-8520 for approved alternatives.

A.O. Smith UN•LIME® Professional Delimer is an easy to handle patented food grade acid formulated specically for lime scale removal from all types of water using equipment. Available in 1 gallon (3.8L) (part no. 4763) and 5 gallon (19L) (part no. 4813) sizes. Hydrochloric base acids are not recommended for use on glass-lined tanks. A.O. Smith Form No. 4800 Rev. 8, entitled “Why, When and How”, describes tank cleaning methods and materials. UN•LIME and the booklet may be obtained through your A.O. Smith dealer or distributor.

The cleanout opening is shown in Figure 24. To clean heater through cleanout opening, proceed as follow:

1. Turn off water inlet valve, the heater electrical disconnect switch and open drain valve.

2. Remove outer cover plate from lower side of heater jacket.

3. Remove cover from cleanout opening.

4. Remove lime, scale or sediment using care not to damage the glass-lining.

5. Inspect cleanout plate gasket: If new gasket is required, replace with A. O. Smith part no. 99038.

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.

Example 2 :

Initial inspection shows 2" (5cm) of lime accumulation. Therefore,

the heater should be delimed every 3 months.

8. Check for water leakage.

9. Replace outer jacket cover plate.

Page 29

POWERED ANODE SYSTEM

To insure a long, trouble-free operating life, BTH 300, 400 and 500 are factory equipped with a powered anode system. The anodes are of a permanent design and do not need replacing unless damaged.

DRAIN VALVE AND ACCESS PANELS

The heaters are equipped with a 3/4" drain valve.

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.

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.

An access panel covers the cleanout opening in the tank which is sealed by a gasket and cover, see Figure 24.

RELIEF VALVE

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 ow, 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.

CAUTION

BEFORE MANUALLY OPERATING THE VALVE, MAKE SURE THAT A DRAIN LINE HAS BEEN ATTACHED TO THE VALVE TO DIRECT THE DISCHARGE TO AN OPEN DRAIN. FAILURE TO TAKE THIS PRECAUTION COULD MEAN CONTACT WITH EXTREMELY HOT WATER PASSING OUT THE VALVE DURING THIS CHECKING OPERATION.

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 TEMPERATURE AND PRESSURE RELIEF VALVE. THIS IS NOT A SOLUTION AND CAN CREATE A

HAZARDOUS SITUATION.

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 30

INSTALLATION DIAGRAMS

ONE TEMPERATURE - ONE HEATER VERTICAL STORAGE TANK FORCED CIRCULATION

WITH OR WITHOUT BUILDING RECIRCULATION

CA U T I O N: I F BU IL D I NG

COL D WATER SUPPLY HAS A BACK-FLOW PREVENTER, CH E CK VALVE OR WAT ER METER WITH CHECK VALVE

PROVISIONS FOR THERMAL

EXPANSION OF WATER IN THE HOT WATER SYSTEM MUST

BE PROVIDED

NOT E: C ON NECT RETURN LI N E F R O M H O T WA T E R CIRCULATING LOOP (IF USED) TO COLD WATER INLET LINE.

* PIPE TO OPEN DRAIN

IN S TAL L IN ACCO R DAN C E WITH LOCAL CODES

ONE TEMPERATURE - ONE HEATER HORIZONTAL STORAGE TANK

FORCED CIRCULATION WITH OR WITHOUT BUILDING RECIRCULATION

DANGER

TEMPERATURE SETTING SHOULD NOT EXCEED SAFE TEMPERATURE AT FIXTURES. SEE WATER TEMPERATURE CONTROL WARNING ON PAGE

3. IF HIGH ER PREHE AT TEMPERATURES ARE

NECESSARY TO OBTAIN ADEQUATE BOOSTER OUTPUT, ADD AN ANTI-SCALD VALVE FOR HOT WATER SUPPLIED TO FIXTURES.

*PIPE TO OPEN DRAIN

INSTALL IN ACCORDANCE WITH LOCAL CODES

Page 31

TWO TEMPERATURE - ONE HEATER HIGH TEMPERATURE

WITH OR WITHOUT BUILDING RECIRCULATION

TEMP ER ATU RE SET TING SHOU LD NOT EXCE ED

DANGER

SAFE T EM PE RATURE AT FIX TU RE S. SEE WATER TEMPERATURE CONTROL WARNING ON PAGE 3. IF HIGHER PREHEAT TEMPERATURES ARE NECESSARY TO OBTAIN ADEQUATE BOOSTER OUTPUT, ADD AN ANTI-SCALD VALVE FOR HOT WATER SUPPLIED TO

FIXTURES.

CAUTION: IF BUILDING COLD WATER SUPPLY HAS A BACK-FLOW PREVENTER, CHECK VALVE OR WATER ME T ER WITH CH E C K VALVE PRO V I SIO N S FO R THERMAL EXPANSION OF WATER IN THE HOT WATER

SYSTEM MUST BE PROVIDED.

*PIPE RELIEF VALVE TO OPEN DRAIN.

N O T E : I F T EM P E RE D W AT ER I S RECIRCULATED, RETURN LINE SHOULD BE CONNECTED AT POINT “A”.

INSTALL IN AC CORDANCE WITH LOCAL CODES.

Page 32

TWO TEMPERATURE - TWO HEATERS HIGH TEMPERATURE

WITH OR WITHOUT BUILDING RECIRCULATION

TWO TEMPERATURE - THREE HEATERS (TWO PRE-HEATERS/ONE BOOSTER HEATER)

WITH OR WITHOUT BUILDING RECIRCULATION

MUST BE IDENTICAL HEATERS

FOR MULTIPLE HEATER INSTALLATION SEE MANIFOLD KIT

SPECIFICATIONS, PAGE 35.

CAUTION: IF BUILDING COLD WATER SUPPLY HAS A BACKFLOW PREVENTER, CHECK VALVE OR WATER METER WITH CHECK VALVE PROVISIONS FOR THERMAL EXPANSION OF WATER IN THE HOT WATER SYSTEM MUST BE PROVIDED.

DANGER

TE MPER ATURE SETTI NG SHOULD NOT EXCEED SAFE TEMPERATURE AT FIXTURES. SEE WATER TEMPERATURE CONTR OL WARNING ON PAGE 3. IF HIGHER PREHE AT TEMPERATURES ARE NECESSARY TO OBTAIN ADEQUATE BOOSTER OUTPUT, ADD AN ANTI-SCALD VALVE FOR HOT WATER SUPPLIED TO FIXTURES.

Page 33

TWO TEMPERATURE - TWO HEATERS (ONE PRE-HEATER/ONE BOOSTER HEATER)

WITH OR WITHOUT BUILDING RECIRCULATION

TEMPERATURE SETTING SHOULD NOT EXCEED SAFE TEMPERATURE

DANGER

AT FIXTURES. SEE WATER TEMPERATURE CONTROL WARNING ON PAGE 3. IF HIGHER PREHEAT TEMPERATURES ARE NECESSARY TO OBTAIN ADEQUATE BOOSTER OUTPUT, ADD AN ANTI-SCALD VALVE FOR HOT WATER SUPPLIED TO FIXTURES

* PIPE RELIEF VALVE TO OPEN DRAIN

** 140°F (60°C)TO 150°F (66°C) SHOULD BE MAXIMUM WATER

TEMPERATURE MAINTAINED IN THE PRE-HEATERS.

120°F (49°C) SHOULD BE THE MINIMUM TEMPERATURE OF

WATER IN THE PRE-HEATERS.

CONNECT CIRCULATING LINE FROM FIXTURES, IF USED,

TO COLD WATER SUPPLY LINE OF PRE-HEATER.

CONNECT CIRCULATING LINE OF 180°F (82°C) OR BOOSTED

WATER, IF USED, TO INLET WATER LINE TO BOOSTER.

INSTALL IN ACCORDANCE WITH LOCAL CODES.

Page 34

TWO TEMPERATURE - ONE HEATER HIGH TEMPERATURE

WITH RECIRCULATION OF SANITIZING LOOP

DANGER

CAUTION: IF BUILDING COLD WATER SUPPLY HAS A BACKFLOW PREVENTER, CHECK VALVE OR WATER METER WITH CHECK VALVE PROVISIONS FOR THERMAL EXPANSION OF WATER IN THE HOT WATER SYSTEM MUST BE PROVIDED.

*PIPE RELIEF VALVE TO OPEN DRAIN

INSTALL IN ACCORDANCE WITH LOCAL CODES

NOTE 1: TOGGLE SWITCH CONTROLS 180°F (82°C) WATER CIRCULATION. INSTALL ON OR CLOSE TO DISHWASHER. TOGGLE SWITCH MUST BE CLOSED (ON) DURING THE RINSE OPERATION AND OPEN (OFF) WHEN DISHWASHER IS NOT OPERATING OR WHEN ON LONG STANDBY.

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

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

IN THE TANK.

NOTE 4: IF TEMPERED WATER IS RECIRCULATED, RETURN LINE SHOULD BE CONNECTED AT POINT A.

Page 35

MULTIPLE UNIT INSTALLATIONS

Proper installation of multiple water heaters assures water ow 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 ow may have a shortened life.

Dimensions shown are for minimum space occupied by the water heaters assemblies.

Space for the venting system and unit servicing must be added.

Manifold Kits for multiple unit installations are not available from the manufacturer.

Page 36

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-red after a prolonged shutdown. HOWEVER, it is recommended that only qualied servicemen, using appropriate test equipment, be allowed to service the heater.

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

• Verify the condensate drains from the unit without restriction.

WATER IS TOO HOT

1. Refer to WATER TEMPERATURE CONTROL.

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

WARNING

FAILURE TO FOLLOW THESE INSTRUCTIONS CAN RESULT IN SERIOUS PERSONAL INJURY OR DEATH.

CAUTION:

LA B EL ALL WIRES PR I OR TO DI SCONNEC T ION WHEN SERVICIN G CON TROL S. WIRIN G ERR ORS CAN CAUSE

IMPROPER AND DANGEROUS OPERATION.

VERIFY PROPER OPERATION AFTER SERVICING.

BURNER OPERATIONAL 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.

WATER HEATER 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.

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.

WATER LEAKAGE IS SUSPECTED

1. Check to see if the water heater drain valve is tightly closed. Also check the cleanout opening for leakage.

2. The apparent leakage may be condensation which forms on cool surfaces of the heater and piping.

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

• Excessive water pressure.

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 he a t er w a s ins t a ll e d wh e n inc o m in g wat e r

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 ring at proper rate.

• Check gas pressure. Adjust to obtain required manifold

pressure.

9. Burner fan wheel may be dirty.

• 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 damaged. Refer to MAINTENANCE-RELIEF 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.

TROUBLESHOOTING

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 the gas supply volume and pressure per table 3 and 4.

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

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

• Clean fan wheel with a stiff brush.

5. Heater is properly grounded.

Page 37

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

this tubing is damaged it must be replaced. If these steps do not eliminate the problem, replace the pressure switches.

WARNING

JUMPING OUT COMPONENTS AND/OR CIRCUITS DURING TROUBLESHOOTING CAN CAUSE SERIOUS PROBLEMS WITH THE UNIT’S OPERATING SEQUENCE AND IGNITION SAFETY. IF YOU DO NOT HAVE THE PROPER TEST EQUIPMENT, I.E. A VOLT-OHM METER AND A MICROMETER, DO NOT ATTEMPT TO TROUBLESHOOT OR REPAIR A.O. SMITH EQUIPMENT.

ALTERING THE CONTROLLER AND/OR CONTROLLER WIRING IN ANY WAY COULD RESULT IN INTERNAL DAMAGE TO THE MODULE CIRCUITS, POSSIBLY ALTERING THE IGNITION SEQUENCE ALLOWING GAS VALVES TO OPEN BEFORE THE HOT SURFACE IGNITER IS UP TO IGNITION TEMPERATURE.

NOTE: ANY BYPASS OR ALTERATION OF THE UNITS SAFETIES WILL RESULT IN VOIDING THE APPLIANCE WARRANTY.

Before performing any troubleshooting familiarize yourself with the particular appliance.

Refer to the SEQUENCE OF OPERATION and the connection diagram 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 NEUTRAL WIRE TO GROUND CHECK INDICATES ZERO VOLTAGE.

MOTOR WILL NOT RUN

1. Conrm 120V AC. 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.

2. For BTH 400 and 500 a VFD (Variable Frequency Drive) is used. "rdy" (stands for ready) will be shown on display in standby heating mode. "155" (155 output Hz) shall be shown on VFD display during heater running for BTH 400. "196" will be displayed on VFD during BTH 500 running. Any other display on the VFD indicates a faulty VFD or wrong speed reference, call A.O. Smith Tech Center for assistance.

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

5. Check to see if there is resistance across the igniter terminal with an OHM meter. If there is no continuity, the igniter is broken and should be replaced.

If the igniter appears to function properly, then verify that the

inlet pressure is 11.0" Natural Gas (2.74 kPa). The gas valve supplied on this appliance is not designed to open against a higher pressure. At this time also check that the inlet pressure is not lower than the minimal gas supply pressure, as shown in Table 4: that is, for Natural Gas, 5.2" (1.29 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" (0.996 kPa) W.C. If the manifold pressure is not correct then adjust accordingly. See ADJUSTMENT PR O CEDURE in OPERATIN G INSTRUC T I ONS for th e manifold pressure adjustment procedure.

6. If the inl et and mani fol d pressures are within the limits specied 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. 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.

MOTOR RUNS, BURNER LIGHTS MOMENTARILY,

THEN LOCKS OUT

1. Reset the appliance two more times to ensure that all of the air has been purged from the gas line.

2. I f the burner lights mo me n ta r i l y bu t do e s not sustain ignitio n, veri fy that the inlet pressure is not greater than 11 . 0 " (2.7 4 kPa) W.C. or lower than the minimal gas supply pressure, as s how n in Table 4: that is, fo r Natural Gas, 5.2" (1. 29 kPa) W.C. pre ssure. Also, the manifol d pressur e should rise during the three (3) secon d trial for ignitio n to the manifold pressu re value for the individ ual unit listed in Table 4: tha t is, for Nat ura l Gas, 4.0" (0.996 kP a) W.C . If th e man i fold pressu re is not cor rect then adjust acc ord ing ly. See ADJUSTMENT PROCEDURE in OP E RATING INSTRUCT I ONS sec t ion for th e manifo l d pressur e a dju stm ent pr ocedure.

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 ame. Reverse the supply wires and try to re the unit.

Page 38

NOTE: Always turn off and disconnect main supply wiring before servicing the unit.

4. Check connecting wire to the ame sensor. Verify that the ame 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 insufcient. See VENTING.

7. Check for a maximum inlet pressure of 11" Natural Gas (2.74 kPa) W.C. and the manifold pressure as listed in Table 4: that is, for Natural Gas, 4.0" (0.996 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. Overring the heater will result in rough ignition and/or noisy operation.

8. Conrm 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. Overring is a dangerous condition that must be corrected immediately.

NOISY BURNER OPERATION

The exhaust of this unit produces some noise during ignition period. When combustion is too lean or too rich, start up noise will get worse. Check for ue gas CO2 reading, adjust gas valve manifold pressure if required to bring the ue gas CO2 to 9–9.5% level for natural gas,

10.75–11.25% for LP. 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 conned 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 ne-tune the air/gas ratio of the combustion system or locate the exhaust as far away from any occupied spaces as practical.

GAS FAILS TO SHUT OFF

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

REPLACEMENT PARTS

Replacement parts may be ordered through A.O. Smith dealers, authorized servicers or distributors. Refer to the Yellow Pages for where to call or contact the A.O. Smith Water Products Company, 125 Southeast Parkway, Franklin, TN 37068, 1-800-433-2545. When ordering parts be sure to state the quantity, part number and description of the items including the complete model and serial number as it appears on the product. Refer to the parts list for more information.

Page 39

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 rst 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 efcient 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 efcient model required. The warranty on the replacement water heater will be limited to the unexpired term of the original warranty.

2. ALL OTHER PARTS If within ONE year after initial installation of this water heater, any part or portion shall prove upon examination by the warrantor to be defective in material

or workmanship, the warrantor will repair or replace such part or portion at its option.

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, certied by A.G.A. and approved

by the American Society of Mechanical Engineers, must have been installed. a. This warranty shall apply only when the heater is: (1) owned by the original purchaser; (2) used at temperatures not exceeding the maximum setting of its thermostat; (3) used at water pressure not exceeding the working pressure shown on the heater; (4) (5) used when lled with potable water, free to circulate at all times; (6) used in a non-corrosive and non-contaminated atmosphere; (7) used with factory approved anode(s) installed; (8) in its original installation location; (9) in the United States, its territories or possessions, and Canada; (10) sized in accordance with proper sizing techniques for commercial water heaters; (11) bearing a rating plate which has not been altered, defaced or removed except as required by the warrantor; (12) red at the factory rated input using the fuel stated on the rating plate; (13) maintained in accordance with the instructions printed in the manual included with the heater. b. Any accident to the water heater, any misuse, abuse (including freezing) or alteration of it, any operation of it in a modied form, or any attempt to

c. This warranty is void if a device acting as a backow prevention device (check valves etc.) is installed in the cold water supply the heater is connected

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

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

c. All cost necessary or incidental for any material and/or permits required for installation of the replacement.

5. LIMITATIONS ON IMPLIED WARRANTIES

Implied warranties, including the warranty of merchantability imposed on the sale of this heater under state law are limited to one (1) year duration for the

6. CLAIM PROCEDURE Any claim under the warranty should be initiated with the dealer who sold the water heater, or with any other dealer handling the warrantor’s

U.S. Customers Canadian Customers A. O. Smith Corporation A. O. Smith Enterprises Ltd. 500 Tennessee Waltz Parkway P. O. Box, 310 - 768 Erie Street Ashland City, TN 37015 Stratford (Ontario) N5A 6T3 Telephone: 1-(800)-323-2636 Telephone: 1-(800) 265-8520 a. The warrantor will only honor replacement with identical or similar water heater or parts thereof which are manufactured or distributed by the warrantor. b. Dealer replacements are made subject to in-warranty validation by warrantor.

7. DISCLAIMERS

NO OTHER EXPRESS WARRANTY HAS BEEN OR WILL BE MADE IN BEHALF OF THE WARRANTOR WITH RESPECT TO THE MERCHANTABILITY

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 specic 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.

used when operated free of the damaging effects of uncontrolled water hammer;

repair tank leaks will void this warranty.

to, unless an effective method of controlling thermal expansion is also installed at the heater(s) and operational at all times.

costs may include but are not limited to:

the claimed defective heater or part to such distributor.

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.

products. If this is not practicable, the owner should contact:

OF THE HEATER OR THE INSTALLATION, OPERATION, REPAIR OR REPLACEMENT OF THE WATER HEATER. THE WARRANTOR SHALL NOT BE

RESPONSIBLE FOR WATER DAMAGE, LOSS OF USE OF THE UNIT, INCONVENIENCE, LOSS OR DAMAGE TO PERSONAL PROPERTY OR OTHER

CONSEQUENTIAL DAMAGE. THE WARRANTOR SHALL NOT BE LIABLE BY VIRTUE OF THIS WARRANTY OR OTHERWISE FOR DAMAGE TO ANY

PERSONS OR PROPERTY, WHETHER DIRECT OR INDIRECT, AND WHETHER ARISING IN CONTRACT OR TORT.

Date Installed________________________Model No.____________________________________________Serial No._________________________________________

Dealer’s Name _____________________________________________________________________Phone No.________________________________________________

Dealer’s Address__________________________________________________City and State________________________________________Zip Code________________

FILL IN WARRANTY AND KEEP FOR FUTURE REFERENCE.

Page 40

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A.O. Smith 500A User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual