A.O. Smith BTH 120 - 250 User Manual

CYCLONE XHE® Model BTH 120 - 250

COMMERCIAL GAS WATER HEATER

GAS-FIRED POWER BURNER

FOR DOMESTIC HOT WATER

 INSTALLATION  OPERATION  SERVICE  MAINTENANCE  LIMITED WARRANTY

WARNING: If the information in these

instructions is not followed exactly, a fire

or explosion may result causing property

damage, personal injury or death.

 Do not store or use gasoline or other

flammable vapors and liquids in the

vicinity of this or any other appliance.

 WHAT TO DO IF YOU SMELL GAS:

 Do not try to light any appliance.

 Do not touch any electrical switch;

do not use any phone in your

building.

 Immediately call your gas supplier

from a neighbor's phone. Follow the

gas supplier's instructions.

 If you cannot reach your gas supplier,

call the fire department.

 Installation and service must be

performed by a qualified installer,

service agency or the gas supplier.

Thank you for buying this energy efficient water heater from

A.O. Smith Water Products Company. We appreciate your

confidence in our products.

CAUTION

TEXT PRINTED OR OUTLINED IN RED CONTAINS

INFORMATION RELATIVE TO YOUR SAFETY. PLEASE

READ THOROUGHLY BEFORE INSTALLING AND USING

THIS APPLIANCE.

PLACE THESE INSTRUCTIONS ADJACENT TO HEATER AND

NOTIFY OWNER TO KEEP FOR FUTURE REFERENCE.

PRINTED IN U.S.A. 2570 1199 Part No. 194119-000

1

A DIVISION OF A.O. SMITH CORPORATION

Mc BEE, SOUTH CAROLINA

Supersedes P/Ns. 192968-000/193329-000/193311-000

ROUGH-IN -DIMENSIONS CYCLONE XHE BTH 120 - 250

Table 1. RECOVERY CAPACITIES - NATURAL GAS / L.P.

Model BTU Approx.

Input Gallon

Capacity 30 40 50 60 70 80 90 100 110 120 130 140

BTH - 120 125,000 Nat. 60 475 356 285 237 203 178 158 142 129 119 110 102

BTH - 120 120,000 L.P. 60 456 342 274 228 195 171 152 137 124 114 105 98

BTH - 150 150,000 Nat. 100 570 427 342 285 244 214 190 171 155 142 132 122

BTH - 150 150,000 L.P. 100 570 427 342 285 244 214 190 171 155 142 132 122

BTH - 199 199,900 Nat. 100 759 569 456 380 325 285 253 228 207 190 175 163

BTH - 199 199,900 L.P. 100 759 569 456 380 325 285 253 228 207 190 175 163

BTH - 250 240,000 Nat. 100 912 684 547 456 391 342 304 274 248 228 210 195

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

TEMPERATURE RISE - DEGREES °F - GALLONS PER HOUR

2

FOREWORD

These designs comply with the latest version of the American National

Standard for Gas Water Heaters, Volume III, ANSI Z21.10.3 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.

TABLE OF CONTENTS

PAGE

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

FOREWORD ....................................................................................... 3

FEATURES ........................................................................................... 4

Water Temperature Control ............................................................. 4

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

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

Circulating Pump ............................................................................. 5

INSTALLATION INSTRUCTIONS ......................................................... 5

Required Ability ............................................................................... 5

Insulation Blankets .......................................................................... 5

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

Clearances ...................................................................................... 6

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

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

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

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

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

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

VENTING ............................................................................................. 6

Vent Pipe Termination ..................................................................... 6

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

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

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

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

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

Installation of Vent System ............................................................ 10 -11

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

CONTROLS AND SWITCHES ............................................................. 11-12

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

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

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

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

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

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

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

Connection of Gas Pipe .................................................................. 13

Purging ............................................................................................ 13

Gas Meter Size - City Gases Only ................................................. 13

Gas Pressure Regulation ................................................................ 13

Gas Valves...................................................................................... 13

SYSTEM CONNECTIONS ................................................................... 13

Thermometers ................................................................................. 13

Relief Valve .................................................................................... 13

In addition to these instructions, the equipment shall be installed in

accordance with those installation regulations in force in the local area

where the installation is to be made. These shall be carefully followed in all

cases. Authorities having jurisdiction should be consulted before

installations are made.

In the absence of local codes, the installation must comply with the latest

editions of the National Fuel Gas Code, ANSI Z223.1/NFPA 54 and the

National Electric Code, NFPA 70. The former is available from the

Canadian Standards Association, 8501 East Pleasant Valley Road,

Cleveland, OH 44131, and both documents are available from the National

Fire Protection Association, 1 Batterymarch Park, Quincy, MA 02269.

PAGE

Water Line Connections .................................................................. 14

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

OPERATION ......................................................................................... 15

Sequence of Operation ................................................................... 15

Self Diagnostic Controller ............................................................... 15

Gas Value LEDs Flashing ............................................................... 15

Error Codes ..................................................................................... 16

Fault Conditions .............................................................................. 16

No Incoming Line Voltage ............................................................... 16

No Low Voltage ............................................................................... 16

Temperature Probe Fault ................................................................. 16

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

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

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

PRIOR TO START-UP .......................................................................... 18

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

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

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

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

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

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

GENERAL INFORMATION .................................................................... 20

Power Burner ................................................................................... 20

High Limit ........................................................................................ 20

High Altitude Installations ................................................................ 20

MAINTENANCE ..................................................................................... 20

General ............................................................................................ 20

Maintenance Schedule ..................................................................... 20

Flushing ........................................................................................... 21

Draining ........................................................................................... 21

Sediment Removal .......................................................................... 21

Lime Scale Removal ....................................................................... 21

Anode Inspection and Replacement ................................................ 21-22

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

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

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

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

INSTALLATION DIAGRAMS ................................................................... 23 - 27

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

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

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

REPLACEMENT PARTS ......................................................................... 30

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

3

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

Temperature Time to Produce 2nd & 3rd

Setting Degree Burns on Adult Skin

180°F Nearly instantaneous

170°F Nearly instantaneous

160°F About 1/2 second

150°F About 1-1/2 seconds

140°F Less than 5 seconds

130°F About 30 seconds

120°F More than 5 minutes

FIGURE 1

Valves for reducing point-of-use temperature by mixing cold and hot water

are available (see Figure 2). Also available are inexpensive devices that

attach to faucets to limit hot water temperatures. Contact a licensed plumber

or the local plumbing authority.

DANGER

THIS WATER HEATER IS EQUIPPED WITH AN ADJUSTABLE THERMOSTAT

TO CONTROL WATER TEMPERATURE. HOT WATER TEMPERATURES

REQUIRED FOR AUTOMATIC DISHWASHER AND LAUNDRY USE CAN

CAUSE SCALD BURNS RESULTING IN SERIOUS PERSONAL INJURY AND/

OR DEATH. THE TEMPERATURE AT WHICH INJURY OCCURS VARIES WITH

THE PERSONS AGE AND TIME OF EXPOSURE. THE SLOWER RESPONSE

TIME OF DISABLED PERSONS INCREASES THE HAZARDS TO THEM. NEVER

ALLOW SMALL CHILDREN TO USE A HOT WATER TAP, OR TO DRAW

THEIR OWN BATH WATER. NEVER LEAVE A CHILD OR DISABLED PERSON

UNATTENDED IN A BATHTUB OR SHOWER.

THE WATER HEATER SHOULD BE LOCATED IN AN AREA WHERE THE

GENERAL PUBLIC DOES NOT HAVE ACCESS TO SET TEMPERATURES.

The water temperature is controlled using the Temperature Control Button

on the Display at the front of the unit (See Figure 1). This control utilizes

two temperature probes to determine the tank temperature. The primary

temperature probe is located at the top of the tank and the other is near the

water inlet.

The temperature may be adjusted from 80° to 180°F. The thermostat was

adjusted to 120°F before the heater was shipped from the factory. It is

recommended that lower water temperatures be used to avoid the risk of

scalding. It is further recommended, in all cases, that the water temperature

be set for the lowest temperature which satisfies your hot water needs.

This will also provide the most energy efficient operation of the water

heater and minimize scale formation.

SETTING THE WATER HEATER TEMPERATURE AT 120°F WILL REDUCE THE

RISK OF SCALDS. Some states require settings at specific lower

temperatures.

Figure 1 shows the approximate time-to-burn relationship for normal adult

skin. Short repeated heating cycles caused by small hot water uses can

cause temperatures at the point of use to exceed the thermostat setting by

up to 20°F. If you experience this type of use, you should consider using

lower temperature settings to reduce scald hazards.

FIGURE 2

HIGH LIMIT SWITCH (E.C.O.)

The top immersion well of the dual bulb controller also contains the high limit

(energy cutoff) sensor. The high limit switch interrupts the main burner

gas flow should the water temperature reach approximately 202°F.

Should the high limit switch activate, it must be manually reset by depressing

the Temperature Adjustment Button/Reset Button on the display board. The

water temperature must drop below 160°F before the controller can be

reset.

Continued manual resetting of high limit control, preceded by higher than

usual water temperature is evidence of high limit switch operation. The

following are possible reasons for high limit switch operation.

 A malfunction in the thermostatic controls would allow the gas valve to

remain open causing water temperature to exceed the thermostat setting.

The water temperature would continue to rise until high limit switch

operation.

Contact your dealer or servicer if continued high limit switch operation

occurs.

4

DISHWASHING MACHINE REQUIREMENT

LOCATING THE HEATER

All dishwashing machines meeting the National Sanitation Foundation

requirements are designed to operate with water flow pressures between

15 and 25 pounds per square inch. Flow pressures above 25 pounds per

square inch, or below 15 pounds per square inch, will result in improperly

sanitized dishes. Where pressures are high, a water pressure reducing

or flow regulating control valve should be used in the 180°F 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

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 water at the point of

take-off to the dishwashing machine. Adjust flow by means of the plug

cock in the circulating line. (See installation diagrams.)

CIRCULATING PUMP

A circulating pump is used when a system requires a circulating loop or

there is a storage tank used in conjunction with the heater. Refer to the

piping diagrams at rear of manual for electrical hookup information and

install in accordance with the latest version of the National Electric Code

ANSI/NFPA No. 70.

Only all bronze circulators are 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

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 OR MORE ABOVE THE FLOOR.

THIS MAY REDUCE THE RISK IF LOCATION IN SUCH AN AREA CANNOT BE

AVOIDED.

THE HEATER SHALL BE LOCATED OR PROTECTED SO IT IS NOT SUBJECT

TO PHYSICAL DAMAGE BY A MOVING VEHICLE.

DO NOT LOCATE THE HEATER WHERE NOISE FROM THE EXHAUST OR

INTAKE WILL BE OBJECTIONABLE. THIS INCLUDES LOCATIONS CLOSE TO

OR ACROSS FROM WINDOWS AND DOORS. AVOID ANCHORING THE

VENT AND INTAKE PIPES DIRECTLY TO FRAMED WALLS, FLOORS OF

CEILINGS UNLESS RUBBER ISOLATION PIPE HANGERS ARE USED. THIS

PREVENTS ANY VIBRATIONS FROM BEING TRANSMITTED INTO THE LIVING

SPACES.

WARNING

FLAMMABLE ITEMS, PRESSURIZED CONTAINERS OR ANY OTHER

POTENTIAL FIRE HAZARDOUS ARTICLES MUST 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 termination

points as practicable, with adequate air supply and as centralized with the

piping system as possible.

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.

INSULATION BLANKETS

Insulation blankets available to the general public for external use on gas

water heaters are not approved for use on your A.O. Smith water heater.

The purpose of an insulation blanket is to reduce the standby heat loss

encountered with storage tank water heaters. Your A.O. Smith water

heater meets or exceeds the ASHRAE/IES 90.1b 1992 standards with

respect to insulation and standby loss requirements, making an insulation

blanket unnecessary.

WARNING

Should you choose to apply an insulation blanket to this heater, you should

follow these instructions. Failure to follow these instructions can result in

fire, asphyxiation, serious personal injury or death.

Do not apply insulation to the top, or the upper 15" of the water heater,



as this will interfere with safe operation.



Do not cover the temperature & pressure relief valve.

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 BUILD-UP WILL

BLOCK THE EXHAUST OUTLET, WHICH WILL CAUSE IMPROPER

OPERATION.

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



heater or nearby for future reference.



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

directly over the existing labels.

FIGURE 3

5

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.

CLEARANCES

These heaters are approved for installation on combustible flooring in an

alcove when the minimum clearances from any combustion construction

are followed as indicated in Figure 4.

UNCONFINED SPACE

In buildings of conventional frame, brick or stone construction, unconfined

spaces may provide adequate air for combustion and ventilation.

If the unconfined space is within a building of tight construction (buildings

using the following construction: weather stripping, heavy insulation,

caulking, vapor barrier, etc.), air for combustion and ventilation must be

obtained from outdoors. The installation instructions for confined spaces

in tightly constructed buildings must be followed to ensure adequate air

supply.

CONFINED SPACE

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" should be maintained from serviceable parts

such as relief valves, flue baffles, flue damper devices, thermostats,

cleanout openings or drain valves.

Always disconnect electrical power before servicing the unit

FIGURE 4

*ILLUSTRATION OF MINIMUM COMBUSTIBLE CLEARANCES IN AN

ALCOVE

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.

AIR REQUIREMENTS

KEEP APPLIANCE AREA CLEAR AND FREE OF COMBUSTIBLE MATERIALS,

GASOLINE AND OTHER FLAMMABLE VAPORS AND LIQUIDS.

DO NOT OBSTRUCT THE FLOW OF COMBUSTION AND VENTILATING AIR.

WARNING

FOR SAFE OPERATION PROVIDE ADEQUATE AIR FOR COMBUSTION AND

VENTILATION. AN INSUFFICIENT SUPPLY OF AIR WILL CAUSE

RECIRCULATION OF COMBUSTION PRODUCTS RESULTING IN

CONTAMINATION THAT MAY BE HAZARDOUS TO LIFE. SUCH A CONDITION

OFTEN WILL RESULT IN A YELLOW, LUMINOUS BURNER FLAME, CAUSING

CARBONING OR SOOTING OF THE COMBUSTION CHAMBER, BURNERS

AND FLUE TUBES AND CREATES A RISK OF ASPHYXIATION.

When drawing combustion air from inside a conventionally constructed

building to a confined space, such a space shall be provided with two

permanent openings, ONE IN OR WITHIN 12 INCHES OF THE ENCLOSURE

TOP AND ONE IN OR WITHIN 12 INCHES OF THE ENCLOSURE BOTTOM.

Each opening shall have a free area of at least one square inch per 1000

Btuh of the total input of all appliances in the enclosure, but not less than

100 square inches.

If the confined space is within a building of tight construction, air for

combustion and ventilation must be obtained from outdoors. When directly

communicating with the outdoors through vertical ducts, two permanent

openings, located in the above manner, shall be provided. Each opening

shall have a free area of not less than one square inch per 4000 Btuh 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 of the total input of all appliances in the enclosure.

CHEMICAL VAPOR CORROSION

WARNING

CORROSION OF THE FLUE WAYS AND VENT SYSTEM MAY OCCUR IF AIR

FOR COMBUSTION CONTAINS CERTAIN CHEMICAL VAPORS. SUCH

CORROSION MAY RESULT IN FAILURE AND RISK OF ASPHYXIATION.

Spray can propellants, cleaning solvents, refrigerator and air conditioning

refrigerants, swimming pool chemicals, calcium and sodium chloride, waxes,

and process chemicals are typical compounds which are potentially

corrosive.

PRODUCTS OF THIS SORT SHOULD NOT BE STORED NEAR THE HEATER.

ALSO, AIR WHICH IS BROUGHT IN CONTACT WITH THE HEATER SHOULD

NOT CONTAIN ANY OF THESE CHEMICALS. IF NECESSARY,

UNCONTAMINATED AIR SHOULD BE OBTAINED FROM REMOTE OR OUTSIDE

SOURCES.

VENTING

WARNING

THE INSTRUCTIONS IN THIS SECTION ON VENTING MUST BE FOLLOWED

TO AVOID CHOKED COMBUSTION OR RECIRCULATION OF FLUE GASES.

SUCH CONDITIONS CAUSE SOOTING OR RISKS OF FIRE AND

ASPHYXIATION.

Heater must be protected from freezing downdrafts during shutdown periods.

WARNING

NEVER OPERATE THE HEATER UNLESS IT IS VENTED TO THE OUTDOORS

AND HAS ADEQUATE AIR SUPPLY TO AVOID RISKS OF IMPROPER

OPERATION, FIRE, EXPLOSION OR ASPHYXIATION.

VENT PIPE TERMINATION

NOTE: Before installing venting, determine place of vent pipe termination.

See Figure 6 before proceeding.

MECHANICAL EXHAUSTING OF ROOM AIR

Where an exhaust fan is installed in the same room with a heater, sufficient

openings for air must be provided in the walls. UNDERSIZED OPENINGS

WILL CAUSE AIR TO BE DRAWN INTO THE ROOM THROUGH THE HEATERS

VENTING SYSTEM, CAUSING POOR COMBUSTION. SOOTING MAY RESULT

IN SERIOUS DAMAGE TO THE HEATER AND RISK OF FIRE OR EXPLOSION.

IT CAN ALSO CREATE A RISK OF ASPHYXIATION.

DO NOT TERMINATE THE VENTING WHERE NOISE FROM THE EXHAUST OR

CAUTION

INTAKE WILL BE OBJECTIONABLE. THIS INCLUDES LOCATIONS CLOSE TO

OR ACROSS FROM WINDOWS AND DOORS. AVOID ANCHORING THE

VENT AND INTAKE PIPES DIRECTLY TO FRAMED WALLS, FLOORS OR

CEILINGS UNLESS RUBBER ISOLATION PIPE HANGERS ARE USED. THIS

PREVENTS ANY VIBRATIONS FROM BEING TRANSMITTED INTO THE LIVING

SPACES.

6

DIRECT VENT

DO NOT TERMINATE EXHAUST

OVER PUBLIC AREA WHERE

CONDENSATE OR VAPOR CAN

CAUSE NUISANCE OR HAZARD.

FIGURE 5

HORIZONTAL VENT

*NOTE: BTH 250 USES TEE ON

AIR INTAKE TERMINAL

EXHAUST VENT HOOD MUST BE

LOCATED 1' MINIMUM FROM ANY

OPENING IN BUILDING.

FIGURE 6

7

IMPORTANT

The vent system must terminate so that proper clearances are maintained

as cited in local codes or the latest edition of the National Fuel Gas Code,

ANSI Z223.1,7.3.4e and 7.8a,b, as follows:

1. Do not terminate the exhaust vent terminal over public area where

condensate or vapor can cause nuisance or hazard.

2. For direct vent, the venting system shall terminate at least 1 foot below,

1 foot horizontally from or 1 foot above any door, window, or gravity air

inlet into building.

3. For horizontal the venting system shall terminate 4 foot below, 4 foot

horizontally from or 1 foot above any door, window, or gravity air inlet

into building.

4. The manufacturer also recommends the vent system terminations not

be installed closer than 3 feet from an inside corner of an L shaped

structure. And not less than 1 foot above grade or anticipated snow

level.

5. The vent termination shall not be mounted directly above or within 3 feet

horizontally from an oil tank vent or gas meter to avoid potential freeze-

up from condensation.

6. The vent shall terminate a minimum of 12" above expected snowfall

level to prevent blockage of vent termination.

Plan the vent system layout so that proper clearances are maintained from

plumbing and wiring.

Vent pipes serving power vented appliances are classified by building

codes as "vent connectors". Required clearances from combustible

materials must be provided in accordance with information in this manual

under LOCATION OF HEATER and CLEARANCES, and with National Fuel

Gas Code and local Codes.

IMPORTANT

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

the appliance.

WARNING

USE ONLY THE VENT TERMINALS SUPPLIED WITH THIS UNIT. TERMINATION

OF A VENT SYSTEM WITH A DEVICE OTHER THAN THE SUPPLIED VENT

TERMINATIONS WILL AFFECT SYSTEM PERFORMANCE AND RESULT IN A

SAFETY HAZARD.

FIGURE 8

DIRECT VENT TERMINAL INSTALLATION

IMPORTANT

THIS UNIT CONSISTS OF TWO VENT TERMINALS - AN INTAKE VENT

TERMINAL AND AN EXHAUST VENT TERMINAL. THE INTAKE VENT

TERMINAL IS A 3" 45°PVC ELBOW (OR 3" PVC TEE FOR BTH 250) WITH A

MESH WIRE SCREEN AND THE EXHAUST VENT TERMINAL IS A 3" 45°PVC

ELBOW WITH A MESH WIRE SCREEN.

BTH 120

BTH 150

& 199

DIRECT VENTING

The air intake provided on the unit contains a mesh screen (see Figure 7)

to prevent large particles from entering the unit.

3" 45° PVC ELBOW WITH MESH SCREEN

FIGURE 7

WARNING

WHEN THE UNIT IS TO BE SETUP AS A DIRECT VENT, THE MESH SCREEN

MUST BE REMOVED. THE INLET VENT PIPE MAY THEN BE GLUED TO THE

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

BTH 250

FIGURE 9

8

IMPORTANT

WHEN LOCATING THE TERMINALS ON A SIDEWALL, THE FOLLOWING

SPECIFICATIONS PERTAINING TO TERMINAL LOCATION MUST BE

FOLLOWED.

1. The intake vent terminal and the exhaust vent terminal must terminate on

the same exterior wall and must be located at a minimum of 24" (inches)

from the vertical centerline of the exhaust vent terminal (see Figure 9).

In colder climates increasing the 24" minimum will reduce possibility of

frost over from side winds blowing exhaust vapors to the air intake of

the direct the vent.

2. The horizontal centerline of the intake vent terminal may not be located

lower than the horizontal centerline of the exhaust vent terminal

(see Figure 9).

INSTALLATION SEQUENCE

For installations in the City of Los Angeles, California Category IV PVC Pipe

such as that manufactured by Brownline Pipe Company, must be used as

vent pipe material

CAUTION

Vent terminals supplied with the heater must be used.

NOTE: BEFORE BEGINNING INSTALLATION OF ANY VENT PIPE READ THE

VENT PIPE MANUFACTURER'S INSTALLATION INSTRUCTIONS.

1. After the points of termination have been determined, use the cover

plates as templates to mark the holes for the vent pipes to be inserted

through the wall. BEWARE OF CONCEALED WIRING AND PIPING INSIDE

OF WALL.

2. If the vent terminals are being installed on the outside of a finished wall,

it may be easier to mark both the inside and outside wall. Align the holes

by drilling a hole through the center of the template from the inside

through to the outside. The template can now be positioned on the

outside wall using the drilled holes as a centering point for the template.

3. A) MASONRY SIDE WALLS

Chisel an opening approximately one half inch larger than the marked

circle.

B) WOODEN SIDE WALLS

Drill a pilot hole approximately one quarter inch outside of the marked

circle. This pilot hole is used as a starting point for a saws-all or sabre

saw blade. Cut around the marked circle staying approximately one

quarter inch outside of the line. (This will allow the vent pipe to easily

slide through the opening. The resulting gap will be covered by the vent

terminal cover plates.) Repeat this step on the inside wall if necessary.

4. Cut a length of 3 inch PVC pipe about 3.5 inches longer than the wall

thickness at the opening.

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

6. Slide the wall plate over the pipe to stop against intake vent terminal.

7. Place a bead of caulking (not supplied) around the gap between the

pipe and the wall. Place some of the caulking on the back of the plate to

hold it against the wall after installation.

8. If the vent pipe is installed up to the wall, with a coupling on the end

against the wall opening, the pipe with the vent terminal can be prepared

for gluing before inserting through the wall. Slide the pipe through the

wall and insert into coupling on the other side of the wall, making sure

that the vent terminal ends up pointed in the correct position (Figure 10).

FIGURE 10

9

FIGURE 11

VERTICAL VENT TERMINAL INSTALLATION

IMPORT ANT

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

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

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

3. The intake vent termination and the exhaust vent termination must
penetrate the same side of roof.

4. The center line of the intake vent termination and the center line of the
exhaust vent termination must be no closer than 24" (inches).

5. The intake vent terminal and the exhaust vent terminal must be oriented
facing downward and the same direction.

The specifications are displayed in Figure 11 & 12.

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

INST ALLA TION SEQUENCE

NOTE: BEFORE BEGINNING INSTALLATION OF ANY VENT PIPE, READ
“VENT PIPE PREPARATION” SECTION ON PAGE 11.

1. After the points of termination have been determined, use the cover
plates as templates to mark the holes for the vent pipes to be inserted
through the roof.

2. Drill a pilot hole approximately one quarter inch outside of the marked
circle. This pilot hole is used as a star ting point for a saws-all or sabre
saw blade. Cut around the marked circle staying approximately one
quarter inch outside the line. (This will allow the vent pipe to easily slide
through the opening). The resulting gap will be covered by the roof boot/
flashing.

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

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

5. Seal around flashing.

6. Terminate intake terminal and exhaust vent terminal facing down as
shown in Figure 12.

FIGURE 12

INSTALLATION OF VENT SYSTEM

WARNING

THE OPTIONAL INTAKE VENTING ARRANGEMENT AND THE EXHAUST

VENTING ARRANGEMENT MUST BE 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. The installer may add up to a MAXIMUM OF FIFTY (50) EQUIVALENT

feet of pipe to the exhaust venting arrangement. This addition of FIFTY

(50) EQUIVALENT feet of pipe on both the intake venting arrangement

and exhaust venting arrangement must include any 3 inch PVC elbows

which equals (5) EQUIVALENT feet of pipe.

10

Table 2. VENT LENGTH TABLE

Number of 3" Minimum 3" Maximum 4" Maximum

90° Elbows Pipe (Feet) Pipe (Feet) Pipe (Feet)

ONE (1) 7 45 115

TWO (2) 7 40 110

THREE (3) 7 35 105

FOUR (4) 7 30 100

FIVE (5) 7 -- - 95

SIX (6) 7 -- - 90

4-inch PVC may be used for a MAXIMUM intake of ONE HUNDRED TWENTY

(120) EQUIVALENT FEET and a MAXIMUM exhaust of ONE HUNDRED

TWENTY (120) EQUIVALENT FEET. The maximum number of 90° elbows

with the 4-inch venting is six (6) on the intake and six (6) on the exhaust.

A 90° elbow is equal to five (5) equivalent feet of pipe. One (1) 90° elbow

is equal to two (2) 45° elbows. Any venting configuration using less than

50 equivalent feet should use 3-inch venting. See Table 2.

The 3-inch venting terminals (provided) must be used with the 4-inch

venting by adding 4x3 reducing couplings at the venting terminals. A

reducing coupling is also needed immediately after the condensate elbow

(exhaust) and immediately before the 3-inch blower adapter (intake) if

direct venting is installed. See Table 2.

IMPORTANT

When multiple units are direct vented through a wall (3-inch or 4-inch

venting), all intake vent terminals should be no lower than the highest

exhaust vent terminal.

NOTE: This unit can be vented using only PVC (Class 160, ASTM D-2241

Schedule 40, ASTM D-1785 ; or Cellular Core Schedule 40 DWV, ASTM

F-891) , Schedule 40 CPVC (ASTM F-411), or ABS (ASTM D-2661) pipe.

The fittings, other than the TERMINATIONS should be equivalent to PVC-

DWV fittings meeting ASTM D-2665 (Use CPVC fittings, ASTM F-438 for

CPVC pipe and ABS fittings, ASTM D-2661/3311 for ABS pipe. If CPVC or

ABS pipe and fittings are used, then the proper cement must be used for

all joints, including joining the pipe to the Termination (PVC Material). PVC

Materials should use ASTM D-2564 Grade Cement; CPVC Materials should

use ASTM F-493 Grade Cement and ; ABS Materials should use ASTM

D-2235 Grade Cement.

NOTE: for Water Heaters in locations with high ambient temperatures

(above 100°F) and/or insufficient dilution air, it is recommended that CPVC

or ABS pipe and fittings (MUST USE SUPPLIED VENT TERMINAL) be used.

D. Know your own qualifications or those of your contractor. The

solvent welding technique of joining PVC, PVC cellular core, ABS or

CPVC pipe is a specialized skill just as any other pipe fitting technique.

E. Closely supervise the installation and inspect the finished job before

start-up.

F. Contact the manufacturer, supplier, or competent consulting agency

if you have any questions about the application or installation of

PVC, PVC cellular core, ABS or CPVC pipe.

G. Take the time and effort to do a professional job. Shortcuts will only

cause you problems and delays in start-up. The majority of failures

in these systems are the result of shortcuts and/or improper joining

techniques.

2. SELECTION OF MATERIALS

PRIMER

It is recommended that Tetrahydrofuran (THF) be used to prepare the

surfaces of pipe and fittings for solvent welding. Do not use water, rags,

gasoline or any other substitutes for cleaning PVC cellular core, ABS or

CPVC surfaces. A chemical cleaner such as MEK may be used.

CEMENT

The cement should be a bodied cement of approximately 500 to 1600

centipoise viscosity containing 10-20% (by weight) virgin PVC material

solvated with tetrahydrofuran (THF). Small quantities of dimethyl formamide

(DMF) may be included to act as a retarding agent to extend curing time.

Select the proper cement; Schedule 40 cement should be used for Schedule

40 pipe. Never use all-purpose cements, commercial glues and adhesives

or ABS cement to join PVC or CPVC pipe and fittings.

SAFETY PRECAUTION: PRIMERS AND CEMENTS ARE EXTREMELY

FLAMMABLE AND MUST NOT BE STORED OR USED NEAR HEAT OR

OPEN FLAME. ALSO, USE ONLY IN A WELL-VENTILATED AREA.

CONTROLS AND SWITCHES

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

BTH 150 and 199 are provided with three pressure switches. These

switches are essential to the safe and proper operation of the unit. All

switches are wired in series. The controller is set up to shut the unit down

whenever there is a failure of any of the switches. It is important to

understand the purpose of each switch.

4. It is important that condensate not be allowed to buildup in the exhaust

vent pipe. To prevent this from happening the pipe should be installed

with a slight, 1/8 inch per five feet (5') of pipe maximum downward

slope.

5. The vent system should be supported every five feet (5') of vertical

run and every three feet (3') of horizontal run of vent pipe length.

NOTE: Stress levels in the pipe and fittings can be significantly increased

by improper installation. If rigid pipe clamps are used to hold the pipe in

place, or if the pipe cannot move freely through a wall penetration, the pipe

may be directly stressed, or high thermal stresses may be formed when

the pipe heats up and expands. Install accordingly to minimize such stresses.

VENT PIPE PREPARATION

1. INITIAL PREPARATION

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

for the specific application you are attempting.

B. Know the physical and chemical characteristics and limitations of

the PVC, PVC cellular core, ABS or CPVC piping materials that you

are about to use.

C. Know the reputation of your pipe and cement manufacturer and

their products.

FIGURE 13

BLOWER PROVER SWITCH

(SEE FIGURE 13)

The Blower Prover Switch is provided on the heater to verify that the fan

is operating. It is a positive pressure switch whose electrical contacts are

normally open. When the fan increases the pressure in the burner, the

pressure switch will allow the electrical contacts to close. The pressure

switch is connected to the burner tap by a piece of tygon tubing. This

11

tubing must be connected in order for the switch to change the electrical

contacts. The controller requires that the electrical contacts on this air flow

switch be open before it will allow the blower to come on.

BLOCKED OUTLET PROVER SWITCH

(SEE FIGURE 13)

The Blocked Outlet Prover Switch is set up to shut the unit off when a build-

up of positive pressure in the exhaust vent pipe occurs. This switch is a

positive pressure switch that requires an increase in pressure to change

the electrical contacts from normally closed to open. When this switch

prevents the unit from igniting, most likely the exhaust is blocked by some

means Check to see if the condensate is allowed to flow freely from the

exhaust elbow and for obstructions in the exhaust venting and exhaust

vent terminal. Also verify that there is no more than fifty equivalent feet of

three inch PVC vent pipe on the exhaust.

BLOCKED INLET PROVER SWITCH

(SEE FIGURE 13)

The Blocked Inlet Prover Switch is set up to shut the unit off when a 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 PVC flange connected to the inlet

of the blower. When this switch prevents the unit from igniting, most likely

the intake is blocked by some means. Check to see if there is no more than

fifty equivalent feet of three inch PVC vent pipe on the intake. Also verify

that the intake and intake vent terminal is free of obstructions that may

prevent air from entering the unit.

LOW GAS PRESSURE SWITCH

(SEE FIGURE 13)

The Low Gas Switch (LGS) is a single-pole, normally open pressure switch

that will close its contacts when a rising pressure of 5.0 in. W.C. is

encountered. The contacts will open when the pressure falls below the

fixed set point of 5.0 in. W.C. The LGS monitors the gas supply pressure to

the heater. If the gas supply falls below 5.0 in. W.C., the main burner is

extinguished (if heater is running) or the heater will not start up.

ON/OFF SWITCH

The ON/OFF Switch is a single-pole, single-throw rocker switch. This

switch provides 120V from the line source to the heater.

MAXIMUM CAPACITY OF PIPE

TABLE 3

IN CUBIC FEET OF GAS PER HOUR

(Based upon a Pressure Drop of 0.5 inch Water Column

and 0.6 Specific Gravity Gas and max. gas pressure of 0.5 psig)

Length NOMINAL IRON PIPE SIZES, INCHES

in Feet 1/2" 3/4" 1" 1 1/4" 1 1/2" 2" 2 1/2" 3" 4"

10 175 360 680 1,400 2,100 3,950 6,300 11,000 23,000

20 120 250 465 950 1,460 2,750 4,350 7,700 15,800

30 97 200 375 770 1,180 2,200 3,520 6,250 12,800

40 82 170 320 660 990 1,900 3,000 5,300 10,900

50 73 151 285 580 900 1,680 2,650 4,750 9,700

60 66 138 260 530 810 1,520 2,400 4,300 8,800

70 61 125 240 490 750 1,400 2,250 3,900 8,100

80 57 118 220 460 690 1,300 2,050 3,700 7,500

90 53 110 205 430 650 1,220 1,950 3,450 7,200

100 50 103 195 400 620 1,150 1,850 3,250 6,700

125 44 93 175 360 550 1,020 1,650 2,950 6,000

150 40 84 160 325 500 950 1,500 2,650 5,500

175 37 377 145 300 460 850 1,370 2,450 5,000

200 36 72 135 280 430 800 1,280 2,280 4,600

WARNING

THE HEATER IS NOT INTENDED FOR OPERATION AT HIGHER THAN 14.0"

WATER COLUMN (1/2 POUND PER SQUARE INCH) SUPPLY GAS PRESSURE.

HIGHER GAS SUPPLY PRESSURES REQUIRE SUPPLEMENTAL REDUCING

SERVICE REGULATION. EXPOSURE TO HIGHER GAS SUPPLY PRESSURE

MAY CAUSE DAMAGE TO THE GAS CONTROLS WHICH COULD RESULT IN

FIRE OR EXPLOSION. IF OVERPRESSURE HAS OCCURRED SUCH AS

THROUGH IMPROPER TESTING OF GAS LINES OR EMERGENCY

MALFUNCTION OF THE SUPPLY SYSTEM THE 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.

THE WATER HEATER IS POLARITY SENSITIVE. BEFORE APPLYING

ELECTRICITY TO THIS HEATER BE CERTAIN THAT SUPPLY NEUTRAL WIRE

TO GROUND CHECK INDICATES ZERO VOLTAGE.

CAUTION

HOT SURFACE IGNITER

The Hot Surface Igniter is a device that ignites the main burner by high

temperature (>1800°F). When 120VAC is applied to the igniter, sufficient

heat is generated to ignite the main burner. Although improvements have

been made to strengthen the igniter, it is still fragile and care must be taken

when handling the igniter to prevent breakage.

GAS PIPING

Contact your local gas service company to ensure that adequate gas

service is available and to review applicable installation codes for your

area.

Size the main gas line in accordance with Table 3. The figures shown are

for straight lengths of pipe at 0.5 in. W.C. pressure drop, which is considered

normal for low pressure systems Note that fittings such as elbows and

tees will add to the pipe pressure drop.

DO NOT USE FLEXIBLE GAS PIPING.

CAUTION

IT IS IMPORTANT TO GUARD AGAINST GAS VALVE FOULING FROM

CONTAMINANTS IN THE GAS WAYS. SUCH FOULING MAY CAUSE

IMPROPER OPERATION, FIRE OR EXPLOSION.

IF COPPER SUPPLY LINES ARE USED THEY MUST BE INTERNALLY TINNED

AND CERTIFIED FOR GAS SERVICE.

BEFORE ATTACHING THE GAS LINE BE SURE THAT ALL GAS PIPE IS

CLEAN ON THE INSIDE.

TO TRAP ANY DIRT OR FOREIGN MATERIAL IN THE GAS SUPPLY LINE, A

DIRT LEG (SOMETIMES CALLED A SEDIMENT 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.

FIGURE 14

12

CONNECTION OF GAS PIPE

1. When connecting gas pipe to unit, apply wrench to flange only. Note: Do

not use wrench on gas valve or gas bracket. See Figure 15.

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.

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.

FIGURE 15

The Gas Leak Test is performed as follows: Paint pipe connections upstream

of gas control with a rich soap and water solution to test for leaks before

operating main burner. Bubbles indicate gas leak. To stop leak, tighten pipe

connections. After piping connections are checked, turn on main burner.

With main burner in operation, paint pipe joints (including flanges), pilot gas

tubing connections and control inlet and outlet with rich soap and water

solution. Bubbles indicate gas leak. To stop leak, tighten flange screws,

joints and pipe connections. Replace part if leak cant be stopped.

To prevent damage, care must be taken not to apply too much torque when

attaching gas supply pipe to gas valve inlet.

Apply joint compounds (pipe dope) sparingly and only to the male threads

of pipe joints. Do not apply compound to the first two threads. Use compounds

resistant to the action of liquefied petroleum gases.

DISCONNECT THE APPLIANCE AND ITS MANUAL GAS SHUTOFF VALVE

FROM THE GAS SUPPLY PIPING SYSTEM DURING ANY SUPPLY PRESSURE

TESTING EXCEEDING 1/2 PSIG. GAS SUPPLY LINE MUST BE CAPPED WHEN

DISCONNECTED FROM THE HEATER. FOR TEST PRESSURES OF 1/2 PSIG

OR LESS, THE APPLIANCE NEED NOT BE DISCONNECTED, BUT MUST BE

ISOLATED FROM THE SUPPLY PRESSURE TEST BY CLOSING THE MANUAL

GAS SHUTOFF VALVE.

BEFORE PLACING THE HEATER IN OPERATION, CHECK FOR GAS LEAKAGE.

USE SOAP AND WATER SOLUTION OR OTHER MATERIAL ACCEPTABLE

FOR THE PURPOSE OF LOCATING GAS LEAKS. DO NOT USE MATCHES,

CANDLES, FLAME OR OTHER SOURCES OF IGNITION FOR THIS PURPOSE.

PURGING

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

entered.

CAUTION

PURGING SHOULD BE PERFORMED BY PERSONS EXPERIENCED IN THIS

GAS METER SIZE - CITY GASES ONLY

Be sure that the gas meter has sufficient capacity to supply the full rated

gas input of the water heater as well as the requirements of all other gas

fired equipment supplied by the meter. If the gas meter is too small, ask the

gas company to install a larger meter having adequate capacity.

GAS PRESSURE REGULATION

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

14.0" W.C. and a minimum as shown in Table 4: that is, for Natural Gas, 5.0"

W.C. for BTH 120 & 250 or 4.5" W.C. for BTH 150 & 199 or; for L.P. Gas,

11.0" W.C. The inlet gas pressure must not exceed the maximum value. A

service regulator should be installed within ten feet (10') of unit.

GAS VALVES

WARNING

SHOULD OVERHEATING OCCUR OR THE GAS SUPPLY FAIL TO SHUT OFF,

TURN OFF THE MANUAL GAS CONTROL VALVE TO THE APPLIANCE.

SYSTEM CONNECTIONS

The system installation must conform to these instructions and to the local

code authority having jurisdiction. Good practice requires that all heavy

piping be supported.

THERMOMETERS (Not Supplied)

Thermometers should be obtained and field installed as shown in the

installation diagrams.

Thermometers are installed in the system as a means of detecting the

temperature of the outlet water supply.

RELIEF VALVE

This heater is equipped with an approved temperature and pressure relief

valve. ASME ratings cover pressure relief. A.G.A. ratings cover release

rate with temperature actuation.

FOR SAFE OPERATION OF THE WATER HEATER, THE RELIEF VALVE(S)

MUST NOT BE REMOVED OR PLUGGED.

In addition to the appliance relief valve, each remote storage tank which

may be used in conjunction with this appliance shall also be installed with

a properly sized, rated and approved temperature (ANSI) and pressure

(ASME) relief valve(s). This relief valve shall comply with the standard for

relief valves and automatic gas shutoff devices for hot water supply

systems. ANSI Z21.22

Your local code authority may have other specific relief valve requirements.

WARNING

THE PURPOSE OF A RELIEF VALVE IS TO AVOID EXCESSIVE PRESSURE

OR TEMPERATURE INTO THE STEAM RANGE, WHICH MAY CAUSE

SCALDING AT FIXTURES, TANK EXPLOSION, SYSTEM OR HEATER

DAMAGE. NO VALVE IS TO BE PLACED BETWEEN THE RELIEF VALVE AND

THE TANK.

A DRAIN LINE MUST BE CONNECTED TO THE RELIEF VALVE TO DIRECT

DISCHARGE TO A SAFE LOCATION TO AVOID SCALDING OR WATER

DAMAGE. THIS LINE MUST NOT BE 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.

13

WATER LINE CONNECTIONS

HEATER WIRING

This manual provides detailed installation diagrams (see back section of

this manual) for typical methods of application for the water heaters.

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

tank. When used with a separate storage tank, the circulation may be

either by gravity or by means of circulating pump. When a circulating pump

is used, it is important to note that the flow rate should be slow so that there

will be a minimum of turbulence inside the heater.

CLOSED SYSTEM

A closed system will exist if a check valve (without bypass), pressure

reducing valve (without bypass), or a water meter (without bypass) is

installed in the cold water line between the water heater and street main

(or well).

Excessive pressure may develop causing premature tank failure or

intermittent relief valve operation. This type of failure is not covered by the

limited warranty. An expansion tank or a similar device may be required in

the inlet supply line between the appliance and the meter or valve to

compensate for the thermal expansion of water under supply pressure.

If a water heater is installed in a closed water system, check local codes

or contact the water supplier or local plumbing inspector on how to control

this situation.

CAUTION

IF ANY OF THE ORIGINAL WIRE AS SUPPLIED WITH THE APPLIANCE

MUST BE REPLACED, IT MUST BE REPLACED WITH 105°C WIRE OR ITS

EQUIVALENT, EXCEPT IN THE BURNER HOUSING. IN THIS CASE USE

200°C WIRE.

THE COMPUTER CONTROL REQUIRES A SOURCE OF STABLE CLEAN

ELECTRICITY FOR PROPER OPERATION. INSTALLING THE HEATER ON

A BRANCH CIRCUIT THAT HAS ELECTRONIC NOISE, IS SUBJECT TO

FLUCTUATIONS IN VOLTAGE LEVEL OR HAS AN APPLIANCE WHICH

GENERATES EMF OF RFI INTERFERENCE CAN CAUSE THE

CONTROLLER TO MALFUNCTION. A HIGH QUALITY POWER

CONDITIONER MUST BE INSTALLED IF THE ABOVE CONDITIONS EXIST.

MALFUNCTIONS CAUSED BY A POOR ELECTRICAL SUPPLY ARE NOT

COVERED UNDER YOUR WARRANTY.

The controller is wired to the heater as shown in figures 16 & 17. The

model and rating plate provides the electrical information needed to

size the complete heater branch supply.

All electrical work must be installed in accordance with the National

Electrical Code and local requirements.

When installed, the appliance must be electrically grounded in

accordance with local codes or, in the absence of local codes, with

the National Electrical Code, ANSI/NFPA 70.

DO NOT ENERGIZE THE BRANCH CIRCUIT BEFORE THE HEATER TANK

IS FILLED WITH WATER.

NOTE: This controller is Polarity Sensitive. If the Hot and Neutral Supply

Voltage is reversed, the controller will not sense flame. Verify polarity

before connecting the unit.

BSR BOARD (BTH - 250 ONLY)

FIGURE 16

14

8. After an additional 2 seconds, the control will monitor the flame sense

probe to confirm a flame is present. If a flame is not verified within this

time period, the gas valve will immediately be closed, and the blower will

continue to run for approximately 10 seconds. The control will then

return to step 2.

9. If a flame is confirmed, the control will enter the heating mode where it

will continue heating the tank water until the setpoint temperature plus

differential is reached. At this point, the gas valve is closed and the

control enters the post-purge cycle.

10.The combustion blower will run for the duration of the post purge cycle

to purge the system of all combustion gases. When the post purge

cycle is complete, the blower is de-energized and will coast to a stop.

11. The control will now enter the idle state while continuing to monitor the

internal tank water temperature and the state of other system devices.

If the temperature drops below the setpoint value less differential, the

control will automatically return to step 2 and repeat the entire operating

cycle. During this idle state, if the control detects an improper operating

state for external devices such as the ECO switch, vent switch, pressure

switch, etc., the appropriate LED(s) on the Display Board will be

illuminated indicating the nature of the fault.

SELF DIAGNOSTIC CONTROLLER

ITEM DESCRIPTION

1. Transformer

2. Control Board

3. E.C.O./Temperature Probe

4. Blower Proving Air Switch

5. Low Voltage Cable Assembly

6. Line Voltage Cable Assembly

7. Blower/Motor Assembly

8. Igniter Assembly

9. Cable To Control Display Board

10. Control Display Board

11. Blocked Outlet Exhaust Switch

12. Lower Temperature Probe

13. Wire Assembly-Gas Pressure

Switch

FIGURE 17

14. Tubing-Pressure

15. Tubing-Pressure

16. Connector-Tubing

17. Switch-On/Off

18. Low Gas Pressure

Switch

19. Bocked Inlet Switch

20. Wire Assembly-Air

Flow Switch

OPERATION

SEQUENCE OF OPERATION

Typical Control/Appliance Operating Sequence

1. When the control is powered, it should first display 0, then the input

line voltage (120), the calibration setting (12), then the actual water

temperature in the tank.

2. If the control determines that the actual water temperature inside the

tank is below the programmed temperature setpoint less the differential,

a call for heat is activated.

3. The control then performs selected system diagnostic checks. This

includes confirming the proper state of the air switch 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.

This controller is designed for ignition lockout after three consecutive failed

attempts to light. If lockout occurs, the display lights will match Figure 18.

Along with this, a numeric message will appear in the display. The following

list of ERROR CODES illustrates possible numeric failures.

FIGURE 18

GAS VALVE LED FLASHING

This condition results from a failure to establish burner ignition after three

successive trials. In such cases:

1. Investigate the possible cause and remedy any observations.

2. Momentarily depress the button on the display panel to reset the lockout

condition.

3. Confirm proper appliance operation.

Possible Cause Remedy

1. Burner ground wire broken 1. Check wire and connection

or corroded at burner

2. Connectors unplugged 2. Check connections

3. Igniter broken 3. Replace igniter

4. Flame probe faulty 4. Replace flame probe

5. Gas shut off 5. Turn on gas supply

6. Clogged gas valve 6. Replace gas valve

7. Faulty gas valve 7. Replace gas valve

8. Defective control 8. Replace control

9. Burner improperly adjusted 9. Adjust burner

10. Dirty burner 10. Clean burner

15

ERROR CODES

The following Error Codes are external to the controller.

01 Pressure Switch Fail On, should be Off

11 Pressure Switch Fail Off, should be On

02 Ignition Fail after 3 attempts

04 ECO Open

05 Temperature Probe Open

15 Temperature Out of Bounds < 30 degrees

25 Temperature Out of Bounds > 220 degrees

The following Error Codes are internal to the controller.

113 Flame On Should be Off Fail

22 Ignition Relay Fail is On, should be Off

112 Ignition Relay Fail is Off, should be On

101 K2 Fail in K1

102 Main Loop Fail in K2

103 K1 Fail in Main Loop

Gas Valve Power Supply. (*WDPS Watch Dog Power Supply).

106 WDPS Fail to be Off

107 WDPS Fail to be Off

108 WDPS Fail to be On

116 Gas Valve Relay Fail is off, should be On

117 Gas Valve Relay Fail is On, should be Off

Checks The ROM (Read Only Memory).

200 CRC Check Sum Error

Checks The CPU (Central Processing Unit).

201 CPU Instruction Test Error

202 CPU Instruction Test Error

203 CPU Instruction Test Error

Possible Cause Remedy

1. No Input Power 1. Apply Power

2. Wiring Disconnected 2. Check all wiring

3. One or more wiring receptacles 3. Reconnect plugs on control,

disconnected from control confirm all are fully seated

4. LED burned out 4. Ignore or replace control

NO LOW VOLTAGE (Figure 20)

24V AC LED Off

Checks the RAM (Random Acess Memory).

205 RAM Test Fail

SW Check to see what the Last State it was in.

ie., Fails if it can from the wrong place

125 State Error

126 State Error

128 State Error

127 State Error

129 State Error

131 State Error

132 State Error

These State Numbers are not used.

230 Executed State 3 (Not Implimented) h.s.

240 Executed State 4 (Not Implimented) h.s

210 Executed State 10 (Not Implimented) h.s.

213 Executed State 13 (Not Implimented) h.s.

214 Executed State 14 (Not Implimented) h.s.

216 Executed State 16 (Not Implimented) h.s.

FAULT CONDITIONS

The controller is set up to provide additional status indicators under Fault

Conditons. The following figures are possible Fault Conditions.

NO INCOMING LINE VOLTAGE (Figure 19)

Line LED Off

NO LOW VOLTAGE, 24V AC LED Off

FIGURE 20

NOTE: The transformer is of Class II variety and has an internal non-

replaceable fuse. If blown, a problem may exist with the control which is

affecting the transformer. In such cases, the control should be replaced as

well.

Possible Cause Remedy

1. Transformer wiring problem 1. Repair Wiring

2. Defective Transformer 2. Replace Transformer

3. LED burned out 3. Ignore or replace control

TEMPERATURE PROBE FAULT (Figure 21)

Water Temp LED Flashing

NO INCOMING LINE VOLTAGE, Line LED Off

FIGURE 19

TEMPERATURE PROBE FAULT, Water Temp LED Flashing

FIGURE 21

This condition accommodates multiple failure modes. To more accurately

determine the cause of failure, press the pushbutton on the display board.

16

Display Flashes 05 when button is pressed:

Possible Cause Remedy

1. Temperature Probe wiring 1. Repair Wiring

open

2. Defective probe 2. Replace probe

Display Flashes 15 when button is pressed:

Possible Cause Remedy

1. No water in tank and tank 1. The symptom does not

in freezing conditions reflect a control problem

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

tolerance, replace temp.

probe

Display Flashes 25 when button is pressed:

Possible Cause Remedy

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

immersed in steam

2. Probe wiring shorted 2. Repair wiring

3. Defective probe 3. Replace probe

ECO SWITCH OPEN (Figure 22)

ECO LED Flashing:

CONTROL BAD, All LEDs Flashing

FIGURE 23

Possible Cause Remedy

1. Temp. Probe unplugged 1. Check connectors

2. Temp. probe wiring damaged 2. Repair wiring

3. Water in tank too hot 3. Normal condition when

water temperature

exceeds safety limit.

Allow water to cool or

admit water into tank and

manually reset the control.

Determine cause for

overtemp condition.

COMBUSTION AIR BLOCKAGE (Figure 24)

Pressure Switch LED Flashing:

ECO SWITCH OPEN, ECO LED Flashing

FIGURE 22

Possible Cause Remedy

1. This indicates the control has 1. Press button on the

failed on of its internal display board to reset

diagnostic self-tests. control. If this error

occurs repeatedly,

replace control.

CONTROL BAD (Figure 23)

All LEDs Flashing:

COMBUSTION AIR BLOCKAGE, Pressure Switch LED Flashing

FIGURE 24

Possible Cause Remedy

1. Combustion air blocked 1. Check exhaust piping and

flue for obstructions

2. Blower not operating: 2. a. Repair wiring

a. Check blower wiring b. Replace blower motor

b. Check blower motor

3. Defective air switch 3. Replace air switch

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

an open contact on the

blower proving airflow

switch before the blower

comes on. Check to see if

blower proving airflow

switch is still connected to

the unit.

17

PRIOR TO START UP

REQUIRED ABILITY

ADJUSTMENT PROCEDURE

INITIAL START-UP

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 specific heater
being used.

The power burner is equipped with an ignition system which automatically

sequences prepurge and ignition, senses and ignites main burner flame

and sequences burner operation. Heater is equipped with an ignition control

which locks out after three unsuccessful ignition attempts. Familiarize

yourself with the sequence of operation of this unit prior to start-up.

Be certain that the water heater is full of water, that air is purged from all

lines, there are no leaks (gas and water), and all inlet water lines are open.

The following test equipment should be on hand (all test equipment must be

acclimated to ambient temperature before calibration and use.)

 Two U-tube manometers or calibration 0-10" and 0-35" W.C. pressure

gauges.

 Attach a gas pressure gauge or manometer to the upstream side of

main gas cock and a gas pressure gauge or manometer to the manifold

pressure tap (see Figure 15).

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

OPERATING INSTRUCTIONS

IMPORTANT

IT IS RECOMMENDED THAT A QUALIFIED SERVICE TECHNICIAN PERFORM

THE INITIAL FIRING OF THE HEATER. AT THIS TIME THE USER SHOULD ASK

THE TECHNICIAN ANY QUESTIONS IN REGARD TO THE OPERATION AND

MAINTENANCE OF THE UNIT.

CAUTION

BEFORE PROCEEDING WITH THE OPERATION OF THE UNIT, MAKE SURE

HEATER AND SYSTEM ARE FILLED WITH WATER AND ALL AIR IS EXPELLED

FROM HEATER AND PIPING.

NEVER OPERATE THE HEATER WITHOUT FIRST BEING CER TAIN IT IS FILLED

WITH WATER AND A TEMPERATURE AND A PRESSURE RELIEF VALVE IS

INSTALLED IN THE RELIEF VALVEOPENING OF THE HEATER. DO NOT

ATTEMPT TO OPERATE HEATER WITH COLD WATER INLET VALVE CLOSED.

FILLING:

1. Close the heater drain valve.

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

escape.

3. Fully open the cold water inlet pipe valve allowing the heater and

piping to be filled.

4. Close the hot water faucet as water starts to flow.

5. The heater is ready to be operated.

THE MAIN MANUAL GAS SHUTOFF VALVE MUST HAVE BEEN CLOSED

FOR AT LEAST FIVE (5) MINUTES. THIS WAITING PERIOD IS AN IMPORTANT

SAFETY STEP. ITS PURPOSE IS TO PERMIT GAS THAT MIGHT HAVE

ACCUMULATED IN THE COMBUSTION CHAMBER TO CLEAR. IF YOU DETECT

GAS AT THE END OF THIS PERIOD, DO NOT PROCEED WITH LIGHTING.

RECOGNIZE THAT GAS ODOR, EVEN IF IT SEEMS WEAK, MAY INDICATE

THE PRESENCE OF ACCUMULATED GAS SOMEPLACE IN THE AREA WITH

A RISK OF FIRE OR EXPLOSION. SEE THE FRONT PAGE FOR STEPS TO BE

TAKEN.

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 ON PAGE 20 IN THIS MANUAL.

A minimum gas supply pressure of 5.0" W.C. (4.5" on BTH 150 and 199) for

natural gas (11.0" W.C. for L.P. Gas) is required before making any

adjustment to the gas control pressure regulator Attempts to adjust the

regulator during periods of low gas supply pressure could result in overfiring

of the heater when the gas supply pressure returns to normal.

1. Check gas line pressure with a manometer.

2. Check manifold pressure (see Table 4, page 20) using a pressure

gauge (manometer) connected to the manifold pressure tap on the

gas control valve, (Figure15).

If full rate adjustment is required, remove cover screw from top of the

gas control valve, (Figure 15).

Using a small screwdriver, turn adjusting screw clockwise to increase

or counterclockwise to decrease gas pressure to obtain 4.0" on

BTH 120 and 250 (3.5" on BTH 150 and 199) for natural gas (10.0" W.C.

for L.P. Gas) Water Column.

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

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

5. Check the vent system seams and joints and ensure that there is no

discharge of flue products into the room.

6. Check the input rate:

For appliance installation locations with elevations above 2000 feet, refer

to HIGH ALTITUDE INSTALLATIONS section of this manual.

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

(Figure 16) and refer to Table 4, page 20 for correct pressure.

b. Use this formula to clock the meter. Be sure other gas consuming

appliances are not operating during this interval.

3600

X H = Btuh

T

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

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

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

the gas meter and measure the amount of time required for the

heater to consume 1 cubic foot of gas.)

H = Heating value of gas (in Btus per cubic foot of gas).

Btuh = Actual heater input rate, in Btuh.

EXAMPLE: (Using BTH-199,900 heater)

T = 18.9 seconds

H = 1050 Btu/ft.

BTUH = ?

For high altitude installations, compare result to the derated input

required for the elevation at the installation location.

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

the pressure by turning the adjusting screw with a small

screwdriver. Do not exceed 4.0" on BTH 120 and 250 (3.5" on BTH

150 and 199) Water Column.

Clockwise to increase gas pressure and input rate.

Counterclockwise to decrease gas pressure and input rate.

d. Clock the meter as in step (b) above.

e. Repeat steps (c) and (d) until the specified input rate is achieved.

f. Turn the manual gas valve to OFF. Replace the pressure regulator

cover screw. Remove the pressure gauge or manometer from the

manifold pressure tap. Replace the set screw in the manifold pressure

tap. If the gas pressure regulator cannot be adjusted to give the full

input rating with sufficient gas pressure at the valve, check to ensure

the unit is equipped with the correct orifice.

3

3600

X 1050 = 199,900 Btuh

18.9

18

FOR YOUR SAFETY READ BEFORE OPERATING

WARNING:

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

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

19

HIGH ALTITUDE INSTALLATIONS

UNDER NO CIRCUMSTANCES SHOULD THE INPUT EXCEED THE RATE

WARNING

SHOWN ON THE HEATER RATING PLATE. OVERFIRING COULD RESULT IN

DAMAGE OR SOOTING OF THE HEATER.

CATHODIC PROTECTION

CAUTION

HYDROGEN GAS CAN BE PRODUCED IN A HOT WATER SYSTEM SERVED

BY THIS HEATER THAT HAS NOT BEEN USED FOR A LONG PERIOD OF

TIME (GENERALLY TWO WEEKS OR MORE). HYDROGEN GAS IS

EXTREMELY FLAMMABLE. To reduce the risk of injury under these

conditions, it is recommended that a hot water faucet be opened for several

minutes before using any electrical appliance connected to the hot water

system. If hydrogen is present, there will probably be an unusual sound

such as air escaping through the pipe as the water begins to flow. There

should be no smoking or open flame near the faucet at the time it is open.

PRECAUTIONS

IF THE UNIT IS EXPOSED TO THE FOLLOWING, DO NOT OPERATE HEATER

UNTIL ALL CORRECTIVE STEPS HAVE BEEN MADE BY A QUALIFIED

SERVICEMAN.

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

2. EXTERNAL FIRING

3. DAMAGE

4. FIRING WITHOUT WATER

5. SOOTING

WARNING

BTH HEATERS ARE CERTIFIED FOR USE WITHOUT MODIFICATION FOR

ALTITUDES UP TO 6500 FEET. INSTALLATIONS ABOVE 6500 FEET MAY

REQUIRE REPLACEMENT OF THE BURNER ORIFICE. CALL THE TECHNICAL

CENTER @ [phone] FOR REQUIREMENTS.

Some gas utility companies derate their gas for altitude, making it

unneccessary to install high altitude orifices. Call the local gas or utlity

company to verify BTU content.

Due to the input rating reduction at high altitudes, the output rating of the

appliance is also reduced and should be compensated for in the sizing of

the equipment for applications.

MAINTENANCE

GENERAL

KEEP APPLIANCE AREA CLEAR AND FREE FROM COMBUSTIBLE

MATERIALS, GASOLINE AND OTHER FLAMMABLE VAPORS AND LIQUIDS.

(SEE WARNING ON PAGE 5, LOCATING THE HEATER).

Water heater maintenance includes periodic tank flushing and cleaning,

and removal of lime scale. The unit should be inspected and adjusted to

maintain proper combustion. Refer to the following table. A periodic

inspection of the venting system should be made. Where used, the water

circulating pump should be oiled.

NEVER OPERATE THE HEATER WITHOUT FIRST BEING CERTAIN IT IS FILLED

WITH WATER AND A TEMPERATURE AND PRESSURE RELIEF VALVE IS

INSTALLED IN THE RELIEF VALVE OPENING OF THE HEATER.

SHOULD OVERHEATING OCCUR OR THE GAS SUPPLY FAIL 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 18.

The sequence of operation of the unit is provided on page 15.

It is important to note that the controller has a reset button on the control

box, Figure 1. The reset button is a safety device and would not normally

be used.

HIGH LIMIT

The high limit (not adjustable) is factory set to cutout at 202°F. The controller

must be manually reset by depressing the reset button on front of the

control when water temperature drops to below 160°F.

TABLE 4

GAS SUPPLY SPECIFICATIONS

Max. Gas Supply Press. W.C. 14.0 14.0 14.0

Nominal Gas Supply Press. W.C 7.0 7.0 11.0

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

Manifold Press. W.C. 4.0 3.5 10.0

BTH 120 BTH 150 BTH 120

& 250 & 199 150 & 199

Natural Gas Natural Gas L.P. Gas

MAINTENANCE SCHEDULE

Following are the instructions for performing some of the recommended

maintenance. Unit inspection and adjustment should be performed by a

competent technician.

COMPONENT OPERATION INTERVAL REQUIRED

Tank Sediment Monthly Flushing

Removal

Tank Lime Scale Semi UN-LIME

Removal Annually Delimer

Anode Inspect Semi Replace as

Rods Annually Required

Relief Valve Inspect Semi

Annually

SAE No. 20

Circulating Oiling Four Months non-detergent

Pump (1) motor oil

Clean Inlet

Blower Screen and As Required Soft Brush

Blower Wheel

Vent System Inspect Every 3 Joints should

Months be sealed

(1) If furnished with oiling provision.

®

20

FLUSHING

1. Turn off the heater electrical disconnect switch.

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

3. Close the drain valve when finished flushing.

4. Turn on the heater electrical disconnect switch.

DRAINING

The heater must be drained if it is to be shut down and exposed to

freezing temperatures. Maintenance and service procedures may also

require draining the heater.

1. Turn off the heater electrical disconnect switch.

2. Close the cold water inlet valve to heater.

3. Open a nearby hot water faucet to vent the system.

4. Open the heater drain valve.

FIGURE 25

To dissolve and remove the more stubborn mineral deposits, A.O. Smith

UNLIME® Professional Delimer should be used.

5. If the heater is being drained for an extended shutdown, it is suggested

the drain valve be left open during this period.

 Follow FILLING instructions when restoring hot water service.

SEDIMENT 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 efficiency of the heater and increases fuel consumption.

The usage of water softening equipment greatly reduces the hardness

of the water. However, this equipment does not always remove all of the

hardness (lime). For this reason it is recommended that a regular schedule

for deliming be maintained.

The depth of lime buildup should be measured periodically. Heaters will

have about 3" of lime buildup when the level of lime has reached the

bottom of the cleanout opening or about 1" 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" buildup of lime.

Example 1:

Initial inspection shows 1/2" of lime accumulation. Therefore, the heater

can be delimed once a year.

Example 2 :

Initial inspection shows 2" of lime accumulation. Therefore, the heater

should be delimed every 3 months.

Sediment and lime scale removal may be accomplished through the

cleanout opening furnished on the heater, see Figure 25. The heater must

be drained, see DRAINING, before removing cleanout cover on tank.

A.O. Smith UNLIME® Professional Delimer is an easy to handle patented

food grade acid formulated specifically for lime scale removal from all

types of water using equipment. Available in 1 gallon (part no. 4763) and

5 gallon (part no. 4813) sizes. Hydrochloric base acids are not

recommended for use on glass-lined tanks.

A.O. Smith Form No. 4800, entitled Why, When and How, describes tank

cleaning methods and materials. UNLIME and the booklet may be obtained

through your A.O. Smith dealer or distributor.

The cleanout opening is shown in Figure 25. To clean heater through

cleanout opening, proceed as follow:

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

open drain valve.

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

3. Remove cover from cleanout opening.

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

glass-lining.

5. Inspect cleanout plate gasket: If new gasket is required, replace with

A. O. Smith part no. 99038.

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

screws securely.

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

electrical disconnect switch.

8. Check for water leakage.

9. Replace outer jacket cover plate.

ANODE INSPECTION AND REPLACEMENT

This water heater is equipped with multiple sacrificial anodes. Anodes

protect the glass-lined tank from corrosion by sacrificing themselves

through electrolysis. When the anode material is consumed, there is no

more protection and corrosion of the tank accelerates

Inspection of the anode every 6 to 12 months allows you to identify a

spent anode and replace it. Replace the anode when its diameter is 3/8"

of an inch, or annually which ever is first. Aggressive, very hot and

softened water causes rapid consumption of the anode requiring frequent

inspections. Anodes are available from your distributor or A.O. Smith.

21

To inspect or replace an anode:

The anodes on this heater are easily accessible from the top of the

heater making replacement simple and quick.

1. Turn the heater off per the lighting instructions. Connect a hose to the

drain valve . Locate the hose's discharge in an area where hot water

will not cause any damage or injury.

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

heater.

BEFORE MANUALLY OPERATING THE VALVE, MAKE SURE THAT A DRAIN

CAUTION

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.

If the temperature and pressure relief valve on the heater discharges

periodically or continuously, it may be due to thermal expansion of water in

a closed water supply system, or, it may be due to a faulty relief valve.

3. Shut off the cold water supply. Make sure all hot water fixtures and

circulating pumps are turned off.

4. Wait for water flow from the hose to stop. Remove the anode using a

socket of the appropriate size Sometimes a pry bar will be required to

loosen the anode plug . Do not use an impact wrench.

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

when reinstalling the anode.

6. Close the drain valve . Open a hot water fixture to allow air to escape.

Open the cold water supply to heater and allow the tank to fill. Follow

the lighting instructions.

7. Check your anode and drain valve for leaks.

DRAIN VALVE AND ACCESS PANELS

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

An access panel covers the cleanout opening in the tank which is sealed

by a gasket and cover, figure 25.

RELIEF 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 flow, remove and inspect for obstructions or corrosion.

Replace with a new valve of the recommended size as necessary.

Inspection of the valve should be performed at least every three years. Do

not attempt to repair the valve, as this could result in improper operation

and a tank explosion. In areas with poor water conditions, it may be

necessary to inspect the T&P valve more often than every three years.

Thermal expansion is the normal response of water when it is heated. In

a closed system, thermal expansion will cause the system pressure to

build until the relief valve actuation pressure is equaled. Then, the relief

valve will open, allowing some water to escape, slightly lowering the

pressure.

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

this situation.

Two common corrections are listed in the Checklist and Service Information

which appears later in this manual.

ABOVE ALL, DO NOT PLUG THE TEMPERATURE AND PRESSURE RELIEF

VALVE. THIS IS NOT A SOLUTION AND CAN CREATE A HAZARDOUS

SITUATION.

CIRCULATING PUMP

The water heating system may include a circulating pump. Where used, it

should be lubricated as directed by the circulator manufacturer.

VENT SYSTEM

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

follows:

1. Check for obstructions and/or deterioration of vent piping and vent

hood. Replace immediately where needed.

2. Vent pipe and vent hood screen should be cleaned of foreign material

and soot. The screen is located inside the vent hood outlet and is

accessible from the outside of the hood. Do not reach inside the vent

hood when the heater is in operation.

3. Check all vent system connections for leakage and reseal as required

using Hi Temp Silicone sealer or equivalent.

22

INSTALLATION DIAGRAMS

ONE TEMPERATURE - ONE HEATER VERTICAL STORAGE TANK FORCED CIRCULATION

WITH OR WITHOUT BUILDING RECIRCULATION

CAUTION: IF BUILDING COLD

WATER SUPPLY HAS A BACK-

FLOW PREVENTER, CHECK

VALVE OR WATER METER WITH

CHECK VALVE PROVISIONS

FOR THERMAL EXPANSION OF

WATER IN THE HOT WATER

SYSTEM MUST BE PROVIDED

NOTE: CONNECT RETURN

LINE FROM HOT WATER

CIRCULATING LOOP (IF USED)

TO COLD WATER INLET LINE.

* PIPE TO OPEN DRAIN

INST ALL IN ACCORDANCE WITH
LOCAL CODES

ONE TEMPERA TURE - ONE HEA TER HORIZONTAL STORAGE T ANK

FORCED CIRCULA TION WITH OR WITHOUT BUILDING RECIRCULA TION

DANGER

TEMPERATURE SETTING SHOULD NOT EXCEED

SAFE TEMPERATURE AT FIXTURES. SEE WATER

TEMPERATURE CONTROL WARNING ON PAGE 4.

IF HIGHER PREHEAT TEMPERATURES ARE

NECESSARY TO OBTAIN ADEQUATE BOOSTER

OUTPUT, ADD AN ANTI-SCALD VALVE FOR HOT

WATER SUPPLIED TO FIXTURES.

*PIPE TO OPEN DRAIN

INST ALL IN ACCORDANCE
WITH LOCAL CODES

23

TWO TEMPERATURE - ONE HEATER HIGH TEMPERATURE

WITH OR WITHOUT BUILDING RECIRCULATION

TEMPERATURE SETTING SHOULD NOT EXCEED SAFE

DANGER

TEMPERATURE AT FIXTURES. SEE WATER

TEMPERATURE CONTROL WARNING ON PAGE 4. IF

HIGHER PREHEAT TEMPERATURES ARE NECESSARY

TO OBTAIN ADEQUATE BOOSTER OUTPUT, ADD AN

ANTI-SCALD VALVE FOR HOT WATER SUPPLIED TO

FIXTURES.

CAUTION: IF BUILDING COLD WATER SUPPLY HAS A

BACK-FLOW PREVENTER, CHECK VALVE OR WATER

METER WITH CHECK VALVE PROVISIONS FOR THERMAL

EXPANSION OF WATER IN THE HOT WATER SYSTEM

MUST BE PROVIDED.

*PIPE RELIEF VALVE TO OPEN DRAIN.

NOTE: IF TEMPERED WATER IS

RECIRCULATED, RETURN LINE SHOULD BE

CONNECTED AT POINT A.

INSTALL IN ACCORDANCE WITH LOCAL

CODES.

24

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 28.

CAUTION: IF BUILDING COLD WATER SUPPLY HAS A BACK-FLOW

PREVENTER, CHECK VALVE OR WATER METER WITH CHECK VALVE

PROVISIONS FOR THERMAL EXPANSION OF WATER IN THE HOT WATER

SYSTEM MUST BE PROVIDED.

DANGER

TEMPERATURE SETTING SHOULD NOT EXCEED SAFE TEMPERATURE AT

FIXTURES. SEE WATER TEMPERATURE CONTROL WARNING ON PAGE 4.

IF HIGHER PREHEAT TEMPERATURES ARE NECESSARY TO OBTAIN

ADEQUATE BOOSTER OUTPUT, ADD AN ANTI-SCALD VALVE FOR HOT

WATER SUPPLIED TO FIXTURES.

25

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

WITH OR WITHOUT BUILDING RECIRCULATION

TEMPERATURE SETTING SHOULD NOT EXCEED SAFE TEMPERATURE AT

DANGER

FIXTURES. SEE WATER TEMPERATURE CONTROL WARNING ON PAGE 4.

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 TO 150°F SHOULD BE MAXIMUM WATER TEMPERATURE

MAINTAINED IN THE PRE-HEATERS.

120°F SHOULD BE THE MINIMUM TEMPERATURE OF WATER IN THE

PRE- H EATERS.

CONNECT CIRCULATING LINE FROM FIXTURES, IF USED, TO COLD

WATER SUPPLY LINE OF PRE-HEATER.

CONNECT CIRCULATING LINE OF 180°F OR BOOSTED WATER, IF

USED, TO INLET WATER LINE TO BOOSTER.

INSTALL IN ACCORDANCE WITH LOCAL CODES.

26

TWO TEMPERATURE - ONE HEATER HIGH TEMPERATURE

WITH RECIRCULATION OF SANITIZING LOOP

DANGER

TEMPERATURE SETTING SHOULD NOT EXCEED SAFE TEMPERATURE AT

FIXTURES. SEE WATER TEMPERATURE CONTROL WARNING ON PAGE 5.

IF HIGHER PREHEAT TEMPERATURES ARE NECESSARY TO OBTAIN

ADEQUATE BOOSTER OUTPUT, ADD AN ANTI-SCALD VALVE FOR HOT

WATER SUPPLIED TO FIXTURES.

CAUTION: IF BUILDING COLD WATER SUPPLY HAS A BACK-FLOW

PREVENTER, CHECK VALVE OR WATER METER WITH CHECK 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 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.

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.

27

MANIFOLD KITS

Precision cut type L all copper A.O. Smith manifold kits assure water flow balance of all units. Without this balance, the full water

heating and storage potential of the system cannot be achieved. Plus, the units with the higher water flow may have a shortened life.

Unions shown in piping diagrams are not included in the manifold kits.

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

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

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CHECKLIST AND SERVICE INFORMATION

IMPORTANT

The installer may be able to observe and correct certain problems which

might arise when the unit is put into operation or when it is re-fired after a

prolonged shutdown. HOWEVER, it is recommended that only qualified

servicemen, using appropriate test equipment, be allowed to service the

heater.

BE SURE TO TURN OFF THE ELECTRICITY WHENEVER POSSIBLE OR

APPROPRIATE WHILE CHECKING EQUIPMENT.

WARNING

FAILURE TO FOLLOW THESE INSTRUCTIONS CAN RESULT IN SERIOUS

PERSONAL INJURY OR DEATH.

CAUTION: LABEL ALL WIRES PRIOR TO DISCONNECTION WHEN

SERVICING CONTROLS. WIRING ERRORS 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.

3. The capacity of the heater may have been exceeded by a large

demand for hot water.

 Large demands require a recovery period to restore water

temperature.

4. Colder incoming water temperature will lengthen the time required to

heat water to the desired temperature.

 If the heater was installed when incoming water temperature was

warm, colder water creates the effect of less hot water.

5. Look for hot water wastage and leaking or open hot water faucets.

 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.

 Excessive water temperature.

 Faulty relief valve.

Excessive water pressure is the most common cause of relief valve

leakage. It is often caused by a closed system. If a check valve is in the

inlet system it will not permit the expanded hot water volume to equalize

pressure with the main. The relief valve must release this water or the

water heater or plumbing system will be damage d. Refer to 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 also.

TROUBLE-SHOOTING

WARNING

JUMPING OUT COMPONENTS AND/OR CIRCUITS DURING

TROUBLESHOOTING CAN CAUSE SERIOUS PROBLEMS WITH THE UNITS

OPERATING SEQUENCE AND IGNITION SAFETY. IF YOU DO NOT HAVE

THE PROPER TEST EQUIPMENT, I.E. A VOLT-OHM METER AND A

MICROAMMETER, DO NOT ATTEMPT TO TROUBLESHOOT OR REPAIR A.O.

SMITH EQUIPMENT.

6. Sediment or lime scale may be affecting water heater operation.

Refer to MAINTENANCE for details.

7. The heaters temperature high limit sensor has activated. Press the

reset button on the thermostat.

8. Burner may not be firing at proper rate.

 Check gas pressure. Adjust to obtain required manifold pressure.

9. Burner fan wheel may be dirty.

 Clean fan wheel with a stiff brush.

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

elbow.

 Verify the condensate drains from the unit without restriction.

WATER IS TOO HOT

1. Refer to WATER TEMPERATURE CONTROL.

WATER HEATER MAKES SOUNDS

1. Sediment or lime scale accumulations cause rumbling and pounding

noises when the heater is operating.

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 located

on page 15 before continuing.

Make sure the appliance is connected to a 120V AC power supply, manual

gas valve is in the ON position, and all electrical connections are secure

before continuing to troubleshoot this appliance.

CAUTION

THE WATER HEATER IS POLARITY SENSITIVE. BEFORE APPLYING

ELECTRICITY TO THIS HEATER BE CERTAIN THAT SUPPLY HEATED WIRE

TO GROUND CHECK INDICATES ZERO VOLTAGE.

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MOTOR WILL NOT RUN

1. Confirm 120V AC to the controller. Also, to verify correct polarity, check

for 120 V AC between hot supply and ground.

If there is no voltage, check for a loose connection where it connects to

the controller.

2. If there is 120 volts to the controller, check for loose connections or a

locked rotor. If the rotor cannot be freed the motor and blower assembly

must be replaced.

MOTOR RUNS, PREPURGE TIME ELAPSES BUT MAIN

FLAME NOT ESTABLISHED.

1. Check to see if main manual gas valve is open.

2. Check for a loose connection at the transformer, or a defective

transformer.

3. Check for a loose connection at the gas valve.

4. Check for open pressure switches or open reset button. Check for

blockage in the intake and exhaust venting or at the vent hoods. If no

blockage is found, check vinyl tubing for cuts or crimps. If this tubing is

damaged it must be replaced. If these steps do not eliminate the problem,

replace the pressure switches.

5. Check to see if there is resistance across the igniter terminal with an

OHM meter. If there is no continuity, the igniter is broken and should be

replaced.

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

pressure is 14.0" W.C. maximum. The gas valve supplied on this appliance

is not designed to open against a higher pressure. At this time also

check that the inlet pressure is not lower than the minimal gas supply

pressure, as shown in Table 4: that is, for Natural Gas, 5.0" W.C. for

BTH 120 & 250 or 4.5" W.C. for BTH 150 & 199 or; for L.P. Gas, 11.0"

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" W.C. for BTH 120

& 250 or 3.5" W.C. for BTH 150 & 199 or; for L.P. Gas, 10.0" W.C. If the

manifold pressure is not correct then adjust accordingly. See

ADJUSTMENT PROCEDURE in OPERATING INSTRUCTIONS selection,

page 18, for the manifold pressure adjustment procedure.

6. If the inlet and manifold pressures are within the limits specified in step

5, then reset the appliance. Verify 24V AC at the gas valve during the

three (3) second ignition trial, after the igniter reaches operating

temperature. If 24V AC at the gas valve is not seen during this period,

the controller must be replaced.

If there is 24V AC at the gas valve during the four second ignition trial

and the manifold pressure does not increase above 0" W.C. then verify

that the manual gas control valve is in the ON position (see page 20).

If the valve is in the ON position and the previous voltage and gas

pressure conditions are met, then the gas valve is defective and must

be replaced.

the inlet pressure is not greater than 14.0" W.C. or lower than the

minimal gas supply pressure, as shown in Table 4: that is, for Natural

Gas, 5.0" W.C. for BTH 120 & 250 or 4.5" W.C. for BTH 150 & 199 or; for

L.P. Gas, 11.0" W.C. pressure. Also, the manifold pressure should rise

during the three (3) second trial for ignition to the manifold pressure

value for the individual unit listed in Table 4: that is, for Natural Gas, 4.0"

W.C. for BTH 120 & 250 or 3.5" W.C. for BTH 150 & 199 or; for L.P. Gas,

10.0" W.C. If the manifold pressure is not correct then adjust accordingly.

See ADJUSTMENT PROCEDURE in OPERATING INSTRUCTIONS section,

page 18, for the manifold pressure adjustment procedure.

3. Check for the reversed polarity in the supply wiring. This controller is

polarity sensitive. If the hot and neutral supply wires are reversed, the

controller will not sense flame. Reverse the supply wires and try to fire

the unit.

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

the unit.

4. Check connecting wire to the flame sensor. Verify that the flame sensor

has not been damaged in any way.

5. Verify that the air supply is adequate. The air inlet screen or blower

wheel may be restricted. Also, check the installation for proper ventilation.

See AIR REQUIREMENTS.

6. Check the venting system for the correct sizing, excess or insufficient.

See VENTING.

7. Check for a maximum inlet pressure of 14.0" W.C. and the manifold

pressure as listed in Table 4: that is, for Natural Gas, 4.0" W.C. for BTH

120 & 250 or 3.5" W.C. for BTH 150 & 199 or; for L.P. Gas, 10.0" W.C.

Please note that the manifold pressure listed is the maximum value for

the manifold pressure. Do not set the manifold pressure higher than the

value shown for your heater in Table 4. Overfiring the heater will result

in rough ignition and/or noisy operation.

8. Confirm that the air inlet screen (see Figures 7 & 8) is free of obstructions.

CAUTION

Do not reach into the burner housing or combustion chamber if the heater

is still hot. Allow the heater to cool and always use gloves as the combustion

chamber and the burner sleeve and housing can become very hot after

operation. Overfiring is a dangerous condition that must be corrected

immediately.

NOISY BURNER OPERATION

The exhaust of this unit produces some noise. This noise may be

objectionable if the exhaust terminal is located too close to the opening of

an occupied space. The noise may also be objectionable if the exhaust is

located in the confined space between two buildings such as an alley or

walkway. Since everyone's perception and tolerance for background noise

varies, there is no standard recommendation. The best option when the

noise is a concern is to locate the exhaust as far away from any occupied

spaces as practical.

If noise becomes more than one can tolerate, a dampening muffler is available

through our Product Service Division. See REPLACEMENT PARTS segment

below.

GAS FAILS TO SHUT OFF

Note that a positive manifold pressure reading of approximately 1.5"

W.C. is normal during the prepurge portion of the ignition cycle due to

the location of the gas orifice.

MOTOR RUNS, BURNER LIGHTS MOMENTARILY,

THEN LOCKS OUT

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

purged from the gas line.

2. If the burner lights momentarily but does not sustain ignition, verify that

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, 5621 W. 115th Street,

Alsip, IL 60482, 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.

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Model BTH Limited Warranty

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

1. THE TANK

If the glass-lined tank in this water heater shall prove upon examination by the warrantor to have leaked due to natural corrosion from potable water

therein, during the first THREE years after initial installation, the warrantor will supply a replacement tank less burner and controls or a complete new

A.O. Smith water heater of equivalent size and current model at the warrantor's option. Some government agencies are requiring energy efficient

standards for water heaters. In the event regulations prohibit sale of a model of equivalent size and construction, A.O. Smith will provide a model

which complies with the regulations of your area., in which case the consumer will be charged the difference in price between the like replacement

and the energy efficient model required. The warranty on the replacement water heater will be limited to the unexpired term of the original warranty.

2. ALL OTHER 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, certified by A.G.A. and

approved by the American Society of Mechanical Engineers, must have been installed.

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

(1) at temperatures not exceeding the maximum setting of its thermostat;

(2) at water pressure not exceeding the working pressure shown on the heater;

(3) when operated free of the damaging effects of uncontrolled water hammer;

(4) when filled with potable water, free to circulate at all times;

(5) in a non-corrosive and non-contaminated atmosphere;

(6) with factory approved anode(s) installed;

(7) in the United States, its territories or possessions, and Canada;

b. Any accident to the boiler, any misuse, abuse (including freezing) or alteration of it, any operation of it in a modified form, or any attempt to repair

tank leaks will void this warranty.

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

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

4. SERVICE AND REPAIR EXPENSES

5. LIMITATIONS ON IMPLIED WARRANTIES

6. CLAIM PROCEDURE

7. DISCLAIMERS

valve installed on the heater is not an acceptable method.

Under the limited warranty the warrantor will provide only a replacement water heater or part thereof. The owner is responsible for all other costs.

Such costs may include but are not limited to:

a. Labor charges for service removal, repair or reinstallation of the water heater or any component part;

b. Shipping, delivery, handling, and administrative charges for forwarding the new heater or replacement part from the nearest distributor and

returning the claimed defective heater or part to such distributor.

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

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

fo rthe 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.

Any claim under the warranty should be initiated with the dealer who sold the boiler, or with any other dealer handling the warrantors products.

If this is not practicable, the owner should contact:

U.S. Customers Canadian Customers

A. O. Smith Corporation A. O. Smith Enterprises Ltd.

5621 W. 115th Street P. O. Box, 310 - 768 Erie Street

Alsip, IL 60803 Stratford, Ontario N5A 6T3

Telephone: [phone] Telephone: [phone]

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.

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

THE INSTALLATION, OPERATION, REPAIR OR REPLACEMENT OF THE BOILER. THE WARRANTOR SHALL NOT BE RESPONSIBLE FOR

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

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

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

a. Some states do not allow the exclusion or limitation of the incidental or consequential damage, so the above limitations or exclusions may not

apply to you.

b. This warranty gives you specific legal rights, and you may also have other rights which vary from state to state.

Fill in the following for your own reference. Keep it. Registration is not a condition of warranty. The model and serial number are found on the heaters

rating plate.

Date Installed________________________Model No. __________ Serial No. ________________________________________________

Dealers Name _____________________________________________________________________Phone No. ________________________________________________

Dealers Address__________________________________________________City and State___________________________________________Zip Code _____________

FILL IN WARRANTY AND KEEP FOR FUTURE REFERENCE.

31

A.O. SMITH WATER PRODUCTS CO., INC.

5621 W. 115TH STREET  ALSIP, ILLINOIS 60803

PHONE: [phone]  FAX: [phone]

WWW.HOTWATER.COM  E-MAIL: [e-mail]

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