A.O. Smith 960 through, 967 through User Manual

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Page 1

A.O.Smith

Cyclone XHE

Extra-High Thermal Efficiency

ELS COVERE

BTH Models 120 through 250

Series 960 through 967, 970 and 973

Service Handbook

Part No. TC-044R6 • Printed in the U.S.A. • 1105

Water Heaters

Page 2

BTH Service Handbook

Introduction

Installation

Clearances Gas Requirements Venting

Air Requirements

Contaminated Air..........................

Flammable Items..........................

Multiple Unit Piping Condensation

Operation

Sequence of Operation

Controls........................................

Circuit Boards...............................

Troubleshooting

Pre-Service

120 VAC to Control

Transformer..................................

ECO Check

Temperature Probe

Pressure Switch Continuity . . Blower Pressure Switch Performance

120 VAC to Ignitor......................

Ignitor Resistance

Gas Valve Test...........................

Gas Pressure Check

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3 . .4 -8 .9-11

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.........18

. 19-20 .21-22

.........23

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24 .25-26 .27-28 .29-30

.........

Component Information

Orifice Tables Pressure Switches

Wiring Diagrams

Service Aids

BTH Muffler

Questions & Answers

Error Codes

Service Checklist.................................42

Parts Lists

970 & 973 Series...........................43-47

966 & 967 Series...........................48-59

960 Series 962 Series

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35-36

60-63

64-71

37 38

39 40

Page 3

BTH SERVICE HANDBOOK

INTRODUCTION

This service handbook is designed to aid in servicing and troubleshooting A. O. Smith BTH 120 - 250 water heaters. No duplication or reproduction of this book may be made without the express written authorization of the A. O. Smith Water Products Company.

The following text and illustrations will provide you with a step by step procedure to verify proper installation, operation and troubleshooting procedures. Additional quick reference data is included to assist you in servicing this product.

The information contained in this handbook is designed to answer commonly faced situations encountered in the oper ation of the BTH product line and is not meant to be all inclusive. If you are experiencing a problem not covered in this handbook, please contact the A. O. Smith Technical Information Department at 1-800-527-1953 or your local A. O. Smith Water Products Company Representative for further assistance. This handbook is intended for use by licensed plumbing professionals and reference should be made to the instruction manual accompanying the product. This hand book contains supplemental information to the BTH instruction manual.

Qualifications: Installation or service of this water heater requires ability equivalent to that of a licensed tradesman in

the field involved. Plumbing, venting, gas supply and electrical testing skills are required.

Tools Required:

• Phillips head and flat tip screw drivers

• Set of marked drill bits

• Electric multimeter tester

• Gas pressure gauge or manometer (gauge — AOS part number 8099-2)

• Water pressure gauge (A OS part number 4798)

• Digital manometer or draft gauge

• Thermometer (AOS part number 4870 — range 0 thru 220°F)

• 1/2”, 1” and 11/8” sockets

• Pipe wrench for union disconnect

NOTE Also, have a copy of the instruction manual for the model and series BTH that you are servicing. Revision 2 includes:

• an added Multiple Venting statement on page 3 and a new Blower Motor Ohms Resistance Table on page 25. The Pressure Switch Table on page 32 was expanded/revised.

Revision 3 includes:

• clarification to Step 13, 14 and 15 Test.

• BTH 120 Propane information on pages 31,32, and the Parts List.

• revised part number — page 34, Step 11.

Revision 4 dated 04/02 includes:

• expanded error code information on page 36.

"fRevision 4 dated 04/03 includes:

• revised sequence of troubleshooting. Minor corrections.

Revision 6 includes:

• 970 & 973 Series product information. Minor corrections.

f. Handbook cover should have stated revision 5.

Technical Training Department TC-044 Revision 6

A. O. Smith Water Products Co.

Page 4

BTH SERVICE HANDBOOK

INSTALLATION

CLEARANCES

This portion of the handbook will review often overlooked installation require

ments. The installation manual covers these items in detail. BTH water heaters are approved for installation on com

bustible flooring. The minimum clear ance to combustibles or non

LEFT

combustibles is 0 inches from the sides waLiI and rear, 0 inches from vent piping, and

1.5 inches from the top cover. A 24 inch top view

clearance for all serviceable parts is

recommended. Clearances may vary

between BTH models. See installation

manual or the label on the heater for your specific model.

CEILING

‘1.5

FRONT VIEW

*For removal of top cover

WALL

RIGHT WALL

REAR WALL

l_gpj

. 0" ,

.ÜT

RIGHT

WALL

GAS REQUIREMENTS

NOTE: Pressure without capacity will result in lockout. Follow the piping guidelines in the

installation manual. The supply gas pressure is normally measured at the dirt leg or at the inlet gas

pressure tap on the gas valve. This reading must be measured with ‘flowing’ gas. The manifold gas pressure is measured at the manifold pressure tap on the gas valve when the

gas is flowing. The gas valves used on all BTH water heaters are 24 VAC combination step open

ing gas valves. They incorporate the main valve and pressure regulator into one body.

REGULATED GAS SUPPLY LINE

GAS SUPPLY SPECIFICATIONS

NATURAL GAS NATURAL GAS PROPANE GAS

PRESSURE REGULATOR ADJUSTMENT (COVER screw'

INLET PRESSURE TAP

GAS INLET

BTH 120 & 250 BTH 150 & 199

GAS VALVE ON/OFF

TH & TR TERMINALS (MAIN VALVE)

VIANIFOLD

PRESSURE TAP

GAS OUTLET

BTH 120, 150 &

199

Max. Gas Supply Pressure Inches W.C.

Nominal Gas Supply Pressure Inches W.C.

Minimal Gas Supply Pressure Inches W.C.

Manifold Pressure Inches W.C.

12.0 (3 kPa) 12.0 (3 kPa) 14.0(3.45 kPa)

7.0 (1.75 kPa) 7.0 (1.75 kPa) 11.0 (2.74 kPa)

5.5 (1.37 kPa) 4.5 (1.12 kPa) 11.0 (2.74 kPa)

4.0 (1 kPa) 3.5 (0.8 kPa) 10.0 (2.5 kPa)

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TC-044 Revision 6

Page 5

BTH SERVICE HANDBOOK

NSTALLATION

VENTING

Equivalent Feet of Pipe Intake or Exhaust

VENT LENGTH TABLE

NUMBER OF 90°

ELBOWS

ONE (1)

TWO (2)

THREE (3) 7 35 105

FOUR (4) 7

FIVE (5) 7

SIX (6) 7

3” MINIMUM

PIPE (FEET)

7 45 115 7

3” MAXIMUM

PIPE (FEET)

40 110

30 100

- 95

4” MAXIMUM

PIPE (FEET)

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 vent ing. See Vent Length Table.

The 3-inch venting terminals (provided) must be used with the 4-inch venting by adding 4x3 reducing coupling 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 Vent Length Table.

DIRECT VENTING

The air intake provided on the unit contains a mesh screen (see Figure below) to prevent large par ticles from entering the unit.

3” (7.6CM) 45° PVC ELBOW WITH MESH SCREEN

MESH

SCREEN

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 follow

RESTRICTOR

ing Figure) PROVIDED ON THE UNIT.

Technical Training Department TC-044 Revision 6

A. O. Smith Water Products Co.

Page 6

IC IC IC IC IC IC IC

—p l_l l_l

SEALED DIRECT VENT VERTICAL

z[#

BTH SERVICE HANDBOOK

INSTALLATION

VENTING CONFIGURATIONS

SEALED DIRECT VENT SIDEWALL

INDOOR CONVENTIONAL

VERTICAL

IE EE EE EE EE EE EE EE EE

INDOOR CONVENTIONAL

SIDEWALL

SEALED DIRECT VENT

HORIZONTAL INTAKE

VERTICAL EXHAUST

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 (ATSM F-411), or ABS (ASTM D-2661) pipe. The fittings, other than the TERMINATIONS should be equivalent to PVC-DWV fit tings 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 Tee (PVC Material). PVC Materials should use ASTM D-2564 Grade Cement; CPVC Material should use ASTM F-493 Grade Cement and; ABS Materials should use ASTM D-2235 Grade Cement.

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.

SEALED DIRECT VENT

VERTICAL INTAKE

HORIZONTAL EXHAUST

VENTING MATERIALS

SEALED DIRECT VENT

W/ CONCENTRIC VENT

VERTICAL TERMINATION

SEALED DIRECT VENT W/ CONCENTRIC VENT

HORIZONTAL TERMINATION

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TC-044 Revision 6

Page 7

ВТН SERVICE HANDBOOK

INSTALLATION

CONCENTRIC VENT TERMINATION

The concentric vent termination kit, Part No. 194451-000 can be used on BTH 120 - 250 Cyclone XHE water heaters. It adds zero equivalent feet to the vent system. Below are some general appli cation and installation guidelines for the concentric vent kit. Refer to the accompanying literature and the water heater installation manual for complete venting installation instructions.

This concentric vent termination kit may be used with 3 or 4 in. diameter pipe systems. When con necting to a 4 in. diameter pipe system a 3 x 4 in. field supplied reducer is to be installed at the intake and exhaust connection of the concentric vent termination kit. See water heater installation and operation manual for venting specification

3" DIAMETER PVC VENT/EXHAUST

4" DIAMETER

Dimension 21 1/8 in. may be lengthened to 60 in. maximum. Dimension 21 1/8 in. may also be shortened by cutting the pipes, provided in the kit, to 12 in. minimum. Dimension 39 will change accordingly as dimension 21 1/8 in. is lengthened or shortened

MAINTAIN 12 IN.

VENT

(18 IN. FOR CANADA)

Vertical Installation

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A. O. Smith Water Products Co.

Page 8

BTH SERVICE HANDBOOK

INSTALLATION

VENTING CLEARANCES

This illustrates the exterior clearances for these BTH units when installed as direct vent heaters. NOTE: 24 inches between inlet and outlet is a MINIMUM. Greater distance is recommended.

In colder climates increasing the 24” minimum to a maximum practical distance will reduce the possibility of frost over from side winds blowing exhaust vapors into the air intake.

BTH MODEL 120

BTH MODEL 150-199

BTH MODEL 250

EXHAUST

VENT

TERMINAL

SIDE WALL

INTAKE

VENT^

TERMINAL

--J II

-JU iL_«

■ —*1

PLUMBING VENT ROOF BOOT

(TVP. BOTH PIPES) 24* MIN

PLUMBING VENT

ROOF BOOT

(TYP. BOTH PIPES) 24

—] II

1! i

EXHAUST

n II

VENT

TERMINAL

A SB; 12° ABOVE ROOF OR SNOW ACCUMULATION LEVEL

A & B ; 12* ABOVE ROOF OR SNOW ACCUMULATION LEVEL

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TC-044 Revision 6

Page 9

BTH SERVICE HANDBOOK

NSTALLATION

EXTERIOR SIDEWALL CLEARANCES

Horizontal Vent (Using Room Air for Combustion)

When multiple units are directly vented through a wall, all intake vent terminals must be no lower

than the highest exhaust vent terminal.

CAUTION

DO NOT TERMINATE THE VENTING WHERE NOISE FROM THE EX

HAUST OF INTAKE WILL BE OBJECTIONABLE. THIS INCLUDES LOCATION CLOSE TO

OR ACROSS FROM WINDOWS AND DOORS. AVOID ANCHORING THE VENT AND

INTAKE PIPES DIRECTLY TO FRAMED WALLS, FLOORS OR CEILINGS UNLESS RUB BER ISOLATION PIPE HANGERS ARE USED. THIS PREVENTS ANY VIBRATIONS FROM BEING TRANSMITTED INTO THE LIVING SPACES.

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ВТН SERVICE HANDBOOK

INSTALLATION

AIR REQUIREMENTS

MINIMUM AIR FOR COMBUSTION

10 Cubic Feet of Air Per 1000 BTUH

2.5 CU.

EXCESS

AIR

Stoichiometric or theoretical complete combustion requires 10 cubic feet of air per 1000 BTUH of gas input. The National Fuel Gas Code also recommends an additional 2.5 cu.ft. of “excess air”. This 12.5 cu.ft. minimum supply air per 1000 BTUH input applies to natural and propane gas mod els.

The National Fuel Code also specifies minimum make-up air opening sizes for various building installations (Ref: NFPA 54, ANSI Z223.1, sec 5.3).

MAKE-UP AIR

Direct Vent Installation

This model is approved for direct venting either horizontally or vertically or conventional venting horizontal or vertical. Direct venting avoids using room air for combustion and eliminates the need for additional air intake ducts.

A. O. Smith Water Products Co.

Technical Training Department

TC-044 Revision 6

Page 11

BTH SERVICE HANDBOOK

INSTALLATION

MAKE-UP AIR

Direct Communication

12”

Each opening shall have a free area not less than:

1 square inch per 4000 BTUH total input all appliances within the enclosure

Inlake Air

Iniciko Air Opening

Opening

12”

A fresh supply of make-up air for combustion can be supplied to the heater through make-up air

openings, which directly communicate with the out of doors. Two openings are required — one

within 12 inches of the top of the enclosure and one within 12 inches of the bottom of the enclosure.

Each opening shall have a free area of not less than 1 square inch per 4000 BTUH of the total input

of all appliances within the enclosure. The lower opening is primarily providing combustion air. The upper opening is providing vent dilu

tion air and acts as a relief opening for flue gases should the vent become obstructed or a down

draft condition occur.

MAKE-UP AIR Vertical Ducts

Air Intake Ducts

12”

Each opening shall have a free area not less than:

1 square inch per 4000 BTUH total input all appliances within the enclosure

12”

Often it is more practical to install vertical make-up air ducts to the outdoors. Again, two openings are required — within 12 inches (30 cm) of the top of the enclosure and one within 12 inches (30 cm) of the bottom of the enclosure. Each opening shall have a free area of not less than 1 square inch per 4000 BTUH of the total input of all appliances within the enclosure.

Technical Training Department TC-044 Revision 6

A. O. Smith Water Products Co.

Page 12

BTH SERVICE HANDBOOK

NSTALLATION

MAKE-UP AIR

Horizontal Ducts

E.K ÌÌ opiMiin<| sImII

hriVH <-1 liee nnl

less

IImm:

1 s(|ii<iie im li pel vomì BTUH Ifil.il inpiil , «ill «ippliano os within llie ent Insule

Air Intake Ducts

12”

12’

When the heater is installed in an interior room with no roof access for vertical ducts, horizontal make-up ducts should be installed. When using horizontal ducts, two openings are required - within

12 inches (30 cm) of the top of the enclosure and one within 12 inches (30 cm) of the bottom of the enclosure. Each opening shall have a free area of not less than 1 square inch per 2000 BTUH of the total input of all appliances within the enclosure.

INSUFFICIENT MAKE-UP AIR

Backdraft

Insufficient make-up air is a major cause of combustion problems. One common example is in a restaurant installation where exhaust vent equipment was not considered in sizing make-up air requirements. This may result in air being backdrafted by the restaurant exhaust equipment through the heater causing flue gas spillage, flame roll out, improper combustion, inconsistent pilot operation, and/or erratic heater shutdown.

A possible solution to this situation would be to use a BTH with direct venting. A less common service issue associated with a backdraft or negative pressure room would be the

opening or closing of air pressure switches. This may result in erratic or no heater operation.

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TC-044 Revision 6

Page 13

BTH SERVICE HANDBOOK

INSTALLATION

CONTAMINATED AIR

^ RUST

CHIPS

Along with adequate make-up air, the quality of the air is important. Contaminants in combustion air can lead to premature heater failure. Vapors from bleaches, soaps, salts, etc. are drawn into the combustion chamber with the make-up air and, once fired, mix with water vapor in the gasses to form extremely corrosive hydrochloric or hydrofluoric acid and other corrosive by-products. Dust drawn in may build up on the blower or clog the main burner ports. Also, be certain to examine the exterior area around the air intake of a direct vent installation for the contaminants.

FLAMMABLE ITEMS

Flammable items or pressurized containers or any other potentially 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 or in the area of the exterior air intake of a direct vent

installation. Direct venting does not eliminate the need to remove flammable or corrosives from the

area surrounding the heater.

Technical Training Department

TC-044 Revision 6 12

A. O. Smith Water Products Co.

Page 14

BTH SERVICE HANDBOOK

INSTALLATION

MULTIPLE UNIT — WATER PIPING

A. O. Smith Water Products Co.

Technical Training Department

TC-044 Revision 6

Page 15

ВТН SERVICE HANDBOOK

INSTALLATION

CONDENSATION

The average dewpoint of natural gas flue products is 127° F. Propane flue products is 119° F. With

70° F ambient air temperature and 180° F stored water temperature, exhaust gas will be approxi mately 140° F. Recommended starting point for water storage is 120° F.

The extra high thermal efficiency of the BTH will result in condensation in the flue passage. The fol

lowing answers common questions about this condensation. CAN I DRAIN THIS CONDENSATION TO A FLOOR DRAIN? The “Corrosion Resistance of Cast

Iron Soil Pipe” by the Ductile Metals Association (formally the Cast Iron Soil Pipe Institute) states

that: “Internal corrosion of cast iron soil pipe and fittings can be caused by strong acids or other reagents

having an acidity of pFI 4.3 or less if allowed to contact cast iron pipe for an extended period of time without sufficient dilution to raise the pH valve about 4.3. By avoiding low pH discharges, internal corrosion problems can be limited or eliminated, assuring the owner many years of service.”

WHAT ABOUT THE pH VALUES OF CONDENSATE AND SODA POP? The pH of the BTH con densate average 4.5 which is approximately 4 times less concentrated than the limit of 4.3 recom

mended by the DMA. Any water flow in the drain rapidly dilutes the condensate even more. A can of leading carbonated cola drink measured a pH of 2.5 which is 300 times more concentrated than the BTH condensate.

WHAT DOES THE pH SCALE MEAN? The pH value is a measure of acidity of alkalinity. A pH of

7 is neutral. Numbers from 7 to 1 indicate increasing acidity and numbers from 7 to 14 indicate

increasing alkalinity. The pH scale is similar to the Richter scale used to measure earthquakes.

Each number indicates a change of 10 times the concentration of the previous value. A pH 6 is 10 times more concentrated than a pH 7, a pH 5 is (10x10) 100 times pH 7 and pH 4 is (10x10x10)

1,000 times pH 7, etc. WHAT ABOUT CONDENSATE NEUTRALIZERS? Condensate neutralizers are usually not nec

essary. A condensate neutralizer is easy to make by filling a short length of 2” or 3” PVC pipe with

landscape marble chips, capping it and installing it in series with the condensate drain of the equip

ment. Most commercial neutralizers are off the market because of poor demand for the product. Condensation from the exhaust vent piping and tank internal flue way must be allowed to drain. A “blocked flue” indication will often be your first indication that condensate is not draining.

Technical Training Department

TC-044 Revision 6 14

A. O. Smith Water Products Co.

Page 16

BTH SERVICE HANDBOOK

OPERATION

SEQUENCE OF OPERATION

A. O. Smith Water Products Co.

Technical Training Department

TC-044 Revision 6

Page 17

BTH SERVICE HANDBOOK

OPERATION

CONTROLS

NORMAL INDICATIONS / READINGS / SETTINGS

During Call for Heat

On/Off switch in the “on” position

DISPLAY PANEL (CONTROL PANEL)

Water Temperature F° — current average tank water temperature displayed

120 VAC LED light on 24 VAC LED light on High LimitA/ent Switch LED light on Blower (while blower is running) LED light

on Air Pressure Switch (while blower is

running) LED light on Control Status LED light on Gas Valve (during ignition period and

heating cycle) LED light on

The water temperature inside the tank must be below the current temperature setting to activate a call for heat. Pressing the Set/Reset button approximately 4-6 seconds after powering up the water heater will reveal the current temperature setting. See the instructions below for how to view or change temperature settings.

Power On Display Sequence / Indication

120

--------

M Press Set/Reset button at this moment |

¡to initiate a control operational check i

1 Factory default setting - 12. ¡

¡Tank Temperature

Press Set/Reset button to view or

ladjust current temperature setting.

Power on display. j

¡Supply voltage i

j ¡Temperature Offset. i

To View Or Change Temperature Settings

Press the Set/Reset button once to view the current temperature setting.

' 1

Press and hold the Set/Reset button down to change the current setting.

When pressed and held down it will raise/lower the setting, quickly releasing and pressing down/holding again will switch between raising and lowering. When the desired setting is reached release the button.

The control must satisfy a call for heat with the new setting for the new setting to remain in memory. If the water heater does not satisfy a cali for heat with the new setting, the new setting is lost and the previous setting remains in effect.

Technicai Training Department TC-044 Revision 6

A. O. Smith Water Products Co.

Page 18

BTH SERVICE HANDBOOK

OPERATION

CIRCUI BOARDS

DISPLAY CIRCUIT BOARD

IGNITION CIRCUIT BOARD

'1... 2.1.4

■ -1 - •

■ ■ *

20 Conductor

. Ribbon Cable

to Display Board • • ‘ ^ ^ 'j. J 4—

is»

.....................................

■ -tj tCN2 , 12 3

, (tHaií>í*3í--í

....

, J .^Transformer

CN1

CN6 j:r>

1 2

' i '*

1 2 3 ;

3 2 1

6 5 4

4»-

1 1 2 •

.Temperature/

Eco Probe (Upper)

Temperature

Probe #2 (Lower)

Igniter

Blower

To Junction Box

1,3 Gas Valve

2 Flame Sensor

4,6 Pressure Switches

5 Ground

Technical Training Department

TC-044 Revision 6

Page 19

BTH SERVICE HANDBOOK

TROUBLESHOOTING

PRE-SERVICE TIPS

CHECK THAT:

• Insure 120 VAC power supply has correct polarity — check neutral (white) wire to ground with volt meter. It should read “0” volts.

• Tank is full of water

• Exhaust and intake vent do not exceed allowable limits

• All plugs into boards are secure

• Condensate hose is drained and open

• Proper (natural or propane) gas is supplied

120 VAC TO CONTROL

STEP 1 120 VAC TO CONTROL BOARD

j1 2 3 4 N«!

M. -a«*-

1 2

:1|CN4 ■ . ■ ^

it;* ViiRitcB*

iCN2 . 12 3

STEP 1: CHECK FOR 120 VAC TO CONTROL BOARD CN1 TERMINAL.

Condition:

• Disconnect plug from CN1 terminal.

• On/Off switch is on.

12 3 4

■ ■

CN1

• G 5 4 •

. 0 , ■

j i.mi TR'ig

To Juiiction Box

■ Black " White " Green

Check for 120 VAC black wire terminal white wire on plug.

IF... THEN

120 VAC is not present

120 VAC is present reconnect CN1 plug, continue to Step 2.

Technical Training Department TC-044 Revision 6

check On/Off switch, turn switch on, replace On/Off switch if defective, restore power to the water heater.

A. O. Smith Water Products Co.

Page 20

BTH SERVICE HANDBOOK

TROUBLESHOOTING

TRANSFORMER

STEP 2

120 VAC TO TRANSFORMER

I 120V

m-%

^ o

i'iC —

^ lonThois

STEP 2: CHECK FOR 120 VAC TO TRANSFORMER FROM PIN 1 AND 2 ON CONTROL BOARD CN4 TERMINAL.

Condition:

• Disconnect CN4 plug from control board.

• On/Off switch is on.

Check for 120 VAC between pin 1 and 2 at CN4 on the control board as illustrated above. Perform this test with the CN4 plug disconnected and the On/Off switch turned on.

IF... THEN

120 VAC is not present

120 VAC is present reconnect CN4 plug to control board, continue to Step 3.

check CN1 plug connection

replace control board if Step 1 has been performed and results were successful.

A. O. Smith Water Products Co.

Technical Training Department

TC-044 Revision 6

Page 21

BTH SERVICE HANDBOOK

TROUBLESHOOTING

TRANSFORMER (CONTINUED)

STEPS

24 VAC FROM TRANSFORMER

‘m ■'■

STEP 3: CHECK FOR 24 VAC AT TRANSFORMER CN4 PLUG ON CONTROL BOARD.

Condition:

• CN4 is plugged into control board.

• On/Off switch is on.

Insert meter probes into back of CN4 plug on pins 3 and 4 (blue and yellow wires) with CN4 plugged in and power on.

IF... THEN

24 VAC is not present 24 VAC is present

replace transformer if Steps 1 and 2 were performed and results were successful. continue to Step 4.

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A. O. Smith Water Products Co.

Page 22

BTH SERVICE HANDBOOK

STEP 4 24 VAC TO ECO

TROUBLESHOOTING

ECO CHECK

24 V

Black Black

Redj I j |Red

Ground

_ t.

1 2 3

I ^'12 •

7^CN8 ◄

1 2

■CN5 -

I 1 I 'i A

STEP 4: CHECK FOR 24 VAC BETWEEN PIN 4 ON CONTROL BOARD TERMINAL CN3 AND GROUND.

Condition:

• Disconnect CN3 plug from control board.

• On/Off switch is on.

Check for 24 VAC between pin 4 of the CN3 terminal on the control board and ground.

IF... THEN

24 VAC is not present

replace the control board if Steps 1, 2, and 3 have been performed and the results were successful.

^Temperature/

Eco Probe (Upper)

^Temperature

-----

Probe #2 (Lower)

-Igniter

24 VAC is present continue to Step 5.

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TC-044 Revision 6

Page 23

BTH SERVICE HANDBOOK

TROUBLESHOOTING

ECO CHECK (CONTINUED)

STEPS 24 VAC FROM ECO

24 V

1 2

.Temperature/

Eco Probe (Upper)

Temperature

», Probe #2 (Lower)

2 I-

Igniter

IcN4 .^ ^ ^

' Í ^

. [ *

TCN2 1 2 3

■ 1 O *5

CN1 HtnwISKflp^—To Junction Box

I I

6 5 4

Transformer

— Blower

1, 3 Gas Valve 2 Flame Sensor

• 4, 6 Pressure Switches

5 Ground

STEP 5: CHECK FOR 24 VAC BETWEEN PIN 1 ON CN3 PLUG AND GROUND.

Condition:

• Reconnect CN3 plug to control board.

• On/Off switch is on.

Insert one meter probe into the back of CN3 plug pin 1, check for 24 VAC between here and ground with CN3 plugged in and power on. (See illustration above for pin number locations.)

IF... THEN

make sure water temperature in tank is below 160° F, press Set/Reset button on

24 VAC is not present

24 VAC is present continue to Step 6.

Technical Training Department

TC-044 Revision 6 22

display panel, replace upper temperature/ECO probe if tank water temperature is

below 160 and Step 4 has been performed and results were successful.

A. O. Smith Water Products Co.

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BTH SERVICE HANDBOOK

TROUBLESHOOTING

TEMPERATURE PROBE

STEP 6 TEMPERATURE PROBE RESISTANCE

LOWER

ohms

TEMPERATURE PROBE PLUG

STEP 6: CHECK RESISTANCE OF THERMISTOR IN UPPER AND LOWER TEMPERATURE PROBES.

Condition:

• Disconnect CN3 and CN8 plugs from control board.

• On/Off switch is off.

• Multimeter is set to lowest ohms scale above expected resistance.

Check resistance between black wire connects on CN3 and CN8 plugs as shown in illustration above.

IF... THEN

ohm reading does not approximately correspond to table at given

temperatures

ohm reading does approximately correspond to table at given

temperatures

WATER TEMP

OHMS RESISTANCE

3 40 26,435 21 70 11,974

37.5 100 5,862 49 120 3,780

54.5 130 3,066 60 140 2,503

71 160 1,698 82 180 1,177

°F

NOTE: The upper and lower temperature probes contain

thermistors which are heat sensitive resistors. The control board interprets changes in thermistor resistance as changes in water temperature.

These thermistors are very reliable and should only be replaced when:

The resistance test indicates an “open” (infinite resistance) or a “direct short” (no resistance) circuit.

The nature of the service problem is temperature control and the resistance readings are significantly off when com pared to the values in the table here at the given tempera ture.

replace temperature probe if thermistor is open, shorted, or resistance value is off significantly.

continue to Step 7.

A. O. Smith Water Products Co.

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Page 25

BTH SERVICE HANDBOOK

TROUBLESHOOTING

PRESSURE SWITCH CONTINUITY

STEP 7 PRESSURE SWITCH CONTINUITY TEST

Notes: Low Gas Pressure Switch

(BTH 120 & 250 only)

is instailed on the iniet

side of the Gas Valve.

N.O. = Normally Open N.C. = Normally Closed

Blocked Inlet Switch

N. C. Contacts

Blower Prover Switch

N. O. Contacts

Blocked Outlet Switch

N. C. Contacts

Gas Valve - Top View

STEP 7: CHECK FOR CONTINUITY BETWEEN PRESSURE SWITCH TERMINALS WITH

WIRES REMOVED.

Condition:

• On/Off switch is off.

• All wires are disconnected from all pressure switches.

• Multimeter is set to lowest ohms scale.

IF... THEN

blocked inlet switch does not show continuity replace switch. blocked inlet switch does show continuity blower proving switch does show continuity replace switch. blower proving switch does not show continuity continue.

low gas pressure switch does not show continuity

low gas pressure switch does show continuity continue. blocked outlet pressure switch does not show continuity replace switch.

blocked outlet pressure switch does show continuity

continue.

check for minimum supply gas pressure of

5.0” W.C. natural gas

9.0” W.C. LP gas

replace switch if gas pressures are above these minimums.

reconnect all wires to pressure switches; continue to Step 8A.

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BTH SERVICE HANDBOOK

TROUBLESHOOTING

STEP 8A 120 VAC TO BLOWER

BLOWER

120V

|iipii|M

« 3 V

Blower

.-321

CN6 I

STEP 8A: CHECK FOR 120 VAC TO BLOWER FROM CN2 PLUG PIN 1 AND 2.

Condition:

• Reconnect all plugs to control board.

• On/Off switch is on.

• Call for heat is activated.

Insert meter probes into back of CN2 plug on pins 1 and 2 with CN2 plugged in, power on, and a

call for heat activated.

IF... AND THEN

120 VAC is not

present

replace the control board if call for heat is active and Step 7 has been performed and results were successful.

120 VAC is present

A. O. Smith Water Products Co.

blower is not running

blower is running

BTH 250, 962 & 966 Series only continue to Step 8B all other models — check CN2 plug connection, replace blower.

BTH 250, 962 & 966 Series only continue to Step 8C all other models — continue to Step 9A.

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ВТН SERVICE HANDBOOK

TROUBLESHOOTING

BLOWER (CONTINUED)

BTH 250, 962 & 966 SERIES ONLY

(Models equipped with blower speed reduction board)

STEP 8B 120 VAC TO BLOWER FROM SPEED REDUCTION BOARD

BTH 250, 962 & 966 Series oniy Blower Speed Reduction Board

Go to control board CN 5

Go to control board CN 6

Go to control

board CN 2

STEP 8B: CHECK FOR 120 VAC TO BLOWER FROM CN2 PLUG PIN 1 AND 2 ON BLOWER

SPEED REDUCTION BOARD. Condition:

• Reconnect all plugs to control board.

• On/Off switch is on.

• Call for heat is activated.

Insert meter probes into back of CN2 plug on pins 1 and 2 with CN2 plugged into blower speed reduction board. Power should be on with a call for heat activated.

IF... AND THEN

120 VAC is not present check CN2 plug connection, replace blower speed

reduction board if Step 8A has been performed and results were successful.

120 VAC is present 120 VAC is present

blower is not running check CN2 plug connection, replace the blower. blower is running

continue to Step 8C.

STEP 8C: LISTEN FOR BLOWER TO REDUCE SPEED DURING IGNITOR WARM UP PERIOD.

IF... THEN

blower runs, but does not reduce speed or stops during ignitor warm up period

blower does reduce speed during ignitor warm up period continue to Step 9A.

Technical Training Department TC-044 Revision 6

replace blower speed reduction board.

A. O. Smith Water Products Co.

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BTH SERVICE HANDBOOK

TROUBLESHOOTING

PRESSURE SWITCH PERFORMANCE

STEP 9A TAKE AIR AND GAS PRESSURE READINGS.

Blower prover and blocked outlet pressure

Blower inlet pressure

STEP 9A: CHECK PRESSURE AT SENSING PORTS ON BURNER, BLOWER INLET AND GAS VALVE.

Condition:

• All wires are reconnected to all pressure switches.

• On/Off switch is on.

• Call for heat is activated.

• Blower is running during trial for ignition.

Remove the air pressure sensing tubes from the sensing ports on the blower inlet and the burner. Using a digital manometer take a pressure reading with the blower running during a call for heat at both of these sensing ports. Take a supply gas pressure reading on the inlet side of the gas valve

as outlined in Step 13.

Record all 3 pressure readings and have them on hand. Continue to Step 9B.

AMBIENT ROOM AIR PRESSURE

NOTE: One side of the internal diaphragms on these pressure switches are vented to the room atmosphere. Due to this construction a negative or positive room air pressure can cause

erratic switch operation and the water heater to shut down. If you suspect a pressure imbalance

between the equipment room and the outdoor atmosphere, “zero” or calibrate your digital manometer to the equipment room ambient air pressure. With the manometer still on and

calibrated to the equipment room air pressure take the manometer outdoors. If the pressure

reading changes significantly you may have a pressure imbalance between the equipment room

and the outdoor atmosphere. This pressure imbalance may need to be corrected before the water

heater will operate properly.

Insure the combustion/make-up air openings into the equipment room are properly sized. Check for leaks in ductwork on any nearby air handling equipment. If there is a kitchen vent hood installed in the building, insure it is properly balanced. Missing or worn fan belts on make up air fans to vent

hoods can cause negative air pressure throughout the building.

Direct vent installations DO NOT eliminate this potential problem.

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Page 29

BTH SERVICE HANDBOOK

TROUBLESHOOTING

PRESSURE SWITCH PERFORMANCE (CONTINUED)

STEP 9B PRESSURE SWITCH CONTINUITY TEST — OPERATIONAL

Air pressure switches

Low gas pressure switch

STEP 9B: CHECK FOR CONTINUITY BETWEEN PRESSURE SWITCH TERMINALS WITH

WIRES REMOVED AND BLOWER RUNNING.

Condition:

• All wires are disconnected from all pressure switches — ends are taped off.

• On/Off switch is on.

• Call for heat is activated.

• Blower is running during trial for ignition.

• Multimeter is set to lowest ohms scale.

The wires disconnected are energized with 24 VAC from the control board. Do not allow these wires to touch ground — use electrical tape to insulate wire connects during this test.

Check for continuity with an ohm meter between terminals on all pressure switches with the wires removed and the blower running during a trial for ignition. Restart the water heater as needed.

The pressure switches are wired together in a “series” circuit. For the water heater to continue to fire and satisfy a call for heat the control board must sense a closed pressure switch circuit.

IF... THEN

continuity is not present between terminals on one or more pressure switches — the switch contacts are open.

compare the pressure reading recorded in Step 9A to the value given for that switch in the table on page 36.

compare to value for correct Model and Series number in table.

continuity is present.

Technical Training Department TC-044 Revision 6

if the pressure recorded in Step 9A is within the value shown in the table for the switch contacts to remain closed — replace the pressure switch.

if the pressure recorded in Step 9A is not within the value shown in the table for the switch contacts to remain closed — check for/ clear any restrictions in the vent and/or air intake piping, check for an excessive number of elbows or equivalent feet of pipe used in the vent and/or air intake piping.

check for/restore minimum supply gas pressure — Step13. continue to Step 10A.

A. O. Smith Water Products Co.

Page 30

BTH SERVICE HANDBOOK

TROUBLESHOOTING

120 VAC TO IGNITOR

STEP 10A

120 VAC TO IGNITOR

IGNITOR

■ 6 5 4 •

STEP 10A: CHECK FOR 120 VAC TO IGNITOR FROM PIN 1 AND 2 ON CONTROL BOARD

TERMINAL CN5. Condition:

• Disconnect CN5 plug from control board.

• On/Off switch is on.

• Call for heat is activated.

• Perform test during ignitor warm up period.

IF... THEN

120 VAC is not present

120 VAC is present on — BTH 250, 962 & 966 Series 120 VAC is present on — all other models continue to Step 11.

replace the control board if Steps 7 through 9B have been performed and results were successful.

continue to Step 10B.

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Page 31

BTH SERVICE HANDBOOK

TROUBLESHOOTING

120 VAC TO IGNITOR (CONTINUED)

BTH 250, 962 & 966 SERIES ONLY

(Models equipped with blower speed reduction board)

STEP 10B

120 VAC TO IGNITOR FROM SPEED REDUCTION BOARD

BTH 250, 962 & 966 Series only

Blower Speed Reduction Board

STEP 10B: CHECK FOR 120 VAC TO IGNITOR FROM PIN 1 AND 2 ON BLOWER SPEED

REDUCTION BOARD CN5 TERMINAL.

Condition:

• Reconnect CN5 plug on control board.

• Disconnect CN5 plug from blower speed reduction board.

• On/Off switch is on.

• Call for heat is activated.

• Perform test during ignitor warm up period — blower should be running at reduced speed.

IF... THEN

120 VAC is not present

120 VAC is present

Technical Training Department

TC-044 Revision 6

replace the blower speed reduction board if Step 10A has been performed and results were successful.

continue to Step 11.

A. O. Smith Water Products Co.

Page 32

BTH SERVICE HANDBOOK

TROUBLESHOOTING

IGNITOR RESISTANCE

STEP 11 IGNITOR RESISTANCE CHECK

■ f

CN6 CN1 CN2

STEP 11: CHECK RESISTANCE BETWEEN TWO WIRE CONNECTS AT CN5 IGNITOR PLUG

END.

Condition:

• On/Off switch is off.

• Disconnect CN5 ignitor plug from circuit board.

• Multimeter is set to lowest ohms scale above 300 ohms.

IF... THEN

ohms reading taken is not between 50 - 300 ohms ohms reading taken is between 50 - 300 ohms

replace the ignitor. reconnect CN5 plug, continue to Step 12.

A. O. Smith Water Products Co.

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Page 33

BTH SERVICE HANDBOOK

TROUBLESHOOTING

GAS VALVE TEST

STEP 12

24 VAC TO GAS VALVE

STEP 12: CHECK FOR 24 VAC TO GAS VALVE DURING TRIAL FOR IGNITION. Condition:

• All wires are reconnected.

• On/Off switch is on.

• Call for heat is activated.

• Perform test at end of ignitor warm up period.

Touch meter probes to wiring terminals on gas valve with wires from control board still connected during the ignitor warm up period.

IF... AND THEN

24 VAC is not present to gas valve

24 VAC is present gas does not flow to burner check for/restore supply gas;

24 VAC is present

gas does flow to burner continue to Step 13.

replace control board if Step 9A and 9B have been performed and results were successful.

check for/clear any restriction in the gas train;

replace the gas valve if the valve will not open

with 24 VAC applied.

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BTH SERVICE HANDBOOK

TROUBLESHOOTING

GAS PRESSURE CHECK

Attach manometer or gas pressure gauge to pressure tap on gas valve or use adapter to check

pressure ahead of valve as near as possible to valve. All appliances being served by this gas sup ply line should be operating.

IF... THEN

supply gas pressure is not between 5.0 and 14” W.C. natural gas or 11.0 and 14” W.C. propane

proper supply gas pressure is present continue to Step 14.

adjust supply gas pressure (Recommended supply minimum is 7.0” W.C. for natural gas models)

STEP 14 MANIFOLD GAS PRESSURE TEST

STEP 14: CHECK AND ADJUST MANIFOLD GAS PRESSURE.

IF... THEN

manifold gas pressure is not: natural gas models

3.5” W.C. ± 0.3” - BTH 155 & 199

4.0” W.C. ± 0.3” - BTH 120 & 250 propane gas models

10.0” W.C. ± 0.3” - all propane gas models.

manifold gas pressure is within tolerances given above ignition should occur.

adjust manifold gas pressure to values given for model and fuel type (within 0.3” W.C. tolerance)

if manifold gas pressure cannot be adjusted to maintain values given (within 0.3” W.C. tolerance) replace gas valve.

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Page 35

BTH SERVICE HANDBOOK

COMPONENT INFORMATION

FLAME SENSING ROD

AOS PART NUMBER FLAME SENSING CURRENT COMMENTS

192478

HOT SURFACE IGNITOR (HSI)

AOS PART NUMBER VOLTAGE AMP OHMS COLD COMMENTS

192638 120 VAC 1.0 50 - 300 BTH 120-250

0.7 Micro Amp (p)

BTH 120-250

ORIFICE TABLE

BTH MODEL

120 192477-3 150 192477-1 0.235 192450-1 0.875 199 192477-0 0.304 192450-0 1.031

250 120 Prop 192477-6 0.125” 192450-5** 0.872 150 Prop 192477-5 0.141” 192450-5** 0.872

MAIN BURNER

ORIFICE NO.

192477-2

MAIN ORIFICE SIZE

INCHES

0.204

0.360

AIR ORIFICES

PT. NO.

192450-3 0.788

192450-2

AIR ORIFICE

SIZE — INCHES

1.196

199 Prop

192477-4

0.166”

192450-4**

*-4 and -5 Red plated for Propane. ** -4 and -5 stamped with “P” for Propane NOTE: Hex head of main burner orifice is upstream end — gas flows out of tapered end.

1.150

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Page 36

Notes: Low Gas Pressure Switch (BTH 120 a 250 only) is installed on the inlet side of the Gas Valve.

N.O. = Normally Open N.C. = Normally Closed

Blocked Inlet Switch

N. C. Contacts

BTH SERVICE HANDBOOK

COMPONENT NFORMATION

PRESSURE SWTCHES

PRESSURE SWITCH LAYOUT PRESSURE SWITCH WIRING

LOW GAS

Blower

PRESSURE

BTH 120 & 250

(normally open)

.BLOCKED

I OUTLET(FLUE)

(normally closed)

BLOWER PROVER

(normally open)

.BLOCKED

I INLET

(normally closed)

Blower Prover Switch

N. 0. Contacts

Blocked Outlet Switch

N. C. Contacts

AA AA

CN6 Plug

Control Board

GAS VALVE

ILow Gas Pressure Switch

A. O. Smith Water Products Co.

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Page 37

BTH SERVICE HANDBOOK

COMPONENT INFORMATION

PRESSURE SWITCHES (CONTINUED)

PRESSURE SWITCHES

PART NUMBER / ACTIVATION PRESSURE^

Model Series Blocked Inlet

Normally Closed

Opens on a fall

Blower Prover

Normally Open

Closes on a rise

Low Gas Pressure

Normaily Open

Cioses on a rise

Biocked Outiet

Normaliy Ciosed

Opens on a rise

BTH 120 966 193293-000/-1.00” 193295-000/+0.45” 191149-001 /+5.00” 193294-000/+2.00”

967

193356-000/-2.00” 193295-000/+0.45” 191149-004/+9.00” 193357-000/+4.00”

970 193293-000/-1.00” 194706-000/+1.00” 191149-005/+5.20” 193294-000/+2.00” 971 193356-000/-2.00” 194706-000/+1.00” 191149-004/+9.00” 193357-000/+4.00” 973 193356-000/-2.00” 194706-000/+1.00” 191149-004/+9.00” 193357-000/+4.00”

BTH 150 960 N/A 192811-000/+4.20” N/A 192810-000/+4.35”

962 192882-000/-0.75” 193221-000/+0.45” N/A 192878-000/+2.53” 966 193363-000/-0.76” 193295-000/+0.45”

N/A

193362-000/+2.60”

967 193355-000/-1.80” 193295-000/+0.45” N/A 193357-000/+4.00” 970 193363-000/-0.76” 194706-000/+1.00” N/A 193362-000/+2.60” 971

193355-000/-1.80” 194706-000/+1.00”

N/A

193357-000/+4.00”

973 193355-000/-1.80” 194706-000/+1.00” N/A 193357-000/+4.00”

BTH 199 960 N/A 192811-000/+4.20” N/A 192810-000/+4.35”

962

192882-000/-0.75” 193221-000/+0.45”

N/A

192878-000/+2.53”

966 193363-000/-0.76” 193295-000/+0.45” N/A 193364-000/+2.87” 967 193356-000/-2.00” 193295-000/+0.45” N/A 193357-000/+4.00” 970 193363-000/-0.76” 194706-000/+1.00”

N/A 193364-000/+2.87”

971 193356-000/-2.00” 194706-000/+1.00” N/A 193357-000/+4.00” 973 193356-000/-2.00” 194706-000/+1.00” N/A 193357-000/+4.00”

BTH 250 962 192947-000/-0.77”

193221-000/+0.45” 193222-000/+4.75” 192946-000/+4.16”

966 193361-000/-0.77” 193295-000/+0.45” 191149-001 /+5.00” 193357-000/+4.00” 970 193361-000/-0.77” 194706-000/+1.00” 191149-005/+5.20” 193357-000/+4.00”

t- Pressure values are given in inches of water column pressure (“W.C.).

Negative pressure values in this table are preceded by a minus sign and indicate pressure below atmospheric: in a vacuum. Positive pressures are preceded by a “+” plus sign and indicate pressure above atmospheric.

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BTH SERVICE HANDBOOK

WIRING DIAGRAMS

BTH 120 -199/ ALL SERIES

BTH 250 / 970 SERIES

(without blower speed reduction)

DETAIL BTH 250

962 & 966 SERIES ONLY

(with blower speed reduction)

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Page 39

BTH SERVICE HANDBOOK

SERVICE AIDS

1. This type product is polarity sensitive. Be certain that your eiectricai suppiy wire neutrai has no voitage.

2. This unit wiii produce condensation — quite heaviiy at times. The outiet drain hose must be allowed to drain. Exhaust Vent piping must aiso drain condensate. Code 11 error wouid impiy that these must be checked.

3. if the unit is iocated in a coid ciimate, take steps to ensure that exhaust vapors are not puiied into the air intake. Terminate both pipes on direct vent instaiiations in the same area, but max

imize the distance between them.

4. Do not combine vent these units.

5. Pushing the reset button at random times may aiter setting of the controi. Note the sequence of operation comments on when to push this button.

6. if you make a setting change, cycle the heater with this new setting to iock it into memory.

7. The first items to check on a service caii a. Correct venting instaiiation b. Drainage of condensate from hose and exhaust vent pipe

8. BTH modeis are certified to 6.800 ft. above sea ievei with the standard orifice — air and gas.

9. The temperature dispiay board indicates average tank water temperature, if one tank sensor is “open”, the indicator wiii dispiay the active sensor temperature. (Because the top tank sensor aiso contains the high iimit-24V-sensor, disconnecting this from the controi board resuits in an error code (04).)

10. Temperature and pressure reiief vaive operation. Weeping usuaiiy indicates thermai expan sion. Large volume discharge usuaiiy indicates excessiveiy hot water operation.

11. BTH modeis are weii within decimai ievei iimits, but if you desire to iowerthe instaiiation ievei approximateiy 6 decibeis a muffier (AOS No. 195334) may be instaiied in the exhaust vent.

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Page 40

BTH SERVICE HANDBOOK

SERVICE AIDS

BTH MUFFLER

, 4” X 3” PVC

REDUCING

COUPLING

4” PVC (BOTH ENDS) \fii

SUPPORT (FIELD SUPPLIED)

4” X 4” PVC COUPLING

8 5/8”

3” PVC

VENTING

4” X 3” PVC REDUCING COUPLING (FIELD SUPPLIED)

HEATER CONDENSATE

ELBOW

57 1/4"

4” X 4” PVC . COUPLING

(FIELD SUPPLIED)

iUPPLIED)

_j^

NOTES:

1. Install muffler in vertical position only.

2. Muffler must be a minimum of 8” from top of condensate elbow.

3. The muffler inlet and outlet are 4” PVC. If venting with a 4” PVC, a 4” x 4” PVC coupling (field

supplied) must be cemented to each end of the muffler. If venting with 3” PVC, a 4” x 3” PVC

reducing coupling (field supplied) must be cemented to each end of muffler (see illustration

above.)

4” PVC

VENTING

I__I

4. Cement muffler into a location using ASTM D-2564 grade cement.

5. Secure muffler to suitable structure.

6. Operate heater through 1 heat cycle to ensure there are no exhaust leaks and there is no

obstruction of exhaust flow.

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Page 41

BTH SERVICE HANDBOOK

QUESTIONS AND ANSWERS

Q. How much electrical power is required for a BTH water heater?

A. The BTH models draw approximately 5.0 Amps Max.

Q. When should BTH’s be delimed?

A. Many variables affect the lime build up process including:

• Water temperature — the amount of lime accumulation during the same period of time will be nearly 2 times great if water is stored at 140 degrees F than at 120 degrees F. A 180° setting may accumulate seven times more lime — in a period of time — than at 140° setting.

• Volume of water— the more gallons flowing through the BTH, the more rapid the accumulation.

• Hardness — the harder the water the quicker lime build up occurs. 1 to 3.5 grains per gallons is “soft”, 3.5 to 7 grains per gallon is “moderate”, 7 to 10.5 grains per gallons is “hard” and

10.5+ grains per gallon is “very hard”. (An aspirin is about 5 grains. One grain is equal to 17.1 parts per million.)

A. Deliming should be done when a slight rumbling or popping sound is detected when the main

burner is on. Check for accumulation through the clean-out opening.

Q. What effect will lime build-up have on the BTH water heater?

A. One eighth inch of scale buildup on the heat exchanger may reduce efficiency as much as

22%: a % inch buildup, as much as 38%.

Less efficient heat transfer means more heat exchanger expansion/contraction stress and pre mature leakage. Because the heat transfer to the water is made through a (relatively) small diameter, coil type

exchanger tube, expansion and contraction as well as the shape of the exchanger greatly

reduces buildup on the heat transfer surface. The bottom of the tank should be checked for

dislodged accumulation.

Q. Anode rods (4) provide additional protection against corrosion. When should these be

replaced?

A. When large gauges or pits appear in the anodes, replace them.

Q. How often should the anodes be inspected?

A. Approximately every six months.

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BTH SERVICE HANDBOOK

ERROR CODES

CODE INDICATION

00 This is normal operation, 00 is displayed each time the heater is powered up.

Indicates the pressure switch circuit was not open during the prediagnostic system check when the proper state of the Draft Prover Switches are verified. The Blower Prover Switch is normally open, the circuit should therefore be open during the

prediagnostic system check at the beginning of each cycle. Check Blower Proving Switch for continuity with the blower off, there should be no continuity, check pressure switch wiring.

Indicates the heater faiied to light after 3 trials. Check ignitor, gas pressure, blower

speed reduction on BTH 250. Indicates the ECO is open. Check water temperature in tank, ECO will open at 202°

F and can be reset below 160° F. Indicates a Temperature Probe is open. Check both probes for proper resistance

and continuity. Indicates the Pressure Switch Circuit did not close after blower was energized.

Check normally open Blower Prover Switch operation, check normally closed

Blocked Outlet, Inlet, and Low Gas pressure (BTH 120 and 250 only) to ensure they remain closed. Check for blocked vent pipe (s) or if equivalent feet venting limits have been exceeded.

CODE #S

ABOVE

199

Indicates temperature sensed by probe(s) is out of bounds, reading is less than 30° F. Check resistance of temp probes, check water temperature in tank.

Indicates Ignition Reiay faiiure. Should be off and it is on. Try resetting, turn power off and on, if code remains, replace board.

Indicates temperature sensed by probe(s) is out of bounds. Reading is more than 220° F. Check resistance of temp probes, check water temperature.

Internai software or hardware errors, electrical line noise can cause erratic operation and these error codes. Try adding a “line fiiter” (available from electrical suppliers) to the 120 VAC power supply. If these errors codes persist or the control cannot be reset, replace the control board.

All these errors cause a “soft” lockout with the exception of 04 ECO, which is a “hard” lockout. Soft lockouts will reset automati cally after 60 minutes or if the reset button is pushed at any time. The ECO lockout, error code 04 will have to be manually reset by pushing the rest button after water in the tank has cooled below

160° F.

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BTH SERVICE HANDBOOK

SERVICE CHECKLIST

This is not intended to be and all-inclusive list of the problem that the Service Agent may encounter. Any item checked “no” on this list should be thoroughly investigated and corrective action taken, if required.

SERVICE AGENT: MODEL NUMBER: SERIAL NUMBER:

GAS

CHECK CLEARANCE (CIRCLE ANSWER)

TYPE —CHECK ONE NATURAL PROPANE

PROPER GAS VALUE VERIFIED

A. Are exterior clearances adequate?

B. Are interior clearances adequate?

Comments:

CHECK MAKEUP AIR REQUIREMENTS

A. Is the quality of make-up air adequate?

Comments:

--------------YES

INSTALLATION DATE:

SERVICE DATE:

LOCATION ADDRESS: PHONE ( )

yes yes

yes

no no

B. Is the quantity of make-up air adequate?

Comments:

GAS PRESSURE (FILL IN BLANK) — ALL UNITS ON.

A. Supply gas pressure_inches of W.C. (flowing)

B. Manifold gas pressure (main burner)_inches of W.C. (flowing)

Comments:

IV.

VENTING (CHECK) A. Acceptable equivalent footage

B. Proper material C. Proper exterior installation D. Condensate will drain

Comments:

V. WATER PIPING

Is the system properly sized? Is the system properly installed?

Are there any water leaks?

Does the installation have a recirculating system? If so, is it operational? SAFETYVI.

A. Air

If exhaust is blocked will unit lockout? If air intake is blocked will unit lockout?

Water Temperature

- Is the thermostat adjusted to the lowest acceptable temperature?

- Does the installation have a mixing valve?

- If so, is it operational?

- What is the outlet temperature of the mixing valve?

NOTE: To minimize the risk of scalding, the manufacturer recommends storing water at 120° F.

Is a properly rated temperature and pressure relief valve installed? Is there a properly installed expansion tank? Should there be? C. Electrical

Is the 120 VAC electrical powers supply properly wired? (including polarity) Are all the BTH control covers in place? Is the 120 VAC electrical power supply properly fused?

D. Flammables

Are flammable materials located in the area of the water heater? or air intake? Are flammable vapors located in the area of the water heater? or air intake?

E. Gas

If the gas supply is reduced or turned off will the unit turn off? Comments:

yes no

yes yes yes yes

yes yes yes yes yes

yes yes

yes yes yes yes

yes yes yes

yes yes

yes

no no no no

no no no no no

no no

no no no no

no no no

no no

[This service checklist may be photo copied to assist with BTH service calls.]

Technical Training Department

TC-044 Revision 6 42

A. O. Smith Water Products Co.

Page 44

ВТН SERVICE HANDBOOK

PARTS LISTS

/дЛ,, c 1ТТГ^ I

WATER PRODUCTS

COIVIPAM Y

COMMERCIAL WATER HEATER PARTS LIST

MODEL BTH -120, 150,199,250

SERIES 970 & 973

Page 45

BTH SERVICE HANDBOOK

PARTS LISTS

BTH 1200-250

EXHAUST ELBOW & VENT

KIT FARTS

'%■ <>.. ■

63-^-N^ 62

60 I

181617

192815 182167

( >1

CLEANOUT ASSEMBLY

Technical Training Department

TC-044 Revision 6 44

CONTROL PANEL

17a

A. O. Smith Water Products Co.

Page 46

BTH SERVICE HANDBOOK

BURNER ASSEMBO^

PARTS LISTS

GAS VALVE

75 70

f h

"t '

A. O. Smith Water Products Co.

Technical Training Department

TC-044 Revision 6

Page 47

BTH s E R V 1 C E HAN D B 0 0 K

ARTS

LISTS

DESCRIPTION

BTH 120

970

BTH 120 973

BTH 150 970

BTH 150

973

BTH 199 970

BTH 199 973

BTH 250 970

1 Cleanout Cover If? 1260 181260 181260 181260 181260 181260 181260 2

Cleanout Gasket 99038 99038 99038 99038 99038 99038 99038

3 Cleanout Plato 4

Top Cover. Left 193885 193885 193885 193885 193885 193885 193885

99037 99037 99037 99037 99037 99037 99037

5 Top Cover, Right 193886 193886 193886 193886 193886 193886 193886 6 Top Cover, Back, Nat.

Top Cover. Back. Prop. 193887 193887 193887 193887 193887 193887

193887 193887 193887 193887 193887 193887 193887

7 Drain Valve 26273-6 26273-6 26273-6 26273-6 26273-6 26273-6 26273-6 8 T & P Roliel Valve 99465-7 99465-7 99465-7 99465-7 99465-7 99465-7 192467 9 Upper Temp. Probe w/ECO 192606 192606 192606 192606 192606 192606

192606

10 Lower Temp. Probe 192609 192609 192609 192609 192609 192609 192609 11

Anode, Alum. Alloy (4)

13 ii Manual*

:yclone xhe bth — control

Board, Display Panel

Control Board & Cable

183523-33 183523-52 183523-52 183523-52 183523-52 183523-52 183523-52 196145

196145 196145 196145 196145 196145 196145

PANEL

192622-1 192622-1 192622-1 192622-1 192622-1 192622-1 192622-1 193822 193822 193822 193822 193822 193822 193822

Assem. (includes 17a)

17a

Cable Assem., Control Board

192623 192623 192623 192623 192623 192623 192623

to Display Board

20 Display Panel Label 194203 194203 194203 194203 194203 191203 194203 21

Panel, rronl 193884

193884 193884 193884 193884 193884 193884

23 On/Off Switch 193243 193243 193243 193243 193243 193243 193243 24 Cablo Assembly. Lino Power 19-1261

194261 194261 194261 194261 194261 194261

BTH 120 - 250 TOP COVER CONTROLS

25 Blocked Inlet Switch, Natural

193293 193363 193363 193361

Gas

25 Blocked Inlet Switch, Propane

193356 193355

195012

Gas

26 Blocked Outlet Switch, Natu

193294 193362 193364 193357

ral Gas

26 Blocked Outlet Switch, Pro

193357

pane Gas

27 Blower Prover Switch

194706 194706 194706 194706

28 Blower/Motor Assembly 194675 194675 194673 194675 194673 194675 29 Inlet Flange Assembly w/

192886-1 192886-1 192886-1 192886-1 192886-1 192886-1 192886-1

194706 194706

194706 194674

Hose Barb

30 Intake Assembly 192815 192815 192815 192815 192815 192815 194116 34 Cable Assembly, Low Voltage 193246 193246 193246 193246 193246 193246 193246 35 Wire Assembly, Air Flow

192802 192802 192802 192802 192802 192802 192802

36 Bracket, Blower Mounting 192482 192482 192482 192482 192482 192482 192482 37

Tube, Pressure 193738-8 193738-8 193738-8 193738-8 193738-8 193738-8 193738-8

38 Tube, Pressure 193738-22 193738-22 193738-22 193738-22 193738-22 193738-22 193738-22 41

Tube, Air 192469-10 192469-10 192469-10 192469-10 192469-10 192469-10 192469-10

43 Transformer, 120V-24V,60

192608 192608 192608 192608 192608 192608 192608

Hz,20 VA

Technical Training Department TC-044 Revision 6

A. O. Smith Water Products Co.

Page 48

B T H s E R V 1 C E HAN D B 0 0 K

ARTS LISTS

rvCer'DIDXir^M

BTH 120 BTH 120 BTH 150 BTH 150 BTH 199 BTH 199 BTH 250

970 973

970 973 970 973 970

44 li Wire Assembly, Air Flow 192802-1 192802-1 192802-1

1 Switch

GAS VALVE

48 1 Switch, Low Gas Pressure,

191149-5

Natural

191149-4

Propane

50 Gas Valve. Natural Gas 192966 50 1 Gas Valve, Propane Gas

192967

192797 192797 192454

192454-1

EXHAUST ELBOW, VENT KIT PARTS

51 1 Adapter, Hose Fitting 192472 192472 192472 192472 192472 192472 192472 52 Elbow 90

192473 192473 192473 192473 192473 192473 192473

53 1 Nipple, Close 194558 194558 194558 194558 194558 194558 194558 54

Plug, Hex

194560 194560 194560 194560 194560 194560 194560

55 1 Tee 194559 194559 194559 194559 194559 194559 194559 56 Tubing 191746-72 191746-72 191746-72 191746-72 191746-72 191746-72 191746-72 57

1 Connector, Exhaust 192636 192636 192636 192636 192636 192636 192636

VENT KIT PARTS

60 1 Elbow w/Screen 192815 192815 192815 192815 192815 192815 192815 61 Elbow. 45 X 3.5" 181901 181901 181901 181901 181901 181901 181901 62 1 Screen 181662 181662 181662 181662 181662 181662 181662 63 1 Intake Vent Terminal Assy. 182167 182167 181617 181617 181617 64 ii Wall Plates (2 Req’d.) 181557 1815' ■ 181557 181557 181557 181557 181557 65 1 Silicone Sealer, 2 oz. Tube

181564

1815t

181564 181564 181564 181564 181564

BURNER — ASSEMBLY

Burner

Burner for (BTH - 120, 150,

196162 19611 196ie 196K

196162-1

1 196162-1

196162-1

*1991973

Ignitor Assembly 192638 192638

69 Air Restrictor — Natural Gas 192450-3 192450-1 192450

192638

192638 192638 192638

192450-2

69 1 Air Restrictor — Propane Gas i 192450-5 192450-5 192450 70 1 1 lose Barb 192800-1 192800-1 192800-1 192800-1 192800-1 192800-1 192800-1 71 1 Flame Rod Assembly 192478 192478 192478 192478 192478 192478 192478 73 Orifice — Natural Gas 192477-3

192477-1 192477 192477-2

73 Orifice — Propane Gas 192477-6 192477-5 192477-10 74

Orifice Holder

192447 192447 192447 192447 192447 192447 192447

75 Gasket 192331 192331 192331 192331 192331 192331 192331 76 5/16” X 7/8" Socket Head Cap

192515-2

192515-2 192515-2

1 192515-2

192515-2 192515-2

192515-2

Screw (4 Req’d.)

*Not illustrated.

NOTE: Shaded parts are recommended stock items for emergency replacement. Consider gas used in

your area only. Standard hardware items may be purchased locally.

Technical Training Department

TC-044 Revision 6

Page 49

Z^o SEfflDUE]

ВТН SERVICE HANDBOOK

PARTS LISTS

WATER PRODUCTS

COMPANY

COMMERCIAL WATER HEATER PARTS LIST

CYCLONE XHE MODEL BTH -120

SERIES 966/967

(PARTIAL PARTS LISTING)

Technical Training Department TC-044 Revision 6

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

PARTS INFORMATION

PHONE: 1-800-433-2545

FAX: 1-800-433-2515 -WWW.AOSMITHWATERHEATERS.COM

A. O. Smith Water Products Co.

Page 50

ВТН SERVICE HANDBOOK

PARTS STS

CYCLONE XHE® MODEL

BTH -120 WATER HEATER PARTS LIST (PARTIAL)

SERIES 966/967

ITEM DESCRIPTION BTH -120

ii Anode 043817-029

2 ii Panel, Front 193884-000 5 Panol. Loft Sido 193885-000

6 Panol. Right Sido 193888-000 20 Condonsalo I loso 181864-072 22 Barb. Hose

24 Exhaust Torminal 192815-000

25 II Intake Terminal 192815-000 27 II Plate, Pressure 099037-000 28 Gasket 099038-000 29 I Valve, Relief 192467-000 30 Clamp. I loso. Nylon Snap 191794-001 33 II Panel, Back 193887-000

36 ii Instruction Manual 194119-000

181863-000

A. O. Smith Water Products Co.

Technical Training Department

TC-044 Revision 6

Page 51

ВТН SERVICE HANDBOOK

PARTS LISTS

CYCLONE XHE® MODEL

BTH -120 CONTROLS PART LIST — SERIES 966/967

966 = NATURAL GAS 967 = PROPANE GAS

ITEM DESCRIPTION

I Transformer 192608-001

BTH-120

2 1 Control Board 193822-000 3 E.C.O. Tomporaluro Probo 192606-000 4 Blower Proving Air Switch 193295-000 7

Blower Assembly

193341-000

8 Igniter Assembly 192638-000 9 I Cable to Control Display Board 192623-000

10 Board. Display Panel 192622-001

11 Blocked Outlet Proving Switch 193294-000

Temperature Probe, Lower 192609-000

1 Tubing, Pressure

192024-002

15 I Tubing, Pressure 192024-006 16 I Tubing, Connector 192152-000 17 Swilch-On.^Olf 193243-000 18 I Low Nat. Gas Pressure Switch 191149-001 19 I Low Prop. Gas Pressure Switch 191149-004 20 Blocked Inlot Switch 193293-000

Part numbers in shaded cells are recommend stock items for emer gency replacement.

Technical Training Department TC-044 Revision 6

A. O. Smith Water Products Co.

Page 52

ВТН SERVICE HANDBOOK

PARTS LISTS

CYCLONE XHE® MODEL

BTH -120 BURNER & BLOWER PARTS LIST — SERIES 966/967

ITEM DESCRIPTION BTH-120

Nat Burner 194114-003

1 Prop Burner

Ignitor Assembly 192638-000

194114-006

6 Barb. I lose. 3. IK" 181863-000 7 Flame Rod Assembly

192478-000

9 Nat Orifice 192477-003

9 Prop Orifice 192477-006 13 Valve. Nat Gas 192966-000 13 Valve. Prop Gas 192967-000 14

II Blower 193341-000

15 Tubo. Air 192469-010 18 Flange Assembly. Inlet 192886-001 19 Low Nat. Gas Pressure Switch 191149-001 19 Low Prop. Gas Pressure Switch 191149-004

Part numbers in shaded cells are recommended stock items for emer gency replacement.

A. O. Smith Water Products Co.

Technical Training Department

TC-044 Revision 6

Page 53

ВТН SERVICE HANDBOOK

PARTS LISTS

WATER PRODUCTS

COMPANY

COMMERCIAL WATER HEATER PARTS LIST

CYCLONE XHE MODEL BTH -150, BTH -199

SERIES 966 & 967

(PARTIAL PARTS LISTING)

EXHAUST TERMINAL

DIRECT VENT INTAKE TEE

Technical Training Department TC-044 Revision 6

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

PARTS INFORMATION

PHONE; 1-800-433-2545

FAX: 1-800-433-2515 • WWW.AOSMITHWATERHEATERS.COM

CLEANOUT ASSEMBLY

A. O. Smith Water Products Co.

Page 54

ВТН SERVICE HANDBOOK

PARTS STS

CYCLONE XHE® MODELS

BTH -150 & BTH -199 SERIES 966 & 967

CONTROLS PARTS LIST (PARTIAL)

ITEM DESCRIPTION

1 Anode

Panel, rrent 194884-000 194884-000 194884-000 194884-000

BTH -150 NATURAL (966)

0435517-053

PROPANE

(967)

043817-053

BTH -199 NATURAL (966)

043817-053

PROPANE (967)

043817-053

3 Burner Assembly 194114-001 194114-005 194114-000 194114-004 4 Blower

193354-000 193354-000 193354-000 193354-000

5 Panel. Loft Side 193885-000 193885-000 193885-000 193885-000 6 Panel. Right Side 193886-000 193886-000 193886-000 193886-000

19 Valve. Drain 026273-004 026273-001

026273-004 026273-004

20 Condensate I lose 191746-072 181894-072 191746-072 181894-072 22

Barb. Hose 181863-000 181863-000 181863-000 181863-000

24 Exhaust Terminal 192815-000 192815-000 192815-000 192815-000 25 Direct Vent Kit 193202-000 193202-000 193202-000 193202-000 27

Plate, Pressure 099037-000 099037000 099037-000 099037-000

28 Gasket 099038-000 099038-000 099038-000 099038-000 29 Valve. Relief 192467-000 192467-000 192467-000 192467-000

33‘ Screen. Exhaust 181662-000 181662-000 181662-000 181662-000

Panel. Back 193887-000 193887-000 193887-000 193887-000

Gasket 192331-000 192331-000 192331-000 192331-000

*Not Illustrated

A. O. Smith Water Products Co.

Technical Training Department

TC-044 Revision 6

Page 55

ВТН SERVICE HANDBOOK

PARTS STS

CYCLONE XHE® MODELS

BTH -150 & BTH -199 SERIES 966 & 967 CONTROLS PARTS LIST

BTH -150 BTH - 199

ITEM DESCRIPTION

NATURAL PROPANE NATURAL PROPANE

(966) (967) (966) (967)

1 I Transformer 192K0f?-001 192608-001 192608-001 192608-001 2

Control Board 193822-000 193822-000 193822-000 193822-000

3 E.C.O.. Upper Probe 192Й0Й-000 192606-000 192606-000 192606-000

Blower Proving Switch 193295-000 193295-000 193295-000 193295-000

7 I Blower Assembly 192880-000 192880-000 192880-000 192880-000 8 Ignitor Assembly 192638-000 192638-000 192638-000 192638-000 9 Cable to Control Display Board 192623-001 192623-000 192623-000 192623-000

10 I Board, Display Panel 192622-001 192622-001 192622-001 192622-001

I Blocked Outlet Switch 193362-000 193357-000 193364-000 193357-000

12 Tomperatiiro Probe. Lower 192609-000 192609-000 192609-000 192609-000 14

Tubing. Pressure 192024-006 192024-0006 192024-006 192024-006

15 Tubing. Pressure 192024-004 192024-004 192024-004 192024-004 16 Connector. Tubo 192152-000 192152-000 192152-000 192152-000 17

I Blocked Inlet Switch 193363-000 193355-000 193363-000 193356-000

18 ON.-OFF Switch 193243-000 193234-000

Technical Training Department

TC-044 Revision 6 54

193234-000

A. O. Smith Water Products Co.

Page 56

ВТН SERVICE HANDBOOK

PARTS STS

CYCLONE XHE® MODELS

BTH -150 & BTH -199 SERIES 966 & 967 BURNER & BLOWER PARTS LIST

BTH-150 BTH-199

ITEM DESCRIPTION NATURAL

(966)

I Burner Assembly 1941И-001 194114-005 194114-000

PROPANE NATURAL PROPANE

(967)

(966)

(967)

194114-004

2 Ignitor Assembly 192e3f?-000 192638-000 192638-000 192638-000 7

Flame Rod Assembly 192478-000 192478-000 192478-000 192478-000

9 Ori rice 192477-001 192477-005 192477-000

192477-004

13 Valve, Gas 192797-000 192454-001 192797-000 192454-001 14

Blower 193354-000 193354-000 193354-000 11 193354-000

15 Tubo. Air 1924Й9-010 192469-010 192469-010 192469-010 18 Flange. Inlet 192641-001 192886-001 192641-001 1192886-001

A. O. Smith Water Products Co.

Technical Training Department

TC-044 Revision 6

Page 57

ra. SKanTrra

BTH SERVICE H A N D B O O K

PARTS LISTS

WATER PRODUCTS

COMPANY

CYCLONE XHE^ MODEL BTH - 250

COMMERCIAL WATER HEATER PARTS LIST

SERIES 966

(PARTIAL PARTS LISTING)

Technical Training Department TC-044 Revision 6

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

PARTS INFORMATION

PHONE: 1-800-433-2545

FAX; 1-800-433-2515 • WWW.AOSMITHWATERHEATERS.COM

A. O. Smith Water Products Co.

Page 58

ВТН SERVICE HANDBOOK

PARTS LISTS

CYCLONE XHE® MODEL

BTH - 250 WATER HEATER PARTS LIST (PARTIAL)

SERIES 966

ITEM DESCRIPTION BTH - 250

Anode

Panel, Front 194884-000

Burner Assembly

Blower 193203-000

5 Panel, Left Side 193885-000 6 Panel, Right Side 193886-000

Temperature Probe, Lower 192609-000

19 Valve, Drain 026273-004 20 Condensate Hose 181894-072 22

Barb, Hose 181863-000

Exhaust Terminal 192815-000

25 Direct Vent Intake Terminal 181762-000 27 Plate, Pressure 099037-000 28 Gasket 099038-000 29

Valve, Relief 192467-000

33 Panel, Back 193887-000

043817-053

194114-002

Part numbers in shaded cells are recommended stock items for emergency replacement.

A. O. Smith Water Products Co.

Technical Training Department

TC-044 Revision 6

Page 59

ВТН SERVICE HANDBOOK

PARTS STS

CYCLONE XHE® MODELS

BTH - 250 CONTROLS PARTS LIST — SERIES 966

ITEM DESCRIPTION BTH - 250

1 Transformer

192608-001

2 Control Board 193822-000 3 II E.C.O./Temperature Probe 192606-000 4 II Blower Proving Air Switch 193295-000 7

1 Blower Assembly 193203-000

8 Ignitor Assembly

192638-000

g Cable to Control Display Board 192623-000

10 II Board, Display Panel 192622-001

11 Bloeked Outlet Proving Switeh 193357-000

Temperature Probe. Lower 192609-000

14 Tubing. Pressure 192024-001 15 II Tubing, Pressure 192024-006

Tubing. Connector

192152-000

17 Blower Speed Redueing Panel 192987-000 18 Low Gas Pressure Switch 191149-001 19 Blocked Inlet Switeh 193361-000

Switch-On-Off 193243-000

Part numbers in shaded cells are recommended for

stock items for emergency replacement.

Technical Training Department TC-044 Revision 6

A. O. Smith Water Products Co.

Page 60

ВТН SERVICE HANDBOOK

PARTS LISTS

CYCLONE XHE® MODELS

BTH - 250 BURNER & BLOWER PARTS LIST — SERIES 966

ITEM DESCRIPTION BTH-250

1 Burnor 194114-002 2 Icjnitor Assembly 192638-000 7 Flame Rod Assombly 192478-000

9 Orifice 192477-002 13 Valve. Gas 192464-000 14 Blower 193203-000 15 Tube. Air 192469-010 18 Flange Assembly. Inlel 192886-001 19 .Low Gas Pressure Switch i 191149-001

Part numbers in shaded cells are recommended

for stock items for emergency replacement.

A. O. Smith Water Products Co.

Technical Training Department

TC-044 Revision 6

Page 61

ВТН SERVICE HANDBOOK

PARTS LISTS

ё^РХППТгГЯ

WATER PRODUCTS

COMPANY

CYCLONE XHE MODEL BTH -150, BTH-199

COMMERCIAL WATER HEATER PARTS LIST

SERIES 960

(PARTIAL PARTS LISTING)

EXHAUST TERMINAL

DIRECT VENT TERMINAL

Technical Training Department TC-044 Revision 6

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

PARTS INFORMATION

PHONE; 1-800-433-2545

FAX: 1-800-433-2515 •WWW.AOSMITHWATERHEATERS.COM

CLEANOUT ASSEMBLY

A. O. Smith Water Products Co.

Page 62

ВТН SERVICE HANDBOOK

PARTS LISTS

CYCLONE XHE® MODEL

BTH -150 & BTH -199 WATER HEATER PARTS LIST — SERIES 960

ITEM DESCRIPTION BTH -150 BTH -199

1 I

I Anode 043817-053 043817-053

I Cover, Jacket 192664-000 192664-000

3 I Burner Assembly 192417-001 192417-001

4 iI Motor, Blower

5 I Cage, Housing 192420-000 192420-000

6 I Bracket, Control Panel 192716-000 192716-000 17 II Temperature Probe, Lower 192609-000 20 I Condensate Hose 191746-072 191746-072 22

I Barb, Hose 181863-000 181863-000

24 I Exhaust Terminal 181901-000 181901-000 25 I Direct Vent Kit 182167-000 182167-000 27 I Plate, Pressure 099037-000 099037-000 28 I Gasket 099038-000 099038-000 29 I Valve, Relief 191617-000

192880-000 192880-000

192609-000

191617-000

A. O. Smith Water Products Co.

Technical Training Department

TC-044 Revision 6

Page 63

ВТН SERVICE HANDBOOK

PARTS STS

CYCLONE XHE® MODEL

BTH -150 & BTH -199 WATER HEATER PARTS LIST — SERIES 960

ITEM DESCRIPTION

BTH-150 BTH -199

1 II Transformer 19260t5-000 192508-000

Control Board 192624-000 192624-000

3 E.C.O..TomporaUiro Probo 192606-000 192506-000 4

Blower Proving Air Switch 192811-000 192811-000

5 Low Voltage Cable Assembly 192605-000 192805-000 6 Lino Voltage Cable Assembly 192607-000 192607-000 7

Blower Assembly 192468-000 192468-000

Igniter Assembly

192638-000 192538-000

9 Cable to Control Display Board 192623-000 192623-000

10 Board. Display Panol 192622-001 192522-001

11 Blocked riue Proving Switch

192810-000 192810-000

12 Temporature Probo. Lower 192609-000 192509-000 13 li Wire Assembly, Air Flow Switch 192802-000 192302-000 14

Tubing. Pressure 192024-014 192024-014

15A Tubing. Pressure 192024-004 192024-004 16A

Tubing. Pressure 192024-004

192024-004

17A Tubing. Pressure 192024-008 192024-008 18A

II Connector, Tube 192152-000 192152-000

19 II Tubing, Pressure 192024-008 192024-008

Technical Training Department

TC-044 Revision 6 62

A. O. Smith Water Products Co.

Page 64

ВТН SERVICE HANDBOOK

PARTS LISTS

CYCLONE XHE® MODEL

BTH -150 & BTH -199 BURNER & BLOWER PARTS LIST — SERIES 960

ITEM 1 DESCRIPTION

1 1 Burner

1 Igniter Assembly 192638-000 192638-000

BTH-150 BTH -199

192416-000

4 1 Air Deflector 192414-000 192414-000 5 1 Air Restrictor 192450-001 192450-001 6 1 Barb, Hose, 3/16 ’ 192800-000 192800-000 7

1 Flame Rode Assembly 192478-000 192478-000

9 ^ Orifice 192477-001 192477-000

1 Orifice Holder 192447-000 192447-000

13 1 Valve, Gas 192797-000 192797-000 14 1 Blower

192468-000

15 1 Tube, Air 192469-000 192469-000 17 1 Bracket, Blower Mounting 192482-000 192482-000 18

1 Flange Inlet 192641-000

192641-000

A. O. Smith Water Products Co.

Technical Training Department

TC-044 Revision 6

Page 65

ВТН SERVICE HANDBOOK

PARTS LISTS

аКЛПТгГЯ

WATER PRODUCTS

COMPANY

CYCLONE XHE® MODEL BTH - 250

COMMERCIAL WATER HEATER PARTS LIST

SERIES 962

(PARTIAL PARTS LISTING)

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

PARTS INFORMATION

PHONE: 1-800-433-2545

FAX: 1-800-433-2515 -WWW.AOSMITHWATERHEATERS.COM

Technical Training Department

TC-044 Revision 6 64

A. O. Smith Water Products Co.

Page 66

ВТН SERVICE HANDBOOK

PARTS LISTS

CYCLONE XHE® MODEL

BTH - 250 WATER HEATER PARTS LIST (PARTIAL)

SERIES 962

ITEM DESCRIPTION BTH - 250

I Anode 043817-004

I Cover, Jacket 192664-000

3 I Burner Assembly 192417-003 4 I Motor, Blower 5 I Cage, Housing 192420-000

6 I Bracket, Control Panel 192716-000 17 I Temperature Probe, Lower 192609-000 20 I Condensate Hose 181864-000 22 I Barb, Hose 181863-000

Exhaust Vent Terminal 192815-000

25 I Direct Vent Intake Tee 27 I Plate, Pressure 099037-000 28 I Gasket 099038-000 29 I Valve, Relief

193203-000

181762-000

192467-000

Part numbers in shaded cells are recommended

stock items for emergency replacement.

A. O. Smith Water Products Co.

Technical Training Department

TC-044 Revision 6

Page 67

ВТН SERVICE HANDBOOK

PARTS STS

CYCLONE XHE® MODELS

BTH - 250 CONTROLS PARTS LIST — SERIES 962

Technical Training Department TC-044 Revision 6

ITEM DESCRIPTION BTH - 250

1 Transformer 192K0f?-001

I Control Board 192624-000

3 E.C.O.-Tomporaluro Probe 192606-000 4 Blowor Proving Air Switch 193221-000 5 Low Voltage Cable Assembly 192605-000 6 Lino Voltage Cable Assembly 192607-000 7

Blower Assembly 193203-000

8 Igniter Assembly 192638-001 9 Cable to Control Display Board 192623-000

10 I Board, Display Panel 192622-000

11 I Blocked Outlet Proving Switch 192946-000

I Temperature Probe, Lower 192609-000

13 Wire Assembly. Air Flow Switch 192802-001 14

Tubing. Pressure

192024-002

15 Tubing. Pressure 192024-006 16 Tubing. Connector 192152-000 17

Blower Speed Reducing Panel 192987-000

18 Low Gas Pressure Switch 193222-001 19 I Blocked Inlet Switch 192947-000 20 Wire Assembly. Air Flow Switch 192802-000

21 Switch-On.'Olf 192699-000

A. O. Smith Water Products Co.

Page 68

ВТН SERVICE HANDBOOK

PARTS LISTS

CYCLONE XHE® MODELS

BTH - 250 BURNER & BLOWER PARTS LISTS — SERIES 962

ITEM 1 DESCRIPTION

1 1 Burner

1 Igniter Assembly

BTH-250

192416-000 192638-000

3 1 Rivet, Blind, 1/8” Dia 316 SS 192730-000 4 I Air Deflector 5 I Air Restrictor

192414-000 192450-002

6 I Barb, Hose, 3/16” 192800-000 7 1 Flame Rod Assembly 9 ^ Orifice

1 Orifice Holder 192447-000

192478-000

192477-002

13 1 Valve, Gas 192454-000 14 1 Blower 193203-000 15 1 Tube, Air 17

1 Bracket, Blower Mounting 192482-000

192469-010

18 1 Flange Assembly, Inlet 192886-000 19 1 Low Gas Pressure Switch 191149-001

Part numbers in shaded cells are recommended stock items for emergency replacement.

Technical Training Department

TC-044 Revision 6

Page 69

ВТН SERVICE HANDBOOK

PARTS LISTS

WATER PRODUCTS

COMPANY

/д

¿5?

COMMERCIAL WATER HEATER PARTS LIST

CYCLONE XHE MODEL BTH -150 & BTH -199

SERIES 962

(PARTIAL PARTS LISTING)

EXHAUST TERMINAL

DIRECT VENT TERMINAL

CLEANOUT ASSEMBLY

Technical Training Department TC-044 Revision 6

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

PARTS INFORMATION

PHONE: 1-800-433-2545

FAX: 1-800-433-2515 -WWW.AOSMITHWATERHEATERS.COM

A. O. Smith Water Products Co.

Page 70

ВТН SERVICE HANDBOOK

PARTS STS

CYCLONE XHE® MODEL

BTH -150 & BTH -199 WATER HEATER PARTS LIST — SERIES 962

ITEM DESCRIPTION

li Anode 0-13817-053 0-13817-053

2 Cover. Jacket

BTH -150 BTH -199

192664-00 192664-000

3 li Burner Assembly 192417-001 192417-001 4 Motor. Blower

192880-000 192880-000

5 Cage. I lousing 192420-000 192420-000

6 I Bracket, Control Panel 192716-000 192716-000 17 Temperature Probe. Lower 192609-000 192609-000 20 Condensate I lose 191746-072 191746-072 22

Barb. Hose 181863-000 181863-000

24 I Exhaust Terminal 181901-000 181901-000 25 Direct Vent Kit 182167-000 182167-000 27 Plate. Pressure 099037-000 099037-000 28 I Gasket 099038-000 099038-000 29 Valve. Roliel

191617-000

Part numbers in shaded cells are recommended stock items for emer gency replacement.

A. O. Smith Water Products Co.

Technical Training Department

TC-044 Revision 6

Page 71

ВТН SERVICE HANDBOOK

PARTS LISTS

CYCLONE XHE® MODELS

BTH -150 & BTH -199 CONTROL PARTS LIST — SERIES 962

TO BLOWER

Technical Training Department TC-044 Revision 6

ITEM DESCRIPTION BTH -150 BTH -199

1 Transformer 192608-000 192608-000

2 1 Control Board 192624-000 192624-000 3 E.C.O/Temperature Probe

192606-000

4 1 Blower Proving Air Switch 193221-000 193221-000 5 1 Low Voltage Cable Assembly 192605-000 192605-000 6 1 Line Voltage Cable Assembly 192607-000 192607-000 7

1 Blower Assembly 192468-000 192468-000

8 1 Igniter Assembly 192638-000 192638-000 9 1 Cable to Control Display Panel 192623-000 192623-000

10 1 Board, Display Panel 192622-000 192622-000

11 1 Blocked Flue Proving Switch 192878-000 192878-000

1 Temperature Probe, Lower 192609-000 192609-000

1 Wire Assembly, Air Flow Switch

192802-000 192802-000

14 1 Tubing, Pressure 192024-014 192024-014 15 1 Tubing, Pressure 192024-004 192024-004 16 1 Connector, Tube 17

1 Blocked Inlet Proving Switch 192882-000 192882-000

192152-000

18 1 Switch-On/Off 192699-000 192699-000

Part numbers in shaded cells are recommended stock items for emer gency replacement.

A. O. Smith Water Products Co.

Page 72

ВТН SERVICE HANDBOOK

PARTS LISTS

CYCLONE XHE® MODELS

BTH -150 & BTH -199 BURNER & BLOWER PARTS LIST

SERIES 962

ITEM DESCRIPTION BTH -150 BTH -199

1 Biirnor

192416-000 192416-00

2 Ignitor Assembly 192638-00 192638-000 4 Air Deflector

192414-000 192414-000

5 Air Restrictor 192450-001 192450-001 6 Barb. I lose. ;V16" 192800-000 192800-000 7

name Rod Assembly 192478-000 192478-000

9 Orilico 192477-001 192477-001 10 Orifice Holder 192447-000 192447-000 13 Valve. Gas il loneywolli 192797-000 192797-000

Blower 192468-000 192468-000

15 Tube, Air 192469-010 192469-010 17 Bracket, Blower Mounting 192482-000 192482-000

Part numbers in shaded cells are recommended stock items for emergency replacement.

Technical Training Department

TC-044 Revision 6

Page 73

NOTES

BTH SERVICE HANDBOOK

PARTS STS

Technical Training Department

TC-044 Revision 6 72

A. O. Smith Water Products Co.

Page 74

Visit the “Information Central” link of www.hotwater.com for a listing of

available Service Handbooks.

For additional information contact:

A. O. Smith Water Heaters 500 Tennessee Waltz Parkway Ashland City, TN 37015

1-800-527-1953

www.hotwater.com

A.(XSmith

Water Heaters

Part No. TC-044R6

A.O. Smith 960 through, 967 through User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

Extra-High Thermal Efficiency

TABLE OF CONTENTS

INTRODUCTION

INSTALLATION

DIRECT VENTING

VENTING CONFIGURATIONS

VENTING MATERIALS

CONCENTRIC VENT TERMINATION

VENTING CLEARANCES

MAKE-UP AIR Vertical Ducts

OPERATION

To View Or Change Temperature Settings

DISPLAY CIRCUIT BOARD

IGNITION CIRCUIT BOARD

TROUBLESHOOTING

LOWER

TEMPERATURE PROBE PLUG

AMBIENT ROOM AIR PRESSURE

COMPONENT INFORMATION

PRESSURE SWITCH LAYOUT PRESSURE SWITCH WIRING

WIRING DIAGRAMS

SERVICE AIDS

NOTES:

QUESTIONS AND ANSWERS

Q. When should BTH’s be delimed?

ERROR CODES

SERVICE CHECKLIST

CYCLONE XHE® MODEL

CYCLONE XHE® MODEL

BTH -120 CONTROLS PART LIST — SERIES 966/967

CYCLONE XHE® MODEL

BTH -120 BURNER & BLOWER PARTS LIST — SERIES 966/967

CYCLONE XHE® MODELS

BTH -150 & BTH -199 SERIES 966 & 967 CONTROLS PARTS LIST

CYCLONE XHE® MODELS

BTH -150 & BTH -199 SERIES 966 & 967 BURNER & BLOWER PARTS LIST

CYCLONE XHE® MODEL

BTH - 250 WATER HEATER PARTS LIST (PARTIAL)

SERIES 966

CYCLONE XHE® MODELS

BTH - 250 BURNER & BLOWER PARTS LIST — SERIES 966

CYCLONE XHE® MODEL

BTH -150 & BTH -199 WATER HEATER PARTS LIST — SERIES 960

CYCLONE XHE® MODEL

BTH -150 & BTH -199 WATER HEATER PARTS LIST — SERIES 960

CYCLONE XHE® MODEL

BTH -150 & BTH -199 BURNER & BLOWER PARTS LIST — SERIES 960

CYCLONE XHE® MODEL

BTH - 250 WATER HEATER PARTS LIST (PARTIAL)

SERIES 962

CYCLONE XHE® MODELS

BTH - 250 BURNER & BLOWER PARTS LISTS — SERIES 962

CYCLONE XHE® MODEL

BTH -150 & BTH -199 WATER HEATER PARTS LIST — SERIES 962

CYCLONE XHE® MODELS

BTH -150 & BTH -199 CONTROL PARTS LIST — SERIES 962

CYCLONE XHE® MODELS

BTH -150 & BTH -199 BURNER & BLOWER PARTS LIST

SERIES 962

NOTES