A O Smith 120 Trough 500 Handbook NAME

120trough500 0c48242d-3c83-4152-90f5-c2442a241ec6 A.O. Smith Water Heater 120 trough 500 User Guide |

2015-01-05

: A-O-Smith A-O-Smith-120-Trough-500-Handbook-162762 a-o-smith-120-trough-500-handbook-162762 a-o-smith pdf

Open the PDF directly: View PDF .
Page Count: 55

BTR HANDBOOK
Q: How much electrical power is required for a BTR water heater?
NAME

BTR TANK TYPE HEATERS

SERVICE HANDBOOK

A.O. Smith Water Products Service Handbook

BTR HANDBOOK

TABLE OF CONTENTS

PAGE PAGE

Troubleshooting (continued)

Introduction 1-2 Troubleshooting the Efflkal 30-31

Wire Harness Test 32

Installation IID Module 33

Clearances 3-4 Pilot Spark 34

Air Requirements 5-9 Pilot Valve 35-36

Contaminated Air 10 Main Burner Test 37

Flammable 10 Flame Rectification 38

Gas Pressure 11 IID Module 39

Gas Valve 12 Main Gas Valve 40-41

Venting 13-15

Wiring Schematics

Natural and Propane Gas 42

Sequence of Operation

Mechanical 16 Service Charts 43

Electrical 17-18

General Questions & Answers 44

Troubleshooting

Transformer 19 Parts List 45-50

High Limit 20-21

Damper (on Standby) 22 Component Part Information 51

PC Board 22-23

Thermostat 24 Service Check List 52-53

Damper (call for heat) 25-26

Effikal Damper 27 Comments 54

Effikal Harness Test 28

Normal Operation 28-29

BTR WORKBOOK INTRODUCTION

This service handbook is designed to aid in servicing and troubleshooting A.O. Smith BTR water heaters in

the field. 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 common questions encountered in the

operation of the BTR 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

installation manual accompanying the product. This handbook contains supplemental information to the BTR

installation and operation manual.

BTR TANK TYPE HEATERS

SERVICE HANDBOOK

A.O. Smith Water Products Service Handbook

Qualifications: 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 testing skills are required.

Tools Required:

• Phillips head screwdriver

• standard screwdrivers

• a 3/8 and 7/16 inch open end wrench

• setofmarkeddrillbits

• an electrical multimeter tester capable of measuring continuity

• gas pressure gauge or manometer (gauge - AOS pt. no. 8099-2)

• water pressure gauge (AOS pt. no. 4798)

• thermometer (AOS pt no. 4870 - range 0 - 220 degree F)

• 1/2 inch socket with extension for removal of the clean out cover,

• 1 1/16 inch socket with extension for anode removal.

MISC: TC-043 Revision 1 vs. TC-043

Revision 1:

• Adds Additional model’s information.

• Adds cover statement this Handbook’s also a Service Handbook for many BTC Models.

• Includes Power vent kit information.

• Includes BTR/C-500 gas valve information.

• Updated Damper illustrations.

Revision2:

• Revised Part Numbers on Page 15

Revision 3:

• Adds information unique to the Efflkal damper equipped (Series 110, 111 and

Retrofit) models

BTR TANK TYPE HEATERS

SERVICE HANDBOOK

A.O. Smith Water Products Service Handbook

INSTALLATION

This portion of the handbook will review some often overlooked installation

considerations, taking note of necessary installation requirements for the BTR 120

through 500 model heaters. The installation manual covers most of these items in detail.

Clearance to Combustibles Table

MODEL A B C

120 - 200 1” (2.54CM) 1” (2.54CM) 1” (2.54CM)

250 - 305 2” (5.08CM) 2” (5.08CM) 2” (5.08CM)

365 - 500 3” (7.75CM) 3” (7.75CM) 3” (7.75CM)

A 24 inch clearance for all serviceable parts is recommended. Clearances may vary

between BTR models – See instruction manual or the label on the heater, for clearances

applicable to your specific model.

CLEARANCES FROM COMBUSTIBLES

BTR TANK TYPE HEATERS

SERVICE HANDBOOK

A.O. Smith Water Products Service Handbook

EXTERIOR CLEARANCE

This illustrates the exterior roof clearances for BTR units with natural draft venting. The

vent shall extend at least 3 feet above the highest point where it passes through a roof of

a building, and at least 2 feet higher than any portion of a building within a horizontal

distance of 10 feet (for vents of 12" in diameter or less). (NFPA 54 ANSI Z 223.1 SEC

7.5.2a). (Sec 7.6.2a may allow reduction to 8 feet with a “ Listed vent cap”).

"Copyright by the American Gas Association. Used by permission of the copyright holder".

BTR TANK TYPE HEATERS

SERVICE HANDBOOK

A.O. Smith Water Products Service Handbook

AIR FOR COMBUSTION

10 CUBIC FEET OF AIR PER 1,000 BTU

Stoichiometric or theoretical complete combustion requires 10 cubic feet of air per 1000

BTUH input of the 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 models.

The National Fuel Gas Code also specifies minimum make-up air opening sizes for

various building installations. (Ref: NFPA 54, ANSI Z223.1, sec 5.3)

2.5 CU.

FT.

EXCESS

AIR

10 CU.

FT.

COMB.

AIR

BTR TANK TYPE HEATERS

SERVICE HANDBOOK

A.O. Smith Water Products Service Handbook

MAKE-UP AIR

DIRECT COMMUNICATION

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

make-up air ducts 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 twelve 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 dilution air and acts as a relief opening for flue gases should the vent become

obstructed or a downdraft condition occur. Additionally, when the heater is installed in a

confined space and communicating with the outdoor air, one permanent opening,

commencing within 12 in. (30 cm) of the top of the enclosure, shall be permitted where

the equipment has clearances of at least 1 in. (2.5 cm) from the sides and back and 6 in.

(16 cm) from the front of the appliance. The opening shall directly communicate with the

outdoors and shall communicate through a vertical or horizontal duct to the outdoors or

spaces (crawl or attic) that freely communicate with the outdoors, and shall have a

minimum free area of:

a. 1 sq. in. per 3000 BTU per hr (7 cm2per kW) of the total input of all equipment

located in the enclosure, and

b. Not less than the sum of the areas of all vent connectors in the confined space.

1 Square

Inch Per

4,000

BTUH

BTR TANK TYPE HEATERS

SERVICE HANDBOOK

A.O. Smith Water Products Service Handbook

MAKE-UP AIR

VERTICAL DUCTS

Often it is more practical to install vertical make-up air ducts to the out doors. Again, two

openings are required - one within 12 inches of the top of the enclosure and one within

twelve 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.

1 Square

Inch Per

4,000

BTUH

BTR TANK TYPE HEATERS

SERVICE HANDBOOK

A.O. Smith Water Products Service Handbook

MAKE-UP AIR

HORIZONTAL DUCTS

When the heater is installed in an interior room with no roof access for vertical ducts,

horizontal make-up air ducts should be installed. When using horizontal ducts, two

openings are required - one within 12 inches of the top of the enclosure and one within

twelve inches 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.

1 Square

Inch Per

2,000

BTUH

Dail

Schedule

BTR TANK TYPE HEATERS

SERVICE HANDBOOK

A.O. Smith Water Products Service Handbook

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 shut down.

BTR TANK TYPE HEATERS

SERVICE HANDBOOK

A.O. Smith Water Products Service Handbook

CONTAMINATED AIR

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,

waxes, salts, etc. are drawn into the combustion chamber with the make-up air and, once

fired, mix with water vapor in the gases to form extremely corrosive hydrochloric or

hydrofluoric acid and other corrosive byproducts.

AIR FOR COMBUSTION

Flammable Items

Flammable items, 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.

BTR TANK TYPE HEATERS

SERVICE HANDBOOK

A.O. Smith Water Products Service Handbook

GAS PRESSURE REQUIREMENTS

Natural Gas Propane Gas

Maximum Supply Pressure 13.8" w.c. 13.8" w.c.

Minimum Supply Pressure 4.5" w.c. 11" w.c.

Manifold Pressure 3.5 " w.c. 10" w.c.

The supply gas pressure is normally measured at the dirt leg or at the gas pressure

tapping on the gas supply shutoff valve. This reading must be measured with 'flowing'

gas.

The manifold gas pressure is measured at the manifold pressure tap of the gas valve

when the gas is flowing.

Supply Gas

Dirt Leg

Manifold

Gas Port

Manifold

Pressure

Tap

BTR TANK TYPE HEATERS

SERVICE HANDBOOK

A.O. Smith Water Products Service Handbook

BTR GAS VALVE

The gas valves used on all BTR water heaters are

24 volt AC combination step opening gas valves.

They incorporate the pilot valve, main valve, and gas

pressure regulators into one body. The inlet view of

the valve features a filter screen and the top knob.

The top knob is a manual on/off gas control for both

the pilot and main gas valves. When the top knob is

placed on the black mark, gas is supplied only to the

pilot valve.

On the top view, we see the pilot solenoid and

pilot and main gas regulators. The top view also

displays the “TH and “TR” terminals. The pilot

gas regulator is found under its cover screw. It is

factory preset at 3.5”w.c. but can be adjusted from

2.5 to 5 inches water column. The main gas

regulator is found under its cover screw. It is

factory preset to 3.5 inches w.c. and adjusts gas

pressure output from 2.5 to 5 inches water

column. The two electrical terminals are marked

TH and TR. The TH terminal is the common

between the pilot valve solenoid coil and the main

valve solenoid coil. The other wire emerging from

the pilot solenoid connects to the pilot valve

electrical output on the IID (terminal PV). The TR

terminal connects directly to the main valve

electrical output from the IID module

(terminal MV).

On the outlet view of the gas valve, we see the

pilot gas connection port, manifold gas connection

port, a limited bleed vent port, the manifold gas and

pressure tap.

See step 18 for BTR-500 gas valve illustration

BTR TANK TYPE HEATERS

SERVICE HANDBOOK

A.O. Smith Water Products Service Handbook

VENTING

Atmospheric Multiple Heaters

All BTR water heaters are classified by ANSI as category I (non-condensing, negative

pressure venting) appliances. They are approved for type B vent.

For larger applications, BTR water heaters can be common vented together either in a

tapered manifold or constant size manifold. (Follow National Fuel Gas Code

requirements for sizing and installation.)

BTRs may be common vented only with other category I appliances. (See venting

section in the National Fuel Gas Code).

A minimum of ¼” rise

per foot of horizontal

vent is re

uired.

Chimne

BTR TANK TYPE HEATERS

SERVICE HANDBOOK

A.O. Smith Water Products Service Handbook

DRAFT INDUCER

Draft inducers can be used with BTR water heaters to mechanically aid a lazy chimney in

vertical vent applications. They are not designed to allow “through-the-wall” vent

installations. (See Power Venter)

SINGLE UNIT INSTALLATION

When mechanically venting, the following items are required:

Qty Description Part No.

1 Draft Inducer (up to 300,000Btuh) 90909

1 Draft Inducer (up to 305,000 thru 500,000 Btuh) 90910

1 Draft Prover Switch 95220

1 Relay Switch 96695

BTR TANK TYPE HEATERS

SERVICE HANDBOOK

A.O. Smith Water Products Service Handbook

POWER VENT KITS FOR SIDEWALL VENTING

Water Heater Models Part Number

BTR-120-200 193933-0

BTR-250-500 193933-1

BTR water heaters can be used

with power vent kits for sidewall

venting. A.O. Smith offers power

vent kits for use on installations with

a maximum of 100 equivalent feet

of vent piping. The power vent kits

also use type B vent materials.

When power venting, specific

exterior clearances must be

maintained, as outlined in the

National Fuel Gas Code. (NFPA

54, ANSI A223.1, sec 7.8)

Male plug

to Cable

Female plug

to Damper

40’, Power Venter

cablewith“Y”

connect

BTR TANK TYPE HEATERS

SERVICE HANDBOOK

A.O. Smith Water Products Service Handbook

BTR SEQUENCE OF OPERATION

1. Thermostat calls for heat 2. Flue dam

er o

ens

3. Intermittent

nition Control

5. Main gas valve opens

7. Thermostat satisfies

4. Pilot gas opens,

Pilot sparks and

flame

roves

6. Main burner i

nites

8. Main and pilot

burners "OFF"

SEQUENCE OF OPERATION

To understand BTR tank type water heaters, an examination of their sequence of

operation is necessary.

When the thermostat calls for heat, the relay in the draft hood assembly activates, de-

energizing the flue damper motor. The damper opens and power flows to the IID

(Intermittent Ignition Device). This activates the IID module to open the pilot valve

and begin sparking at the pilot burner assembly. Once the pilot flame is established

and confirmed back to the IID, the sparking is stopped and the main gas valve is

opened, allowing gas flow to the main burner. When the thermostat satisfie’s, main

and pilot gas is shut off.

9. Flue dam

er closes

BTR TANK TYPE HEATERS

SERVICE HANDBOOK

A.O. Smith Water Products Service Handbook

BTR ELECTRICAL SEQUENCE

100 – 109 Series

BTR TANK TYPE HEATERS

SERVICE HANDBOOK

A.O. Smith Water Products Service Handbook

BTR ELECTRICAL SEQUENCE OF OPERATION

Motor Opens

Damper

Power to Damper

#2 Interrupted

Series 110 and 111

Effikal

Series 110 and 111

Effikal

IID Module

(24V) Receives Voltage

Module (PV) Teminal

Sends 24V to Pilot Coil

Module (Spark) Sends

10,000V Spark to Pilot

Spark Stops

Dam per Motor Energized

and Dam per Closed

Power to Damper

Relay (4) Interupted

Them ostat O pens

Main Burner Heats Tank

Module (MV)

Terminal Sends 24V

To Main Gas Coil

90 Second Trial /

5 Minute Delay Between

Trials - C on tin u ously

Pilot Ignites and Proves Flame

Cam On Damper Blade

Closes Proving End Switch

Damper Spring Opens

Dam per Blade

Motor Relay Interrupts

Power to Motor

Therm ostat Closed

High Limit Closed

Tank Tem perature

Motor Closes

Damper

High Limit (ECO)

Closed

Tank Tem perature

Satisfied

24V Transform er

On / OFF Switch "ON"

120 Vac to Junction Box

BTR TANK TYPE HEATERS

SERVICE HANDBOOK

A.O. Smith Water Products Service Handbook

TROUBLESHOOTING BTR WATER HEATERS

To troubleshoot a BTR water heater check that:

• 120 VAC is supplied to the heater

• the tank is full of water

• gas is supplied to the unit

STEP 1 TEST THE TRANSFORMER

STEP 1 - TO TEST THE TRANSFORMER - Using a multimeter, test for 24 VAC

between the secondary transformer terminals.

IF THEN

The meter does not read 24 VAC: • Check that the 120 VAC is supplied

from the On/Off Switch – if not, replace

switch.

• Check that the 120 VAC is supplied

from transformer.

The meter reads 24 VAC: • Go to step 2.

BTR TANK TYPE HEATERS

SERVICE HANDBOOK

A.O. Smith Water Products Service Handbook

STEP 2 HIGH LIMIT, LEFT TERMINAL TEST

STEP 2. HIGH LIMIT, LEFT TERMINAL TEST. Test for 24 VAC between the left high

limit terminal and ground.

IF THEN

The meter does not read 24 VAC: • Check wiring between transformer and

high limit.

The meter reads 24 VAC: • Go to Step 3.

Note: The high limit (Energy Cut Off) opens if the tank water temperature exceeds 205

degrees. The control is resettable (manually) when the tank water temperature drops

below 185 degrees.

BTR TANK TYPE HEATERS

SERVICE HANDBOOK

A.O. Smith Water Products Service Handbook

STEP 3 TEST HIGH LIMIT RIGHT TERMINAL

STEP 3. TO TEST HIGH LIMIT RIGHT TERMINAL. Ensure that the jumper wire

between the high limit and thermostat is connected, and the damper motor power line is

connected. Test for 24 VAC between the high limit right terminal and ground.

IF THEN

The meter does not read 24 VAC: • Push the reset button and redo the test (storage

water temperature below 185 degrees).

The meter reads 24 VAC: • Go to step 4.

After Push in Reset - 24 VAC is now present

Reasons For Resetting

Condition Cause Solution

High limit open Never set on initial

installation

Push high limit button

Excessive water temperature Faulty thermostat Replace dual control

Heater shut down before

reaching thermostat setting

Faulty high limit Replace dual control

Note: The right terminal of the high limit has a jumper wire connected to the left terminal of the

thermostat. There is also a black wire connecting to the damper motor assembly. This black wire

supplies power to the motor to close the damper during periods of standby.

BTR TANK TYPE HEATERS

SERVICE HANDBOOK

A.O. Smith Water Products Service Handbook

STEP 4 INSPECT THE DAMPER

STEP 4. INSPECT THE DAMPER. Lower the thermostat setting so the unit will not be

calling for heat, then inspect the damper.

IF THEN

If the damper is open: • Go to step 5.

If the damper is closed: • Go to step 7.

Note: If the water temperature in the tank is below 120 degrees F, temporarily disconnect the

jumper wire between the high limit and thermostat to simulate a satisfied thermostat.

STEP 5 CHECK THE PC BOARD

STEP 5. CHECK THE PC BOARD. Test for 24 VAC between the black PC board wire

connection and ground.

IF THEN

24 VAC is not present: • Check the black wire connections

between PC Board and high limit.

24 VAC is present: • Go to step 6.

BTR TANK TYPE HEATERS

SERVICE HANDBOOK

A.O. Smith Water Products Service Handbook

STEP 6 PC BOARD MOTOR TEST

STEP 6. PC BOARD/MOTOR TEST. Check for 24 VAC between the two motor lead

terminals of the PC board. Disconnect the wires for this test.

IF THEN

24 VAC is not present: • Replace the board (AOS part # 6522)

and go to step 7. The board and relay

are one piece. Regardless of which

part is defective, both parts should be

changed.

Voltage is present: • This verifies that the motor is receiving

power but not closing the damper.

• Replace the motor (AOS part # 6521)

and go to step 7.

Note: The service switch may be used to bypass the damper, while waiting for a replacement part.

WARNING - In the event of damper motor failure, verify that the damper is in the "open"

position before utilizing the service switch. (BTR Series 106/107 and some prior series –

changed from momentary push button to service switch).

Service Switch

Motor Lead

Terminals

BTR TANK TYPE HEATERS

SERVICE HANDBOOK

A.O. Smith Water Products Service Handbook

STEP 7 THERMOSTAT TEST

STEP 7. THERMOSTAT TEST. Set the thermostat to call for heat. Using your

multimeter, test for 24 VAC between right terminal and ground.

IF THEN

The meter does not read 24 VAC and the jumper wire

between the high limit and the thermostat is in place:

• Replace the thermostat

The meter reads 24 VAC: • Go to step 8.

Note: If the high limit to thermostat jumper wire was disconnected earlier to simulate a satisfied

thermostat, reconnect the jumper to the terminals.

Note: A yellow wire from this thermostat terminal connects to the damper PC board.

BTR TANK TYPE HEATERS

SERVICE HANDBOOK

A.O. Smith Water Products Service Handbook

GO TO PAGE 27 FOR DAMPER TESTS OF EFFIKAL EQUIPPED (SERIES 110, 111 AND

RETROFIT) MODELS

STEP 8 DAMPER INPUT TEST

STEP 8. DAMPER INPUT TEST. Test for 24 VAC between the yellow wire on the PC

board and ground. Effikal – Check from orange wire to neutral

IF THEN

24 VAC is not present: • Check the black wire connections

between the PC board and high limit.

24 VAC is present • Go to step 6.

STEP 9 TEST THE DAMPER

STEP 9. TEST THE DAMPER. Visually check the damper blade position.

IF THEN

The damper does NOT open fully: • Replace the damper assembly

The damper DOES open fully: • Go to step 10.

Test from

Orange

wire to

Black

(neutral)

BTR TANK TYPE HEATERS

SERVICE HANDBOOK

A.O. Smith Water Products Service Handbook

STEP 10 TEST DAMPER OUTPUT

STEP 10. TEST DAMPER OUTPUT. On a call for heat, the damper relays receives

power through the yellow wire and power to the motor is interrupted. Then, the motor

clutch is disengaged and the damper opens. The damper proves it is open via an end

switch before power flows through the red wire from the PC board.

Place the red test probe on the solder joint of the red wire connection to the damper PC

board.

IF THEN

The meter does not read 24 VAC and the

end switch is closed:

• Replace the PC board

The meter reads 24 VAC • Go to step 11.

Note: The spring rotates the damper blade assembly to the open position. This closes an end

switch.

BTR TANK TYPE HEATERS

SERVICE HANDBOOK

A.O. Smith Water Products Service Handbook

Damper

1234

Black

Red

Yellow

White

Orange Brown Yellow Black

Male Plug

From Heater

Female Plug

EFFIKAL DAMPER

BTR Series 110 and 111 began using the motor open; motor close, Effikal Damper. The

wiring colors from the damper PC Board are different from previous series BTR(C) and

BTC Models.

The heater harness wires still serve the same function:

Service

Switch Adapter

Plug

Heater

Harness

Service

Switch

Motor

Lead

Terminal

Motor

Lead

Motor

Effikal Control Cover (Photo of kit mounting) Effikal Style

Black – 24V Constant if high limit closed

Yellow – 24V To damper if the thermostat is closed

Red – 24V From damper to IID if damper closes end switch

White–Neutral

(

common

)

BTR TANK TYPE HEATERS

SERVICE HANDBOOK

A.O. Smith Water Products Service Handbook

HARNESS CHART

Heater Harness Function Damper Harness

Black 24V Hot 1-Brown

Yellow 24V from Therm 2-Orange

Red 24V from damper 3-Yellow

White 24V common 4-Black

Series 110 and 111 heaters and converted model BTR(C) and BTC heaters with Effikal

Dampers.

NORMAL OPERATION

Condition:

• Heater on standby

• Damper closed

• High Limit closed

STEP A

TEST FOR 24VAC BETWEEN BLACK (COMMON)

AND BROWN

STEP A. TEST FOR 24VAC BETWEEN BLACK (COMMON) AND BROWN

IF THEN

24VAC is present Continue to Step B.

24VAC is not present See Troubleshooting Step A1

Wires are from left to right:

Black iYellow iBrown iWhite

BTR TANK TYPE HEATERS

SERVICE HANDBOOK

A.O. Smith Water Products Service Handbook

NORMAL OPERATION (continued)

Condition:

• Thermostat closed, damper in process of opening

STEP B TEST FOR 24VAC BETWEEN BLACK AND ORANGE

IF THEN

24VAC is present Continue to Step C.

24VAC is not present See Troubleshooting Step A2

Condition:

• Thermostat closed, damper fully open

STEP C TEST FOR 24VAC BETWEEN BLACK AND YELLOW

IF THEN

24VAC is present Continue to Step 11

24VAC is not present See Troubleshooting Step A3

BTR TANK TYPE HEATERS

SERVICE HANDBOOK

A.O. Smith Water Products Service Handbook

TROUBLESHOOTING THE EFFIKAL STYLE DAMPER

Condition:

Thermostat closed, damper

STEP A1

TEST BETWEEN BLACK (COMMON) AND BROWN

ON THE DAMPER BOARD

IF THEN

24VAC is present This is correct

24VAC is not present • SeeSteps1thru4

Check the harness plugs connecting heater

and damper for looseness or damage.

Condition:

Thermostat closed, damper in process of opening.

STEP A2 TEST FOR 24VAC BETWEEN BLACK AND ORANGE

IF THEN

24VAC is present This is correct

24VAC is not present • SeeStep7

• Check the harness plug connecting

heater ----or damaged

Wires are from left to right:

Black iYellow iBrown iWhite

BTR TANK TYPE HEATERS

SERVICE HANDBOOK

A.O. Smith Water Products Service Handbook

TROUBLESHOOTING THE EFFIKAL STYLE DAMPER (continued)

Condition:

Thermostat closed, damper is open fully

STEP A3 TEST FOR 24VAC BETWEEN BLACK AND YELLOW

IF THEN

24VAC is present This is correct – continue to Step 11

24VAC is not present • SeeStep9

• Check the harness plug connecting ----

• Check that cam on shaft rotates with

shaft

• Replace the damper board

BTR TANK TYPE HEATERS

SERVICE HANDBOOK

A.O. Smith Water Products Service Handbook

STEP 11 WIRE HARNESS TEST

STEP 11. WIRE HARNESS TEST. Test for 24 VAC between terminal 24V on the IID

module, and 24V (GND).

IF THEN

24 VAC is not present: • Check the wiring harness.

24 VAC is present: • Go to step 12.

Note: This test may be easier to conduct by removing the red wire from the IID terminal. Test for 24

VAC between the red wire and ground. Reconnect the red wire to the 24V terminal after the test.

BTR TANK TYPE HEATERS

SERVICE HANDBOOK

A.O. Smith Water Products Service Handbook

STEP 12 IID MODULE TEST

STEP 12. IID MODULE TEST (Power to the Pilot Valve). Using a multimeter, test for

24 VAC between terminal PV and 24V (GND) on the IID during the 90 second trial for

ignition.

IF THEN

The meter does not read 24 VAC and the

IID module is not between ignition trials:

• Replace the module.

The meter does read 24 VAC: • Go to step 13

BTR TANK TYPE HEATERS

SERVICE HANDBOOK

A.O. Smith Water Products Service Handbook

STEP 13 PILOT SPARK TEST

STEP 13. PILOT SPARK TEST. Visually check for spark at the pilot assembly.

Note: The pilot burner mounts on the left side of the main burner.

IF THEN

The igniter is not sparking: Check for:

• A 7/64” spark gap

• Spark cable continuity

• Ground cable continuity

Sparking is present: • Go to step 14.

Power To Module May Be Interrupted To Reset .

Trial for Ignition

90 sec. 5 min. 90 sec. 5 min. 90 sec.

Call for

heat

Sparking No

Sparking

Sparking No

Sparking

Continuous

Trial

Sequence

BTR TANK TYPE HEATERS

SERVICE HANDBOOK

A.O. Smith Water Products Service Handbook

STEP 14A PILOT VALVE - OHM TEST

BTR 120 – 400 GAS VALVE

STEP 14A. PILOT VALVE - OHM TEST. If pilot assembly is sparking but no pilot flame

is established, disconnect the pilot valve solenoid leads. Using a multimeter, (set to read

ohms) test for 20* ohms resistance +/- 5 through the solenoid coil.

IF THEN

The meter dose not read 20 ohms plus or

minus 5:

• Replace gas valve

The meter does read 20 ohms plus or

minus 5:

• Gas valve should work. Also check that

pilot gas is present and pilot tube or

orifice are not blocked

BTR TANK TYPE HEATERS

SERVICE HANDBOOK

A.O. Smith Water Products Service Handbook

STEP 14B PILOT VALVE TEST – BTR 500 ONLY

STEP 14B. PILOT VALVE TEST – BTR 500 ONLY. Testing the two coils of the

Honeywell VR8404P 5004 gas valve used on the model BTR 500 only. Because of built

in diodes, it is difficult to test for ohms resistance through these coils. The following is a

DC amperage check of the main and pilot coils.

Condition:

• Tank calls for heat

• PV terminal of module has 24 Vac

• No Pilot flame

Test Procedure:

• Turn off power to heater

• Meter set to test for DC amperage (on AOS meters, the black wire is in the

“com” port, the red wire is in the “10A” port, the dial is set to 20M/10A in the DC

AMP test area).

• Blue “PV” wire is disconnected from the ignition PV terminal.

• Install meter in series between gas valve and ignition module – 10A wire to

blue gas valve lead, common wire to PV module terminal.

• Turn power on to heater, after module receives 24V

Test DC Amperage through Pilot coil of gas valve

IF THEN

.75 to .85 DCA is not present: • Replace the gas valve

.75 to .85 DCA is present • Pilot should work if gas (not air) is present to pilot

Power off, reattach blue gas valve wire to PV terminal of module.

RED

WHITE

BLUE

MANIFOLD

PRESSURE

TAP

MANIFOLD

PRESSURE

TAP

PILOT GAS

MANIFOLD

GAS

The MV/PV wire on the IID is connected to the white wire

The MV wire on the IID is connected to the red wire.

BTR TANK TYPE HEATERS

SERVICE HANDBOOK

A.O. Smith Water Products Service Handbook

STEP 15 MAIN BURNER TEST

Note: BTR series 108 and 109 implemented a new main burner stamping process –

burners appear the same as illustrated.

STEP 15. MAIN BURNER TEST. Visually check for main burner.

IF THEN

The main burner ignites: • Sequence is complete

The main burner does not ignite • Go to step 16

BTR TANK TYPE HEATERS

SERVICE HANDBOOK

A.O. Smith Water Products Service Handbook

STEP 16 FLAME RECTIFICATION

STEP 16. FLAME RECTIFICATION

Note: Flame rectification means that an alternating current (AC) signal is changed to a direct current (DC)

signal. The pilot flame is the 'switch' which connects the pilot hood to the igniter and ground. If the pilot

hood and igniter sensor had the same surface area, the flame 'switch' would conduct an AC signal.

Because the pilot surface is greater than the igniter surface, the signal becomes a DC current that the

module can interpret. The pilot hood must be properly grounded and the pilot flame must remain in

contact with both surfaces for the flame proving signal to remain constant.

If the signal is broken for just 8 tenths of a second, the heater will cycle off.

Sparking at the pilot will continue if an insufficient signal is received by the module.

Sparking at the pilot will stop almost immediately after the ignition module senses the pilot flame.

IF THEN

Sparking continues after pilot is

established:

• Check wire connections

• Check flame contact between hood

and lighter

• Clean pilot burner surfaces

• Replace pilot assembly

Sparking stops: • Go to step 17.

BTR TANK TYPE HEATERS

SERVICE HANDBOOK

A.O. Smith Water Products Service Handbook

STEP 17 IID MODULE TEST

Pilot is lit - Sparking has stopped.

STEP 17. IID MODULE TEST (Power to the Main Valve). Using a multimeter, test for

24 VAC between terminal MV on the IID and 24V (GND).

IF THEN

24 VAC is not present: • Replace the IID module. Conduct Step

18 before applying power to

replacement module.

24 VAC is present: • Go to step 18.

BTR TANK TYPE HEATERS

SERVICE HANDBOOK

A.O. Smith Water Products Service Handbook

STEP 18A MAIN GAS VALVE CHECK

BTR 120 – 400 GAS VALVE

STEP 18A. MAIN GAS VALVE CHECK. Disconnect wires from gas valve TH and TR

terminals. Using a multimeter, test for 68 ohms plus or minus 5 between TH and TR on

themainvalvecoil.

IF THEN

The meter reads ‘O’ or infinity • Replace the gas valve

The meter reads 68* ohms plus or minus 5 • The main burner will ignite

BTR TANK TYPE HEATERS

SERVICE HANDBOOK

A.O. Smith Water Products Service Handbook

STEP 18B MAIN GAS VALVE COIL CHECK

STEP 18B. MAIN GAS VALVE COIL CHECK – BTR 500 ONLY

Condition:

• Pilot lights

• Sparking stops

• No main burner ignition

Test Procedure:

• Power off

• Disconnect red, main valve wire from module MV terminal

• Meter set to test for DC amperage

• 10A wire to red gas valve wire, COM wire to MV terminal of ignition module

• Turn power on to heater

• After pilot lights and sparking stops

IF: THEN:

.25 to .35 DC Amps is not present • Replace the gas valve

.25 to .35DCA is present • Main burner gas should ignite.

Be certain to correct you meter wire connections and setting before performing further

tests.

RED

WHITE

BLUE

MANIFOLD

PRESSURE

TAP

MANIFOLD

PRESSURE

TAP

PILOT GAS

MANIFOLD

GAS

The PV wire is connected to the blue wire

The MV/PV wire on the IID is connected to the white wire.

The MV wire is disconnected from the gas valve.

BTR TANK TYPE HEATERS

SERVICE HANDBOOK

A.O. Smith Water Products Service Handbook

BTR WIRING DIAGRAM - NATURAL AND PROPANE GAS

Honeywell Ignition System (110 – 109 Series)

IF ANY OF THE ORIGINAL WIRE AS SUPPLIED MUST BE

REPLACED, USE ONLY TYPE 105° C THERMOPLASTIC OR

EQUIVALENT.

BLUE

WHITE

RED

MV/

GAS VALVE FOR

BTR-500/A ONLY

BTRTANKTYPEHEATERS

SERVICE WORKBOOK

A.O. Smith Water Products Service Handbook

GENERAL SERVICE CHART

CONDITION CAUSE SOLUTION

DAMPER OPENS NO POWER

TO IID MODULE . DAMPER NOT FULLY OPEN

. DEFECTIVE PROTECTOR

SWITCH

.EFFIKAL – REPLACE DAMPER CONTROL

ASSEMBLY

. REPLACE DAMPER

. REPLACE PC BOARD

PILOT LIGHTS, SPARKS

CONTINUOUSLY PILOT FLAME NOT PROVING SEE FLAME RECTIFICATION - STEP 16

HEATER WILL NOT IGNITE NOT PROVING PILOT

FLAME EXISTANCE

INTERRUPT 120 VAC POWER

. CHECK GROUND WIRE

ATTACHMENT

. CLEAN OR REPLACE PILOT

ASSEMBLY

PILOT GAS NOT COMPLETELY

INTERRUPTED AT END OF

HEATING CYCLE

. CHECK SUPPLY GAS PRESSURE

. REPLACE GAS VALVE

. THERMAL EXPANSION ADD THERMAL EXPANSION TANK

WEEPING TEMPERATURE

AND

PRESSURE RELIEF VALVE

. FAULTY VALVE REPLACE RELIEF VALVE

. EXCESSIVE WATER

TEMPERATURE

. CHECK WIRING

. REPLACE DUAL CONTROLLER

LARGE VOLUME WATER

RELIEF FROM T&P VALVE

. FAULTY RELIEF VALVE REPLACE RELIEF VALVE

PREMATURE TANK

LEAKAGE

CONDENSATION . INCREASE STORED WATER

TEMPERATURE AND CONFIRM

PROPERLY SIZED APPLICATION

CONTAMINATED AIR . REMOVE CONTAMINANTS.

. SUPPLY CLEAN COMBUSTION

AIR.

WATER HAMMER . ADD WATER HAMMER

ARRESTOR.

. REDUCE WATER PRESSURE.

. REMOVE UNNECESSARY CHECK

VALVES.

THERMAL EXPANSION ADD THERMAL EXPANSION TANK.

DEPLETED ANODES SCHEDULE ANODE CHECKS -

REPLACE AS NEEDED.

DAMPER WILL NOT OPEN BINDING SHAFT SUPPORT VENTING

SHAFT SPRING WEAK/BROKEN REPLACE DAMPER NON-EFFIKALS

DAMPER MOTOR REPLACE MOTOR EFFIKAL-REPLACE DAMPER

CONTROL ASSEMBLY

NO SPARK AT PILOT -

DAMPER FULLY OPEN

DAMPER ASSEMBLY REPLACE PC BOARD - SEE STEP 10

Services Switch may bypass problem until

replacement part is received. (EFFIKAL –

REPLACE DAMPER CONTROL ASSEMBLY

IID MODULE REPLACE IID STEP 12

SPARK CABLE REPLACE CABLE STEP 13

BTRTANKTYPEHEATERS

SERVICE WORKBOOK

A.O. Smith Water Products Service Handbook

GENERAL QUESTIONS AND ANSWERS

Q. What changes caused series 106/107 and 108/109 to be implemented?

A. The 106 and 107 series units changed from the momentary push button to a slide

switch. The 108 and 109 series implemented a new main burner construction process. The

damper boards with service switch and new style main burners will automatically be

replacement parts for previous series heaters if parts are ordered.

Q. What is unique about the Canadian – BTRC – models vs. U.S. BTR models?

A. The Canadian models have different dimensions to meet Canadian code requirements.

Q: How much electrical power is required for a BTR water heater?

A: The BTR models draw approximately .7 Amps at 120VAC.

Q: The units require "leg kits" to meet National Sanitation Foundation standards. What are the

part numbers for these kits?

A: The BTR model heaters need AOS kit numbers:

BTR 120-400 (except BTR 197&198 series 100) = Part # 6570-0

BTR 197&198 Series 100 = Part # 6570-5

BTR 500 = Part # 6570-7

Q: When should BTRs be delimed?

Many variables affect the liming up process including:

water temperature - The amount of lime accumulation during the same period of time will be

nearly 2 times greater if water is stored at 140 degrees F than at 120 degrees F. A 180

degree setting will build up lime about seven times as fast as a 140 degree F setting.

volume of water - The more gallons flowing through the BTR, the more rapid the

accumulation.

hardness – The harder the water the faster lime build up occurs. 1 to 3.5 grains per gallon is

"soft", 3.5 to 7 grains per gallon is "moderate", 7 to 10.5 grains per gallon 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

burners are on.

Q: What effect will lime build-up have on the BTR water heater?

A: One eighth inch of scale build-up may reduce efficiency as much as 22%; a 1/4 inch build-up,

as much as 38%.

A: Less efficient heat transfer means more bottom head expansion/contraction stress and

premature leakage.

A: Heavy build-up on the bottom head and bottom portion of the flue pipes leads to more heat

transfer at the top of the flues. This can lead to stacking or erratic thermostat operation.

Q: Anode rods provide additional protection against corrosion. When should these be

replaced?

A: When large gouges or pits appear in the anodes, replace them. It is recommended that

these be inspected every 6 months.

BTRTANKTYPEHEATERS

SERVICE WORKBOOK

A.O. Smith Water Products Service Handbook

BTR MODELS 197 AND 198

Series 100-101

BTRTANKTYPEHEATERS

SERVICE WORKBOOK

A.O. Smith Water Products Service Handbook

BTR MODELS 197 AND 198 (continued)

Series 100-101

BTRTANKTYPEHEATERS

SERVICE WORKBOOK

A.O. Smith Water Products Service Handbook

PARTS LIST for BTR Models 197 and 198 Series 100 & 101

Item Parts Description BTR 197 BTR 198

1 Bracket For Main Burner Orifice............... 098044(5) 098044(5)

2 Main Burner ............................................. 192322 192322

3 Main Burner w/Pilot Bracket..................... 193873-0 193873-0

4 Pilot Burner Natural ................................. 193314-0 193314-0

5 Pilot Burner Propane ............................... 193314-1 193314-1

6 Gasket ..................................................... 99036 99036

7 Pressure Plate ......................................... 99037 99037

8 Screws, Self Tapping............................... 69852 69852

9 Control, Ignition Module ........................... 193325 193325

10 Control, Dual w/ECO ............................... 192828 192828

11 Drafthood................................................. 192957-4 192957-4

12 Manifold................................................... 76244-2 76244-2

13 Instruction Manual ................................... 193927 193927

14 Main Burner Orifice Natural .....................76243-32 76243-32

15 Main Burner Orifice Propane.................... 76243-49 76243-49

16 Anode Rod............................................... 43817-38 (4) 43817-42 (4)

17 T & P Relief Valve ................................... 99465-7 99465-7

18 Transformer ............................................. 193444 193444

19 Inlet Tube ................................................ 192626 192626

20 Gas Valve Natural.................................... 192827-2 192827-2

21 Gas Valve Propane.................................. 192827-3 192827-3

22 Off/On Switch .......................................... 193243 193243

BTRTANKTYPEHEATERS

SERVICE WORKBOOK

A.O. Smith Water Products Service Handbook

BTR MODELS 120 through 500

Series 104-105

BTRTANKTYPEHEATERS

SERVICE WORKBOOK

A.O. Smith Water Products Service Handbook

BTR MODELS 120 through 500 (continued)

Series 104-111

BTRTANKTYPEHEATERS

SERVICE WORKBOOK

A.O. Smith Water Products Service Handbook

PARTS LIST FOR BTR Models 120 Through 500(A)

Series 104 Through 109 Series

(Series 106/107 have a service switch on Circuit Board 6522; Series 108/109 have new

main burner production method. Both parts will automatically be shipped

on 104 thru 109 series heaters.)

Item Parts Description BTR-120 BTR-154 BTR-180 BTR-199 BTR-200 BTR-250

1 Main Burner, Orifice Bracket 98044(3) 98044(3) 98044(5) 98044(5) 98044(5) 98044(5)

2 Main Burner 192322 98047 192322 192322 192322 098047

3 Main Burner w/Pilot Bracket 193873-0 193873-1 193873-0 193873-0 193873-0 193873-0

4 Pilot Burner, Natural 193314-0 193314-0 193314-0 193314-0 R 193314-4

5 Pilot Burner, Propane 193314-1 193314-1 193314-1 193314-1 193314-1 193314-3

6 Gasket, Cleanout 99036 99036 99036 99036 99036 99036

7 Pressure Plate, Cleanout 99037 99037 99037 99037 99037 99037

8 Screw, Self tapping, Cleanout 69852 69852 69852 69852 69852 69852

9 Control, Ignition Module 193325 193325 193325 193325 193325 193325

10 Control, Dual w/eco 192828 192828 192828 192828 192828 192828

11 Drafthood 193597-0 193597-1 192957-0 192957-0 192957-0 193287

11 Drafthood 110, 111 Series

12 Manifold 76244-0 76244-0 76244-2 76244-2 76244-2 76244-2

13 Instruction Manual, (not illustrated) 193927 193927 193927 193927 193927 193927

14 Main Burner Orifice, Natural 76243-32 76243-30 76243-35 76243-32 76243-32 76243-xx

15 Main Burner, Orifice, Propane 76243-49 76243-46 76243-51 76243-49 76243-48 76243-xx

16 Anode Rod 43817-38 (2) 43817-38 (2) 43817-38 (4) 43817-38 (4) 180618-42 (3) 180618-42 (4)

17 T & P Relief Valve 99465-7 99465-7 99465-7 99465-7 99465-7 192467

18 Transformer 193444 193444 193444 193444 193444 193444

19 Inlet Tube 193729 192626 193729 193729 192626 192626

20 Gas Valve, Natural 192827-2 192827-2 192827-2 192827-2 192827-2 192827-2

21 Gas Valve, LP 192827-3 192827-3 192827-3 192827-3 192827-3 192827-3

22 Off/On Switch 193243 193243 193243 193243 193243 193243

Item Parts Description BTR-251 BTR-275 BTR-305 BTR-365 BTR-400 BTR-500

1 Main Burner, Orifice Bracket 98044(7) 98044(5) 98044(7) 98044(9) 98044(9) 98044(9)

2 Main Burner 98047 98047 192322 192322 192322 192322

3 Main Burner w/Pilot Bracket 193873-0 193873-1 193873-0 193873-0 193873-0 193873-0

4 Pilot Burner, Natural 193314-4 193314-4 193314-4 193314-4 193314-4 193314-4

5 Pilot Burner, Propane 193314-3 193314-3 193314-3 193314-3 193314-3 193314-3

6 Gasket, Cleanout 99036 99036 99036 99036 99036 99036

7 Pressure Plate, Cleanout 99037 99037 99037 99037 99037 99037

8 Screw, Self tapping, Cleanout 69852 69852 69852 69852 69852 69852

9 Control, Ignition Module 193325 193325 193325 193325 193325 193325

10 Control, Dual w/eco 192828 192828 192828 192828 192828 192828

11 Drafthood 193287 193287 193287 193287 193287 193287

11 Drafthood 110, 111 Series

12 Manifold 76244-3 76244-2 76244-3 76244-4 76244-4 76244-4

13 Instruction Manual, (not illustrated) 193927 193927 193927 193927 193927 193927

14 Main Burner Orifice, Natural 76243-xx 76243-xx 76243-37 76243-32 76243-31 76243-28

15 Main Burner, Orifice, Propane 76243-xx 76243-xx 76243-48 76243-49 76243-48 76243-44

16 Anode Rod 43817-38 (4) 180618-42 (3) 43817-38 (4) 180618-42(4) 180618-42 (3) 180618-42 (4)

17 T & P Relief Valve 192467 192467 192467 192467 192467 192467

18 Transformer 193444 193444 193444 193444 193444 193444

19 Inlet Tube NA 192626 NA 192626 192626 192626

20 Gas Valve, Natural 192827-2 192827-2 192827-2 192827-2 192827-2 193366-0

21 Gas Valve, LP 192827-3 192827-3 192827-3 192827-3 192827-3 193366-1

22 Off/On Switch 193243 193243 193243 193243 193243 193243

∗For complete parts list call 1-800-433-2545

BTRTANKTYPEHEATERS

SERVICE WORKBOOK

A.O. Smith Water Products Service Handbook

COMPONENT PART INFORMATION

NAME SPECIFICATIONS AOS PART NUMBERS

DUAL

CONTROLLER THERMOSTAT

120-180ORANGE, + 4O,5

DIFFERENTIAL,

LIQUID FILLED, ANTI-

STACKING

AOS # 192828

HIGH LIMIT

(ECO)

OPENS - 205OFIXED,

MANUAL

RESET BELOW 185O

GAS VALVE NATURAL GAS BTR 120-400;24VAC, 60hz,

.6A,.7” to 3.5” W.C.,

STEP OPEN

BTR 500; 24VAC, 60hz,

Dual Gas Valve,

STEP OPEN

AOS # 192827-2

AOS # 193366-0

PROPANE

GAS

BTR 120-400;

2.5 – 10” W.C.

STEP OPEN

BTR 500; 24VAC, 60hz,

Dual Gas Valve,

STEP OPEN

AOS # 192827-3

AOS # 193366-1

INTERMITENT

IGNITION

DEVICE

CONTROL

NATURAL GAS

AND

PROPANE

GAS

24 VAC, 50-60 HZ, .1A;

.7 MICROAMP SIGNAL

CONTINUOUS RETRIAL

AOS 193325

DAMPER COMPLETE

ASSEMBLY

SEE PARTS LIST

MOTOR 24 VAC, 60 HZ, 120 RPM,

5WATT

AOS #6521

P.C. BOARD

W/RELAY

Service Switch AOS #6522

TRANSFORMER 120 V PRIMARY, 24 VAC

SECONDARY,

40 VA, 50-60 HZ, CLASS 2

"B"

AOS #193444

BTRTANKTYPEHEATERS

SERVICE WORKBOOK

A.O. Smith Water Products Service Handbook

BTR SERVICE CHECKLIST

(This service checklist may be photo copied to assist with BTR service call.)

This checklist is intended to aid the Service Agent in determining that the A.O. Smith

BTR Water Heater has been properly installed and is operating correctly. Because the

circumstances of each installation may vary greatly, it is not intended to be an all-

inclusive list of the problems 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 INSTALLATION DATE

MODEL NUMBER SERVICE DATE

SERIAL NUMBER LOCATION ADDRESS

GAS TYPE - CHECK ONE

NATURAL PHONE( ) ___ - ____

PROPANE

I. Check Clearances (circle answer)

A. Are exterior clearances adequate? yes no

B. Are interior clearances adequate? yes no

Comments:

II. Check Makeup Air Requirements

A. Is the quantity of make-up air adequate per the National Fuel Gas Code? yes no

Comments:

B. Is the quality of make-up air adequate? yes no

Comments:

III. Gas Pressure (fill in blank)

A. Supply gas pressure inches of w.c.

B. Manifold gas pressure (main burner) inches of w.c.

Comments:

IV. Venting (check)

A. Properly sized per the National Fuel Gas Code? yes no

B. Does the installation have mechanically assisted venting? yes no

If so, is it operational? yes no

Comments:

V. WATER PIPING

BTRTANKTYPEHEATERS

SERVICE WORKBOOK

A.O. Smith Water Products Service Handbook

Is the system properly sized? yes no

Is the system properly installed? yes no

Are there any water leaks? yes no

Does the installation have a recirculating system? yes no

If so, is it operational? yes no

VI. PROPER SEQUENCE OF OPERATION

During standby does damper close on standby? yes no

During standby is pilot flame off? yes no

On a call for heat does thermostat close? yes no

On a call for heat does damper open completely? yes no

Does sparking begin at pilot? yes no

Is pilot flame established? yes no

If so, does sparking stop? yes no

Does main burner ignite? yes no

Does the thermostat satisfy? yes no

Does damper close? yes no

Comments:

VII. SAFETY

A. Gas

Does pilot flame prove before main burner ignites? yes no

Does damper blade fully open before ignition sequence occurs? yes no

Is burner cover plate in place? yes no

Is burner floor shield in place? yes no

Does IID lockout occur after 30 sec. trial for ignition? (Propane models only) yes no

B. Water Temperature

Is the thermostat adjusted to the lowest acceptable temperature? yes no

Does the installation have a mixing valve? yes no

If so, is it operational? yes no

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? yes no

C. Electrical

Is the 120 VAC electrical power supply properly wired? yes no

Are all the BTR control covers in place? yes no

Is the 120 VAC electrical power supply properly fused? yes no

D. Flammables

Are flammable materials located in the area of the water heater? yes no

Are flammable vapors located in the area of the water heater? yes no

Comments:

(This service checklist may be photo copied to assist with BTR service call.)

BTRTANKTYPEHEATERS

SERVICE WORKBOOK

A.O. Smith Water Products Service Handbook

COMMENTS

Author: Terry Mulder

A O Smith 120 Trough 500 Handbook NAME

120trough500 0c48242d-3c83-4152-90f5-c2442a241ec6 A.O. Smith Water Heater 120 trough 500 User Guide |

Navigation menu

Versions of this User Manual:

Views

Navigation