Bradford White M1TW50S, M4TW50T, M1TW60T, M4TW40T, M4TW60T Service Manual

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Manual 238-46238A-00A

SERVICE

MANUAL

Troubleshooting Guide

and Instructions for Service

(To be performed ONLY by

qualified service providers)

Models Covered

by This Manual:

M1TW40S*F (BN,CX,SX)
M1TW50S*F (BN,CX,SX)
M1TW60T*F (BN,CX,SX)

M4TW40T*F (BN,SX)
M4TW50T*F (BN,SX)
M4TW60T*F (BN,SX)

M2TW50T*F (BN,CX,SX)
M2TW65T*F (BN,CX,SX)

TW450S65F (B,C,S)*(N,X)
TW465S65F (B,C,S)*(N,X)
(*) Denotes Warranty Years

Through-The-Wall Gas Water Heaters

TTW Series

®

The Bradford White

2

Through-The-Wall Gas Water Heaters

Page TTW Service Procedure

Introduction 4 - - -

How to use this manual 5 - - -

Tool required for service 5 - - -

Specifications 6 - - -

Control Timings 9 - - -

Sequence of Operation 10 - - -

Troubleshooting 13 - - -

Burner Inspection, Cleaning and Replacement 15 I

Pilot Testing, Cleaning and Replacement 17 II

Pressure Switch Testing and Replacement 18 III

Blower Testing and Replacement 20 IV

Blower Temperature Switch Testing and Replacement 22 V

Gas Control & Thermal well Testing & Replacement 24 VI

Flammable Vapor Sensor Testing and Replacement 28 VII

Safety Circuit Voltage Trace 29 VIII

115VAC Circuit Trace 30 IX

Dip Tube inspection and Replacement 31 X

Anode Inspection and Replacement 32 XI

Flue Baffle Inspection and Replacement 33 XII

Inner Door Removal, Inspection & Replacement

®

ScreenLok

Flame Arrestor Cleaning

Glossary of Terms

Parts List

34 XIII

37 XIV

38 - - -

39 - - -

Page 2

Page 2

WARNING: If the information in these instructions

3

is not followed exactly, a fire or explosion may
result causing property damage, personal injury, or
death.

Incorrect operation of this appliance

CAUTION

may create a hazard to life and

property and will nullify the warranty.

FOR YOUR SAFETY

Do not store or use gasoline or other flammable,
combustible, or corrosive vapors and liquids in the
vicinity of this or any other appliance.

WHAT TO DO IF YOU SMELL GAS

Do not try to light any appliance.
Do not touch any electrical switch; do not use any
phone in your building.
Immediately call your gas supplier from a neighbor's

phone. Follow the gas supplier's instructions.
If you cannot reach your gas supplier, call the fire

department.

Installation and service must be performed by a qualified
installer, service agency or the gas supplier.

WARNING

Water heaters are heat producing appliances. To

avoid damage or injury, do not store materials

against the water heater or vent-air intake system.

Use proper care to avoid unnecessary contact

(especially by children) with the water heater and

vent-air intake components. UNDER NO

CIRCUMSTANCES MUST FLAMMABLE

MATERIALS, SUCH AS GASOLINE OR PAINT

THINNER BE USED OR STORED IN THE VICINITY

OF THIS WATER HEATER, VENT-AIR INTAKE

SYSTEM OR IN ANY LOCATION FROM WHICH

FUMES COULD REACH THE WATER HEATER OR

VENT-AIR INTAKE SYSTEM.

CAUTION

If sweat fittings are to be used DO NOT apply heat to

the nipples on top of the water heater. Sweat the

tubing to the adapter before fitting the adapter to the

water connections. It is imperative that heat is not

applied to the nipples containing a plastic liner.

WARNING

Hydrogen gas can be produced in an operating

water heater that has not had water drawn from the

tank for a long period of time (generally two weeks or

more). Hydrogen gas is extremely flammable.

prevent the possibility of injury under these

conditions, we recommend the hot water faucet to be

open for several minutes at the kitchen sink before

you use any electrical appliance which is connected

to the hot water system. If hydrogen is present,

there will be an unusual sound such as air escaping

through the pipes as hot water begins to flow. Do

not smoke or have open flame near the faucet at the

time it is open.

To

Do not store or use gasoline or other

DANGER

flammable, combustible, or corrosive

vapors and liquids in the vicinity of this

or any other appliance.

IMPORTANT

Before proceeding, please inspect the

water heater and its components for

possible damage. DO NOT install any

water heater with damaged

components. If damage is evident
then please contact the supplier where
the water heater was purchased or the

manufacturer listed on the rating plate

for replacement parts.

WARNING

DO NOT ATTEMPT TO LIGHT ANY GAS APPLIANCE
IF YOU ARE NOT CERTAIN OF THE FOLLOWING:

Liquefied petroleum gases/propane gas and natural
gas have an odorant added by the gas supplier that

aids in the detection of the gas.
Most people recognize this odor as a “sulfur” or
“rotten egg” smell.
Other conditions, such as “odorant fade” can cause
the odorant to diminish in intensity, or ”fade”, and not
be as readily detectable.
If you have a diminished sense of smell, or are in
any way unsure of the presence of gas, immediately
contact your gas supplier from a neighbor's

telephone.
Gas detectors are available. Contact your gas supplier,
or plumbing professional, for more information.

WARNING

FAILURE TO INSTALL AND MAINTAIN A NEW, LISTED

3/4” X 3/4” TEMPERATURE AND PRESSURE RELIEF

VALVE WILL RELEASE THE MANUFACTURER FROM

ANY CLAIM THAT MIGHT RESULT FROM EXCESSIVE

TEMPERATURE AND PRESSURES.

CAUTION

Turn off or disconnect the electrical power supply to the
water heater before servicing. Label all wires prior to
disconnection when servicing controls. Wiring errors
can cause improper and dangerous operation. Verify
proper operation after servicing.

Page 3

Page 3

4

Introduction

4

The new Bradford White TTW1, TTW2 & TW4 water heaters are designed to provide reliable
performance with enhanced standard features. New design features include reliable spark to
pilot ignition system, enhanced diagnostics, simplified servicing, significantly quiet operation
and additional vent lengths.

Spark to Pilot Ignition System - employing the spark to pilot ignition system promotes
reliable and consistent pilot and main burner ignitions to provide hot water on demand.

Integrated Immersion Thermostat/Gas Control Valve with LED - was developed for ease
of troubleshooting by providing simple diagnostic codes to pinpoint an installation or
component performance issue.

New Powerful Blower - will eliminate problems with difficult venting situations.

Quieter and Cooler Blower Operation - blower noise is significantly reduced for both

interior and exterior environments. Cooler operation increases blower life by reducing bearing
wear and noise.

Rugged Wiring Connections - receptacle type connections promote error free wiring.

Increased Vent Lengths - increased venting performance is achieved while maintaining

Energy Factor & FHSR performance.

The TTW1 (M1TW), TTW2 (M2TW) & TW4 water heaters use a combustion system were
flue gases are combined with dilution air to reduce the flue gas temperature in the blower. The
diluted flue gases are evacuated to the exterior through low temperature vent materials. The
gas control maintains water temperature, ignition sequence and regulates gas flow. A safety
circuit consisting of a pressure switch and blower temperature switch verifies proper conditions
exist for safe and reliable operation. If a situation outside of normal operating parameters
exists, the gas control diagnostic LED will flash a code to positively identify an operational
issue.

This service manual is designed to facilitate problem diagnosis and enhance service efficiency.
To further promote quicker service times the new gas valve can be removed and replaced
without draining the water heater. A special tool is required and will be provided with each gas
valve kit shipped from our Service Parts department.

Please read the service manual completely before attempting service on this new series of
power vent models.

Page

How to Use This Manual

5

It is intended for this manual to be used by qualified service personal for the primary purpose of
troubleshooting and repair of the Bradford White TTW Series water heaters. Understanding the
sequence of operation section of this manual will contribute greatly to troubleshooting the water
heater.

The Honeywell WV4460E Electronic Gas Control will display error codes in the event of abnormal
operation. Error codes are listed in the troubleshooting chart beginning on page 13 of this service
manual. The troubleshooting chart will also indicate the probable cause for the error code and
direct the service professional to a service procedure to properly diagnose the abnormal operation.

In some difficult to diagnose conditions, it may be necessary to isolate the heater from the vent
system to determine the problem.

Contact the Bradford White technical support group immediately if diagnosis can not be made
using the methods described in this service manual.

Manometer: A liquid “U” tube type or a digital (magna-helic) type can be used. This

device is used to measure gas and/or air pressure and vacuum.

Multi-Meter: A digital type is strongly recommended. This device is used to measure

electrical values. The meter you select must have the capability to
measure volts AC, volts DC, Amps, micro-amps and ohms.

Electronic Probes: In some cases, standard multi-meter probes will damage or simply

not be effective to obtain certain voltage and ohm reading. It will be
necessary to have special electronic “pin” type multi-meter probes.
These probes are available at most electronic wholesale outlets.

Thermometer: Used to measure water temperature. An accurate thermometer is

recommended.

Water Pressure Gage: Used to measure water supply pressure. Also used to determine tank

pressure by adapting to the drain valve of the heater.

Gas Control Service Tool: BWC part number 239-45991-00. A specialized tool designed to remove

the gas control from gas control thermal well. Available from
your Bradford White parts supplier.

Various Hand Tools: Pipe wrench, channel locks, open end wrenchs (3/8",7/16",½"),

12" crescent wrench, Allen wrench set, screw drivers (common &
Phillips), ¼" nut driver, pliers (common & needle nose), socket set, side
cutters wire cutters, wire strippers, wire crimpers, torpedo level, small
shop vac, step ladder, and flashlight, 5 gallon pail.

Page 5

Page 5

Specifications

6

Power supply Dedicated 115VAC, 60 Hz, 15A

Gas Supply Pipe Minimum 1/2" NPT (schedule 40 black iron pipe recommended)

Approved Gas Type Natural or Propane. Unit must match gas type supplied.

Gas Pressure 5.0" W.C. min. for Nat gas, 11.0" W.C. min. for L.P. gas, 14.0" W.C. maximum (Nat. & L.P.)

Venting System Power vent through the wall or vertical through the roof

Approved Vent Materials PVC, CPVC or ABS

Minimum Clearance
for Servicing

Water Supply Pressure 150 PSI maximum allowable working pressure. Check local codes for supply pressure

Thermal well TCO Limit Residential 188°F (87°C), Commercial 199°F (93°C)

Residential Temperature
Set Point Range

Commercial Temperature
Set Point Range

Blower Temperature
Switch

18" from top, 24" from front, 4" sides and rear.

60°F (16°C) to 160°F (71°C) (Approximate temperatures)

80°F (27°C) to 180°F (82°C) (Approximate temperatures)

Normally closed, opens @ 165°F (74°C), auto reset @ 130°F (54°C).

Pressure switch

Blower

TTW1 (M1TW) Models:
Normally open, closes on vacuum increase @ -.68, opens on vacuum decrease @ -.65

TTW1 (M4TW) Models:
Normally open, closes on vacuum increase @ -.83, opens on vacuum decrease @ -.80

TTW2 (M2TW & TW4) Models:
Normally open, closes on vacuum increase @ -1.28, opens on vacuum decrease @ -1.25

TTW1 (M1TW & M4TW) Models:
115VAC, 60Hz, 3.1 amps, 3000 RPM, 42CFM@1.5" W.C.

TTW2 (M2TW & TW4) Models:
115VAC, 60Hz, 3.1 amps, 3000 RPM, 68CFM@0.4" W.C.

Page 6

Venting Specifications for:

7

40 Gallon
50 Gallon

60 Gallon

Specifications

Vent Tables

2" Diameter (5.1 cm) PVC Vent Connector Lengths

Terminating

Through the Wall

# of

Elbows

1 45 (13.7) 2 (.6)

Maximum Straight

Length ft (m)

Minimum Straight

Length ft (m)

Through the Wall 2 40 (12.2) 2 (.6)

Through the Wall 3 35 (10.7) 2 (.6)

Through the Wall 4 30 (9.2) 2 (.6)

Through the Roof 0 50 (15.2) 7 (2.1)

Through the Roof 1 45 (13.7) 7 (2.1)

Through the Roof 2 40 (12.2) 7 (2.1)

Through the Roof 3 35 (10.7) 7 (2.1)

Through the Roof 4 30 (9.2) 7 (2.1)

3" Diameter (7.6 cm) PVC Vent Connector Lengths

Terminating

Through the Wall

# of

Elbows

1 115 (35.0) 10 (3.1)

Maximum Straight

Length ft (m)

Minimum Straight

Length ft (m)

Through the Wall 2 110 (33.5) 10 (3.1)

Through the Wall 3 105 (32.0) 10 (3.1)

Through the Wall 4 100 (30.5) 10 (3.1)

Through the Wall 5 95 (29.0) 10 (3.1)

Through the Roof 0 120 (36.6) 15 (4.6)

Through the Roof 1 115 (35.0) 15 (4.6)

Through the Roof 2 110 (33.5) 15 (4.6)

Through the Roof 3 105 (32.0) 15 (4.6)

Through the Roof 4 100 (30.5) 18 (5.5)

Page 7

Page 7

Venting Specifications for:

8

48 Gallon
65 Gallon

Specifications

Vent Tables

3" Diameter (7.6 cm) PVC Vent Connector Lengths

Terminating

Through the Wall

# of

Elbows

1 55 (16.8) 2 (.6)

Maximum Straight

Length ft (m)

Minimum Straight

Length ft (m)

Through the Wall 2 50 (15.2) 2 (.6)

Through the Wall 3 45 (13.7) 2 (.6)

Through the Wall 4 40 (12.2) 2 (.6)

Through the Roof 0 60 (18.3) 7 (2.1)

Through the Roof 1 55 (16.8) 7 (2.1)

Through the Roof 2 50 (15.2) 7 (2.1)

Through the Roof 3 45 (13.7) 7 (2.1)

4" Diameter (10.2 cm) PVC Vent Connector Lengths

Terminating

Through the Wall

# of

Elbows

1 10 (3.1)

Through the Wall 2 10 (3.1)

Through the Wall 3 10 (3.1)

Through the Wall 4 10 (3.1)

Through the Wall 5 12 (3.6)

Maximum Straight

Length ft (m)

175 (53.3)

170 (51.8)

165 (50.3)

160 (48.8)

155 (47.2)

Minimum Straight

Length ft (m)

Through the Roof 0 15 (4.6)

Through the Roof 1 15 (4.6)

Through the Roof 2 15 (4.6)

Through the Roof 3 15 (4.6)

Through the Roof 4 15 (4.6)

Page 8

180 (54.9)

175 (53.3)

170 (51.8)

165 (50.3)

160 (48.8)

Page 8

Control Timings

A

9

Ignition State Timing

Pre-purge 2 Seconds

Trial for Ignition 90 Seconds

Flame Stabilization Period 3 Seconds

Inter-purge 15 Seconds

Flame Failure Response Time 1.5 Seconds (2 second. Maximum; 1 second minimum.)

Post-purge 15 Seconds

PS Fault Delay (failed open/close) Retry after 2 Minutes

Soft Lockout Retry after 5 Minutes

TCO Limit Lockout Indefinite (See Page 24 to reset)

Verify Resistive Delay Retry after 2 Minutes (repeats 5 times)

Simulated Resistive Load Lockout Indefinite (cycle power to reset)

Hardware Error Lockout Indefinite (self clears if fault clears for at least 15 seconds)

Specifications

Pilot

Pilot

Wiring Diagram

Wiring Diagram

Blower

Blower

Housing

Housing

B

B

Thermal

Thermal

Well

Well

Blower

Blower

Temperature

Temperature

Switch

Switch

Pressure

Pressure

Switch

Switch

C

C

Simulated

Flammable

Resistive

Vapor

Device

Sensor

Blower

Blower

Motor

Motor

Page 9

Page 9

Sequence of Operation

10

1

Start Up.

Upon power up, the control runs a safe-start check with a typical start-up delay of 5 seconds.

2

Flammable Vapor.

To assure no outputs are energized if the “Flammable Vapor Sensor” is out of range, the control will test the
“Flammable Vapor Sensor” for proper operating range. If the “Flammable Vapor Sensor” is within range the
control resumes normal operation with no perceptible delay. If the “Flammable Vapor Sensor” is out of range,
the control LED immediately flashes 7 times with 3 second pause.

1

Thermostat calls for heat.

Prior to energizing blower, gas control checks safety circuit to insure the circuit is open. Normal switch positions
in the safety circuit are as follows:

a) Pressure switch normally open.
b) Blower temperature switch normally closed.

If the safety circuit is closed, the control waits 4 seconds, gas control LED flashes 2 times with 3 second pause.
Gas control waits 2 minutes then, blower runs for 30 seconds. This cycle repeats until safety circuit opens.

2

Blower energizes.

3

Pressure switch proves blower/vent system operation.

If the pressure switch does not close within 30 seconds, the control LED Flashes
The blower runs for 30 seconds every 2 minutes trying to get the pressure switch or blower temperature switch to
close. This cycle repeats as long as there is a call for heat.

4

Blower pre-purge period (2 seconds)

5

Trial for pilot ignition (90 seconds).

a) The gas control lights the pilot by activating spark igniter and gas flow to pilot burner.
b) If flame is not sensed within 90 seconds, igniter and gas flow are deactivated, blower will post purge and
control LED flashes 6 times with 3 second pause.

6

Main burner Ignition

After pilot flame is sensed, gas control activates main valve for main burner ignition. The gas control will ignore
flame and pressure switch signals for 3 seconds allowing for main burner to stabilize.

.3 times with 3 second pause

Page 10

Page 10

Steady state operation.

11

7

During Steady State Operation the Control Monitors:

Thermostat temperature sensor-

blower will post purge for 15 seconds. Control LED flashes a short flash once every 4 seconds (idle) status
code.

Sequence of Operation

When set point temperature is satisfied, gas valve is shut down and

Pressure switch / Blower temperature switch-

If either switch opens, pilot valve and main valve is shut
down. The blower continues to runs for 30 seconds attempting to close the circuit. The control LED Flashes
3 times with 3 second pause.

Flame Sensor-

If flame is lost, pilot & main valve are shut down, blower runs for 15 seconds. Control attempts
to re-light pilot 4 times. If unsuccessful, Blower is shut down and control proceeds to 5 minute lockout. Control
re-attempts to light pilot starting at normal heating sequence #2.

8

Thermostat satisfies

9

Burner off.

10

Blower post purge (15 seconds).

(Control LED flashing once every 4 seconds).

1. Flammable Vapor Sensor Fault:

a) If the resistance is greater than 70,000 Ohms - the gas control immediately turns off all outputs. Control waits

and monitors resistance for 30 seconds. If the resistance is greater than 65,000 ohms after 30 seconds, the
gas control proceeds to verify resistive delay for 2 minutes and flashes 7 times then once with a three second
pause. This process is repeated 5 times until the control either returns to normal operation or proceeds to

flammable vapor lockout.

b) If the resistance is below 3000 ohms - The gas control immediately turns off all outputs and proceeds to flash

8 times then once with three second pause. The error self clears if the resistance returns to normal range for at
least 15 seconds.

2. Temperature Sensor Fault:

a) Temperature sensor detected open circuit - The gas control Immediately turns off all outputs and proceeds to

flash 8 times then three times with three second pause. The error self clears if the fault clears for at least 15 seconds.

b) Thermal well sensors not reading the same temperature within ±5.5 °F - The gas control Immediately turns off

all outputs and proceeds to flash 8 times then three times with three second pause. The error self clears if the fault
clears for at least 15 seconds.

c) Water temperature in excess of TCO (Temperature Cut Off) limit - The gas control immediately turns off pilot

main valve and proceeds to flash 4 times with 3 second pause. Blower continues to run until gas control is reset.
To reset control, rotate knob of temperature control to the minimum setting for at least 6 seconds before returning
to desired temperature setting.

Page 11

Page 11

Sequence of Operation

12

3. Pressure Switch/Blower Temperature Fault:

a) Pressure switch closed at start of call for heat - The gas control waits four seconds then, proceeds to flash

2 times with 3 second pause. The control waits 2 minutes and then turns on blower for 30 seconds. The blower
turns off after 30 seconds and the control waits for pressure switch to open. Any time the Pressure switch opens,
the blower turns on (or stays on) and the control proceeds to waiting for pressure switch to close.

b) Pressure switch or blower temperature switch failed to close - The gas control runs the blower for 30 seconds

waiting for the pressure switch and/or blower temperature switch to close. If either switch does not close in 30
seconds, the blower turns off and the control flashes 3 times with 3 second pause. The gas control waits two
minutes before turning on the blower for another 30 seconds to see the circuit close. This cycle repeats as long as
there is a call for heat or until the circuit closes.

c) Pressure switch or blower temperature switch opens during burner operation - The gas control turns off the

pilot and main valve, runs blower for 15 seconds (inter-purge) waiting for pressure switch and/or blower
temperature switch to close. If either switch fails to close, the control proceeds as described in 3b above. If the
circuit closes again by the end of the inter-purge, the recycle counter is incremented, if the recycle count has
not reached its limit (4), another trial for ignition begins. If the recycle count has been reached, the gas control
turns off the blower and flashes 6 times then 2 times with 3 second pause. The gas control waits 5 minutes before
repeating ignition sequence.

4. Trial For Ignition Fault:

a) Pressure switch opens during trial - The gas control turns off igniter and pilot valve. The gas control proceeds

as described in 3b above. If the pressure switch closes within 30 seconds the gas control will continue with trial for
ignition starting at blower pre-purge.

b) Flame Not Sensed - The gas control energizes the spark igniter attempting to light the pilot and prove flame. If

flame is not sensed within 90 seconds, the igniter turns off, the pilot valve is closed and the gas control runs the
blower through post purge and flashes 6 times then once with 3 second pause. The control waits 5 minutes before
repeating the ignition sequence.

5. Flame Sensing Fault:

b) Flame lost during run - The gas control turns off pilot and main valves, runs blower for 15 seconds (inter purge).

The gas control increments the recycle count, if the recycle count has not reached its limit (4), another trial for
ignition begins. If the recycle count has been reached, the gas control turns off the blower and flashes 6 times
then 3 times with 3 second pause. The gas control waits 5 minutes before repeating the ignition sequence.

c) Flame sensed out of sequence - the gas control only looks for pilot flame when the blower is running. If flame is

present when the pilot valve is not open, the gas control proceeds to wait for flame loss and flashes 5 times with 3
second pause. This continues until flame is lost, once the flame signal is lost, the control flashes 6 times then 4
times with 3 second pause. The control waits 5 minutes before repeating the ignition sequence.

Page 12

Page 12

Observe green LED indicator on

13

Electronic gas control. Error flash codes
are displayed with a three second pause
before repeating. Check and repair the
system as noted in the troubleshooting
table below.

Troubleshooting

Green LED

Indicator

LED Status

None, control LED not
on or flashing

Short flash, once every
four seconds

“Heartbeat”, alternates
bright/dim

Short flash once per
second

Two flash, three
second pause

Three flash, three
second pause

Four flash, three
second pause

Five flash, three
second pause

Control

Status

No electrical
power

Stand-by mode,
Waiting for call for
heat (no fault).

Thermostat calling
for heat (no fault).

Weak pilot signal
on last call for
heat.

Pressure switch
not working­closed position.

Pressure switch
or blower temp.
switch not working

-open position.

Excessive tank
temperature.
System must be
reset. (See Pg. 24)

Undesired-false
pilot flame
present.

Probable Cause

Control power switch in “OFF” position.
Supply voltage interrupted.

Temperature demand is satisfied

Tank temperature below set point of thermostat.

1. Unstable pilot.

2. Pilot tube block or restricted.

3. Oxidation build up on pilot electrode.

4. Wire damage to pilot assembly or bad
connection at gas valve.

1. Pressure switch tubing kinked or blocked.

2. Blocked pressure tap on switch or blower.

3. Faulty pressure switch.

1. Vent blockage or improper vent configuration.

2. Pressure switch tubing kinked or blocked.

3. Faulty pressure switch.

4. Blower not spinning up to speed.

5. Blower temp or exhaust temp too high

6. Faulty blower temperature switch.

1. Thermal well sensor out of calibration.

2. Faulty gas control.

3. Pluming leak.

4. Tank not filled with water.

1. Pilot valve stuck in open position.

Service

Procedure

Turn power on

Normal operation.

Adjust thermostat to

temp level

Normal operation.

Adjust thermostat to

temp level

1. Page 15

2-4. Page 17

Page 18

1. Check vent or vent tables.

2 & 3 Page 18

4. Page 20

5 & 6 Page 22

1. Page 24

2. Replace gas control,
page 24

Replace gas control,
page 24

Page 13

Page 13

Troubleshooting

14

LED Status

Six-one flash, three
second pause

Six-two flash, three
second pause

Six-three flash, three
second pause

Six-four flash, three
second pause

Seven flash, three
second pause

Eight-one flash, three
second paus

Control

Status

Failed to light
pilot.
System auto
resets.

Pressure switch
or blower temp
switch opened
during burner
operation.
System auto
resets.

Pilot flame
extinguished.
System auto
resets.

Undesired-false
pilot flame
sensed.
System auto
resets.

Flammable
Vapor Sensor
fault detected.

Flammable
Vapor Sensor
out of
specification.

Probable Cause

1. Unstable pilot.

2. Pilot tube blocked or restricted.

3. Oxidation build up on pilot electrode.

4. Wire damage to pilot assembly or bad
connection at gas valve.

1. Vent blockage or improper vent configuration.

2. Pressure switch tubing kinked or blocked.

3. Faulty pressure switch.

4. Vent termination being affected by wind

5. Blower not spinning up to speed.

6. Blower temp or exhaust temp too high

7. Faulty blower temperature switch.

1. Unstable pilot.

2. Pilot tube blocked or restricted.

3. Oxidation build up on pilot electrode.

4. Wire damage to pilot assembly or bad
connection at gas valve.

5. Insufficient combustion air.

6. Gas pressure is out of specification.

Pilot valve stuck in open position.

WARNING: EXPLOSION HAZARD

• Indicates gasoline vapors were detected at potentially
explosive levels.

• Verify no gasoline vapors are still present.

• Reset the control by cycling power to the appliance or by
cycling the ON/OFF switch.

• Replace the Flammable Vapor Sensor element if a gasoline
spill event occurred.

• Very Flammable Vapor Sensor (FVS) resistance is not below
25 KΩ.

• Check wiring to FVS and insure it is not shorted.

• Replace control if everything above checks out OK.

Service

Procedure

1. Page 15

2-4. Page 17

1. Check vent or vent tables.

2 & 3 Page 18

4. Refer to venting section of
installation manual

5. Page 20

6 & 7 Page 22

1. Page 15

2-4. Page 17

5. Refer to installation manual

Replace gas control,
page 26

Page 28

Page 28

Eight-three flash, three
second pause

Eight-four flash, three
second pause

Page 14

Thermal well
sensor damaged
or unplugged

Gas valve fault
detected.

1. Damage to thermal well wire.

2. Thermal well sensor resistance out of range.

1. Control needs to be reset.

2. Control is wet or physically damaged.

Page 24

1. Interrupt power supply

2. Replace gas control,
page 26

Page 14

TTW SERVICE PROCEDURE I

15

Burner Operation Inspection,

Adjustment, Cleaning and Replacement

Burner Inspection and Air Shutter Adjustment.

At periodic intervals (every 6 months) a visual inspection should be made of the pilot and main burner for proper
operation and to assure no debris is accumulating.

Pilot flame should be stable, some causes for an unstable pilot flame are:

a) Water heater vent is less than the allowable vent length.
b) Gas pressure is out of specification.
c) Pilot flame not fully engulfing spark/flame sensor.

Main burner should light smoothly from pilot and burn with a blue flame with a minimum of yellow tips.

Steel burner models self adjust air to gas ratio mixture and do not have an adjustable air shutter. Cast iron burner can
have the gas and air mixture properly proportioned by adjusting the air shutter on the mixer face of the main burner
(see cast iron burner adjustment below).

Main burner must be free from any debris accumulation that may effect burner operation (see burner cleaning
procedure on page 16).

Cast Iron Burner Air Shutter Adjustment

WARNING

Inner door and burner components may be HOT when performing this operation. Take

necessary precaution to prevent personal injury.

Step 1. With main burner in operation, remove outer jacket door and inner door per service procedure XIII on

page 34.

Step 2. To adjust for proper burning, loosen the air shutter nut, rotate the air shutter to close the opening in the

burner, then slowly rotate the air shutter open until flame becomes as blue as possible with a minimum of
yellow tips. Tighten the air shutter nut.

Too much air will cause the flame to lift off the burner ports and create noisy burner operation.
Too little air will result in soot formation.

Step 3. Reinstall inner door and observe burner operation. Burner should operate as adjusted in step 2. If not,

repeat air shutter adjustment compensating for proper burner operation with inner door closed.

Air Shutter Nut

Air Shutter Nut

Air Shutter

Air Shutter

Page 15

Page 15

TTW SERVICE PROCEDURE I

Burner Cleaning

Step 1. Position gas control power switch to the

“OFF” position and unplug heater from wall
outlet.

Step 2. Turn off gas supply to water heater.

Step 3. Remove outer jacket door and inner door per service

procedure XIII on Page 34.

Step 4. Disconnect pilot tube (7/16 wrench) and

feedline (¾ wrench) from gas control.

Step 5. Disconnect igniter/flame sensor wire from gas control.

Step 6. Remove burner assembly from combustion chamber.

Step 7. Thoroughly inspect burner surface area and burner port area and

remove any loose debris.

16

Burner Operation Inspection,

Adjustment, Cleaning and Replacement

Burner Cleaning

Remove Outer

door.

Step 1. Position gas control power switch to the

“OFF” position and unplug heater from wall
outlet.

Step 2. Turn off gas supply to water heater.

Step 3. Remove outer jacket door and slide inner door open from left to

right.

Step 4. Disconnect pilot tube (7/16 wrench) and

Igniter/flame

sense wire

feedline (¾ wrench) from gas control.

Step 5. Disconnect igniter/flame sensor wire from gas control.

Step 6. Remove burner assembly from combustion chamber.

Step 7. Thoroughly inspect burner surface area and burner port area and

remove any loose debris.

Step 8. For cast iron burners, inspect for any debris build up inside

burner casting.

Burner

surface area

Slide inner door open

from left to right.

Feedline nut

Pilot tubing nut

Burner

port area

Step 9. Unscrew burner from main burner

orifice. On cast iron burners, loosen
air shutter nut and unscrew feedline

Step 10. Remove main burner orifice from

from burner.

feedline (½" wrench on steel
burners, 3/8" wrench on cast iron)
inspect orifice, clean or replace if
necessary.

Step 11. Reassemble burner and reinstall into water heater. Restore gas supply

and check for gas leaks.

Step 12 To resume operation follow the instruction located on the lighting

instruction label or the lighting instruction located in the installation
and operating manual.

Page 16

Main burner

orifice

L.P. Main burner
orifice. Left hand

thread

Page 16

TTW SERVICE PROCEDURE II

Pilot Inspection, Testing and Replacement

Step 1. Position gas control power switch to the

“OFF” position and unplug heater from wall
outlet.

Step 2. Turn off gas supply to water heater.

Step 3. Remove outer jacket door and inner door per service

procedure XIII on page 34.

17

Pilot testing, Cleaning and Replacement

Pilot Inspection, Testing and Replacement

Step 1. Position gas control power switch to the

“OFF” position and unplug heater from wall
outlet.

Step 2. Turn off gas supply to water heater.

Step 3. Remove outer jacket door and slide inner door open from left to

right.

Remove Outer

door.

Igniter/flame

sense wire

Slide inner door open

from left to right.

Step 4. Disconnect pilot tube nut (7/16 wrench) and feedline nut

(¾ wrench) from gas control.

Step 5. Disconnect igniter/flame sense wire from gas control.

Step 6. Remove burner assembly from combustion chamber.

Step 7. Remove pilot assembly from feedline (¼" nut driver).

Step 8. Visually inspect igniter/flame sense wire for damage. Replace

pilot if damage is found.

Step 9. With a multi-meter set to the ohms setting, check continuity

through igniter/flame sense wire. Replace pilot if no continuity.

Step 10. Visually inspect igniter/flame sense electrode for deterioration.

Replace pilot as necessary. Electrode should not be in contact
with pilot hood, If so, carefully adjust electrode to a gap
distance of 3/32" (.09) from pilot hood.

Step 11. Visually inspect igniter/flame sense electrode for oxidation

build up. Carefully clean any oxidation using very fine emery
cloth.

Step 12. Visually inspect pilot tubing for kinks or cracks. If damage is

found replace pilot.

Ferrule

nut

Pilot

tubing

Igniter/flame

sense wire

Pilot

orifice

Feedline nut

Pilot tubing nut

Pilot

hood

Igniter/flame

sense electrode

Step 13. Inspect pilot tubing and pilot orifice for blockage:

a) Remove ferrule nut from bottom of pilot assembly (7/16" wrench).
b) Remove pilot tube and pilot orifice.
c) Inspect pilot tubing and pilot orifice for blockage. Clean
or replace as necessary.

Step 14. Reassemble pilot and install to feedline. Reinstall burner assembly to water heater. Restore gas supply

Step 15 To resume operation follow the instruction located on the lighting instruction label or the lighting

and check for gas leaks.

instruction located in the installation and operating manual.

Page 17

Page 17

TTW SERVICE PROCEDURE III

18

Pressure Switch Testing and

Replacement

Pressure Switch Testing

WARNING

115 volt potential exposure. Use caution

Step 1. Position power switch on gas control

making voltage checks to avoid personal injury.

to the “OFF” position.

Step 2. Remove the three screws (Phillips screw driver) from control access cover on blower assembly and

remove cover (see photo 1).

Step 3. Carefully remove pressure switch from blower housing (see photo 2)

With steps 1,2 & 3

complete,

disconnect wire leads from

pressure switch.

Use a multi-meter set to the

ohms setting. With blower off,

check across pressure

switch terminals.

Are switch contacts open?

(no electrical continuity)

Y

1

Pressure switch

wire leads

N

Check tubing and pressure
tap on switch for blockage.

Is there blockage?

Y

Slide pressure switch in direction
of arrow while tilting slightly away
from blower housing.

N

Replace switch

(see page 19)

2

Pressure Switch

Position gas valve power

switch to the “ON” position

and adjust thermostat

to call for heat,

this will start the blower.

Check with multi-meter, do

pressure switch contacts

close with blower running?

Y

Switch contacts are OK.

See safety circuit trace

(page 29)

Check tubing and

N

pressure tap on

switch for blockage.

Is there blockage?

Page 18

Clear blockage

Y

N

Y

Is vent
system

blocked

Is vent system length

N

within vent table

specifications

listed on pages 7 & 8

N

Reconfigure vent

system to be

compliant with

vent tables.

Y

See blower testing

Y

(page 20)

Is blower OK?

N

Correct blower

problem.

Page 18

TTW SERVICE PROCEDURE III

19

Pressure Switch Testing and

Replacement

Pressure Switch Replacement

WARNING

115 volt potential exposure. Use caution

to avoid personal injury.

Step 1. Position gas control power switch

to “OFF” position.

Step 2. Remove the three screws (Phillips screw driver) from control access cover on blower assembly and

remove cover (see photo 3).

Pressure Switch

3 4

Step 3. Carefully remove pressure

switch from blower
housing (see photo 4)

Slide pressure switch in direction
of arrow while tilting slightly away
from blower housing.

Step 4. Disconnect tubing from

5

pressure switch.
(see photo 5)

6

Step 5. Disconnect yellow wires

from pressure switch
(see photo 6)

Step 6. Reconnect wires from step 5 to new pressure switch.

Step 7. Reconnect tubing to new pressure switch.

Step 8. Carefully position pressure switch into blower housing.

Step 9. Position gas control power switch to “ON” position and verify proper heater operation.

Step 10. Replace control access cover from step 2.

Page 19

Page 19

TTW SERVICE PROCEDURE IV

20

Blower Testing and Replacement

Blower Testing

115 volt potential exposure. Use caution when

making voltage checks to avoid personal injury.

Step 1. Position gas control power switch

to “ON” position and adjust control to call for heat.

Step 2. Remove the three screws (Phillips Screw driver)

from control access cover on blower assembly and
remove cover (see photo 7).

Does blower energize

Within 2 minutes?

N

8 9

Does blower energize after

2 minutes, run for 30

seconds and shut down?

N

pressure switch

Y

tubing from blower.

(see photo 8)

Pressure tap

Pressure

switch tubing

Y

See pressure

switch testing

Disconnect

Page 18

manometer to

pressure tap of

(see photo 8)

Determine voltage

problem and correct.

7

Connect

blower.

11 12

Disconnect vent

system from top of

blower and remove

With blower running, and exhaust

adapter removed from top of

pressure of -2.15" to -2.30" W.C.?

N

WARNING

vent adapter.

(see photo 10)

blower, is there a negative

N

Is there 115vac across

blue and green wires

(see photo 13)

Y

Y

Remove exhaust

adapter

10

Blower OK

Replace blower

Disconnect cord set
shown in photo 9. Is

there 115VAC across

terminals shown in

photo 11

N

Is there 115 VAC

at wall outlet?

Y

Check power cord

for damage.

N

Replace blower

Y

N

Y

Is there 115VAC

across terminals

shown in photo 12 ?

Incorrect supply

voltage polarity

Determine

power source

problem and

correct.

Repair or replace

power cord

Page 20

Y

Reconnect cord set

N

Replace
cord set

shown in photo 9, is

there 115VAC between

blue wire and green

ground wire

(see photo 13)

N

Does cord set

N

have electrical

continuity?

Y

Replace

gas control

Y

Replace blower

Green ground

wire

Shown with pressure

switch removed.

13

Blue wire

Page 20

Blower removal

21

Step 1. Position gas control power switch to the “OFF” position.

Step 2. Unplug blower power cord from wall outlet.

Remove exhaust

adapter and retain for

use on new blower.

Step 3. Disconnect vent system from exhaust adapter on top of

blower.

Step 4. Remove exhaust adapter from blower (blade screw driver)

and retain for use on new blower

Step 5. Unplug cord sets from blower.

Step 6. Remove the three blower mounting screws

(¼" nut driver).

TTW SERVICE PROCEDURE IV

Blower Testing and Replacement

Blower Mounting

Screws

Step 7. Remove blower with gasket from water heater.

Blower Installation

Step 8. Clean any debris from jacket head of water heater.

Step 9. Set new blower with gasket in place using locating pins on

blower flange to line up with location holes in jacket head.
Be sure not to damage gasket.

Step 10 Secure blower in place using mounting screws from step 6.

Step 11. Re-install exhaust adapter from step 4.

Step 12. Reconnect vent system to

exhaust adapter.

Step 13. Reconnect cord sets from step 5.

Step 14. Plug blower power cord into wall outlet.

Step 15. Position gas control power switch to the “ON” position.

Locating Pins

on blower flange

Pin location holes in

jacket head

Blower

Cord Sets

Step 16. Verify proper blower operation.

Page 21

Page 21

TTW SERVICE PROCEDURE V

22

Blower Temperature Switch Testing

and Replacement

Blower Temperature Switch
Testing.

Step 1. Position power switch on gas control

to the “OFF” position.

Step 2. Remove the three screws (Phillips screw driver) from

control access cover on blower and remove cover (see
photo 14).

Step 3. Locate blower temperature switch (see photo 15)

Switch Setting

Opens on rise @ approximately 165°F

Auto resets on fall @ approximately 130°F

Cool switch to

below 130°F

115 volt potential exposure. Use caution

WARNING

to avoid personal injury.

15

Air mixing inlet

Blower temperature

14

switch location

Disconnect wire leads to

switch. Using a multi-meter

set to the ohms setting, is

there continuity between

the switch terminals?

Y

Reconnect wire leads and
observe heater operation.

Do exhaust gas

temperatures rise to or

above 170°F

with vent connected?

N

Do switch

contacts open?

N

Switch OK

N

Y

Replace switch

Y

contacts open?

Replace switch

(see page 23)

(see page 23)

N

Do switch

Y

Exhaust

temperature is

too hot.

Common causes for

high exhaust temperature

1. Vent length is below minimum allowable.

2. Vent diameter not to specification.

3. Restricted dilution air inlet.

4. Missing or deteriorated flue baffle.

5. Gas pressure is out of specification.

Page 22

Page 22

TTW SERVICE PROCEDURE V

23

Blower Temperature Switch Testing

and Replacement

Blower Temperature Switch
Replacement.

Step 1. Position gas control power switch to the “OFF” position

and unplug heater from wall outlet.

Step 2. Remove the three screws (Phillips screw driver) from the

control access cover on blower and remove cover.
(see photo 16)

Step 3. Locate blower temperature switch (see photo 17)

Step 4. Disconnect red and yellow wire leads from switch.

WARNING

115 volt potential exposure. Use caution

to avoid personal injury.

16

17

Blower temperature

switch location

Step 5. With an appropriate tool such as side cutters, snip the

retaining lug from the blower housing to allow removal of
temperature switch (see photo 18).

Step 6. Remove switch from blower housing.

Step 7. Install new switch. Be sure switch is properly seated in

mounting area.

Step 8. Reconnect red and yellows wires to new switch. Wires are

interchangeable with either terminal.

Step 9. Position gas control power switch to the “ON” position

and verify proper heater operation.

Step 10. Replace control access cover from step 2.

18

Snip retaining lug

from blower housing

Page 23

Page 23

Gas Control Testing

24

See pages 29 & 30 for gas control
voltage testing.

TTW SERVICE PROCEDURE VI

Gas Control/Thermal Well Testing and

Replacement

Thermal Well Testing

If Control has gone into TCO lockout due to

excessive tank temperature (four flash, 3 second

pause) reset control by rotating knob of temperature

control to the minimum setting for at least 6 seconds

before returning to desired temperature setting.

Observe heater operation. If control

continues to lockout due to

excessive tank temperature,

proceed to thermal well testing to

determine cause.

Thermal well testing

Position gas control power switch to

the “OFF” position and disconnect

thermal well harness from gas

control.

Using a multi-meter set to the

Ohms setting, determine the

resistance of thermal well sensor

(see caution photos 19 & 20)

Disconnect thermal

well wire harness

19

20

CAUTION

DO NOT use standard multimeter probes for this test.
Doing so will damage connector. Use special pin type
electronic probes or small diameter wire pins inserted
into connector.

Using a multi-meter set to the ohms setting, insert one meter probe (see caution)
into center wire position of thermal well connector, insert the second probe (see
caution) into either of the outside wire positions (see photo 19).

Once the thermal well resistance values are known, the water

temperature must also be known to determine if the resistance

values are correct. See page 25 to obtain water temperature.

Are thermal well resistance values correct?

Y

Replace gas control

(see page 26)

Page 24

Alternate the probe on the outside position to the opposite outside wire position
(see photo 20).

N

Replace thermal well

(see page 26)

Page 24

TTW SERVICE PROCEDURE VI

25

Gas Control/Thermal Well Testing and

Replacement

WARNING

Stored water may be HOT

when performing the following steps in this procedure.

Take necessary precaution to prevent personal injury.

Determine Water Temperature Inside Tank

Note: It is important to understand once the resistance for the thermal well is determined from page 24, water flow

through the heater should not occur. Prior to performing the steps below, turn off the cold water supply to the
water heater. This will prevent cold water flow into the tank affecting the resistance value of thermal well.

Step 1. Position gas control power switch to “OFF” position.

Step 2.

Draw approximately 1 quart of water from drain valve into container and immediately measure water
temperature using an accurate thermometer. It may be necessary to open a hot water faucet to allow
heater to drain.

Step 3. Using the chart below, determine correct resistance value for the water temperature from step 2.

Example: If temperature of water is 84°F, then the resistance through the sensor would be

8449 (see shaded area). NOTE: Sensor resistance increases as the temperature
falls.

Sensor Resistance at Various Temperatures

In Degrees F

°F012345678 9
40 26109 25400 24712 24045 23399 22771 22163 21573 21000 20445
50 19906 19383 18876 18383 17905 17440 16990 16553 16128 15715
60 15314 14925 14548 14180 13823 13477 13140 12812 12494 12185
70 11884 11592 11308 11032 10763 10502 10248 1000 9760 9526
80 9299 9078 8862 8653 8449 8250 8057 7869 7685 7507

90 7333 7165 7000 6839 6683 6531 6383 6238 6098 5961
100 5827 5697 5570 5446 5326 5208 5094 4982 4873 4767
110 4663 4562 4464 4368 4274 4183 4094 4006 3922 3839
120 3758 3679 3602 3527 3453 3382 3312 3244 3177 3112
130 3048 2986 2925 2866 2808 2752 2697 2643 2590 2538
140 2488 2439 2391 2344 2298 2253 2209 2166 2124 2083
150 2043 2004 1966 1928 1891 1856 1820 1786 1753 1720
160 1688 1656 1625 1595 1566 1537 1509 1481 1454 1427
170 1402 1376 1351 1327 1303 1280 1257 1235 1213 1191
180 1170 1150 1129 1110 1090 1071 1053 1035 1017 999
190 982 965 949 933 917 901 886 871 857 842
200 828 814 801 788 775 762 749 737 725 713

Page 25

Page 25

TTW SERVICE PROCEDURE VI

26

Gas Control & Thermal Well Testing

and Replacement

Gas Control & Thermal Well Removal From Water Heater

Gas Control

Gas Control

Step 1. Position gas valve power switch to the “OFF”

position and Unplug Heater from power supply.

Thermal

Thermal

Well

Well

Step 2. Drain heater to a point below the gas

control level.

Step 3. Turn off gas supply to water heater and

disconnect gas piping from gas control.

Step 4. Disconnect wire harnesses and burner assembly

from gas control.

Step 5. Remove gas control & thermal well by rotating flats of Thermal Well counter clockwise (1-5/16"wrench).

Gas Control Removal From Thermal Well

Follow the steps below allows removal gas control from thermal well without
removing thermal well from tank.

Step 1. Position gas control power switch to the “OFF” position and unplug water heater from power supply.

Step 2. Turn off gas supply to water heater and disconnect gas piping from gas control.

Step 3. Disconnect wire harnesses & burner assembly from gas control.

Step 4. Using gas control service tool (239-45991-00) available from your BWC parts supplier, Insert tool into

back of gas control (see photos below)

Insert tool from
back of control

Service tool shown

inserted in to back

of control

Step 5. Pivot tool towards heater as far as possible (see photo below). Lift straight up on gas control. The

control should move about 1/8". At this point, remove tool not allowing the control to fall back. With
tool removed, lift straight up on control to remove completely from Thermal Well.

With service tool inserted, pivot tool back towards

heater as far as possible. Lift straight up on control,

control will move 1/8". Remove tool and continue to lift

straight up on control to remove from Thermal Well.

Page 26

View from back of

control for clarity

Page 26

Gas Control Assembly to Thermal Well

27

Step 1. Install threaded end of thermal well into tank. Be sure

thermal well flange is positioned as shown in photo 24
for proper control alignment.

Step 2. Route wire leads back into relief opening.

(see photo 24)

Step 3. Align slots located on thermal well flange with tabs

located on back of gas control (see photos 24 & 25)

TTW SERVICE PROCEDURE VI

Gas Control & Thermal Well Testing

and Replacement

24

Thermal well
flange slots

Step 4. Carefully push control back onto thermal well flange

as far as possible towards water heater. Slide control
down to lock into position.

Step 5. Install burner and connect pilot and feedline to gas

control.

Igniter/sensor

Igniter/sensor

connection

connection

Step 6. Reconnect wire harnesses to gas control

Step 7. Reconnect gas piping to gas control.

Ground Wire

Ground Wire

connection

connection

Step 8. To resume operation, follow the

5 pin

blower harness connection

blower harness connection

5 pin

3 pin

3 pin

thermal well connection

thermal well connection

Route wires
through relief
opening

25

Gas control Tabs

per the illustration.

Restore gas supply and check for gas
leaks.

instruction located on the lighting
instruction label or the lighting instruction
located in the installation and operation
manual.

Flammable Vapor

Flammable Vapor

Sensor

Sensor

Page 27

Page 27

Flammable Vapor Device Testing

28

Step 1. Position power switch on gas control to the

“OFF” position.

Step 2. Disconnect flammable vapor sensor from

gas control.

Step 3. Using a multi-meter set to the ohms setting

check resistance of flammable vapor sensor.
(see caution below)
Resistance must be within 3,000 ohms and
48,000 ohms. If outside of this range replace
flammable vapor sensor.

TTW SERVICE PROCEDURE VII

Flammable Vapor Device Testing

Multi-meter set to
ohms setting

Electronic
“pin type”
Meter Probes

Flammable Vapor
Sensor

CAUTION

DO NOT use standard multimeter probes for this test.

Doing so will damage connector. Use special electronic

“pin type” probes or small diameter wire pins inserted

into connector.

Flammable Vapor
Sensor

Page 28

Page 28

TTW SERVICE PROCEDURE VIII

29

Safety Circuit Voltage Trace

Safety Circuit Voltage
Trace

NOTE: This procedure assumes a cool tank.

Remove three screws (Phillips Screw driver) from control access
cover on blower and remove cover (see photo 26).

Position gas control switch to the “ON”

position and adjust thermostat dial to call

for heat, Is there 10 to 13 VAC between

red wire leading to blower temperature

switch and green ground wire?

Blower must be running during this

voltage check.
(see photo 27)

Y

Is there 10 to 13 VAC between yellow

wire leading from pressure switch and

green ground wire?

(see photo 27)

Y

Is LED on gas valve flashing

N

N

the “heartbeat” code

(alternating bright/dim)

Verify 115VAC to gas
control (see page 30)

115 volt potential exposure. Use caution

making voltage checks to avoid personal injury.

N

Y

Is there continuity

through blower

temperature switch?

(see page 22)

WARNING

26

No voltage from gas control,

call for technical support.

Y

N

Check for loose or

broken wire

connection at switch

terminals

Do you hear or can you

see the igniter sparking?

Y

Safety circuit

voltage is OK.

If burner does not light,

observe LED flash code

on gas valve and refer to

troubleshooting section

on page 13

Determine cause of blower

Correct igniter/

sensor problem.

N

Check igniter/sensor

(see page 17)

is igniter/sensor OK?

27

Y

temperature switch

activation and correct.

Faulty cord set or

gas control.

Green ground wire

Red wire leading to

blower temp. switch

Yellow wire

leading from

pressure switch

Page 29

Page 29

TTW SERVICE PROCEDURE IX

30

115 VAC Trace

115 VAC Circuit Trace

115 volt potential exposure. Use caution

WARNING

making voltage checks to avoid personal injury.

Step 1. Verify 115VAC and proper polarity at wall outlet.

Step 2. With unit plugged in and control power switch in the “ON” position verify LED status.

LED status

None, Control LED not

on or flashing.

Disconnect cord set as

shown in photo 28

Using a volt meter set

to volts AC, is there

115VAC across

terminals shown in

photo 29 ?

Y

Is there 115VAC
across terminals

shown in photo 30 ?

N

Incorrect supply

voltage polarity

N

Y

LED status

Short flash, once every

four seconds.

Waiting for

call for heat.

28

Reconnect cord set

shown in photo 28.

Disconnect wire harness

from gas control

(see photo 31).

LED status

“Heartbeat”, alternates

bright/dim.

Thermostat calling

for heat

Check for damage to

AC supply power cord.

N

Replace Blower

29

Y

Wire harness

LED status

Various flashing error

codes.

Verify error code as

listed on page 13

30

Repair damage

31

Locate black & white wires at

connector, It may be necessary to pull

back wire sheath to identify wire colors.

(see photo 32)

Is there 115VAC

across black & white

wires as shown in

photo 32?

N

Call for technical

support.

Y

Replace gas

control.

Page 30

32

Wire sheath pulled back to

identify wire colors

Check for 115VAC between black & white wires.

-NOTE-

Electronic meter probes required. Use care not to

damage connector during this check.

Page 30

TTW SERVICE PROCEDURE X

31

Dip Tube

Inspection and replacement

Dip Tube Inspection and Replacement

WARNING

Water Heater components and stored water may be HOT

steps in this procedure. Take necessary precaution to prevent personal injury.

Step 1. Position on/off switch of gas control valve to “OFF” position and unplug water heater from wall outlet.

Step 2. Turn off cold water supply to water heater. Connect hose to drain valve of water heater and route to an

open drain. Open a nearby hot water faucet to vent heater for draining. Open drain valve of water
heater and allow heater to drain to a point below the inlet connection nipple.

Step 3. Disconnect inlet nipple from plumbing system.

Step 4 With an appropriate tool such as a pipe wrench, remove inlet nipple/dip tube from the water heater.

Use caution not to damage pipe threads.

when performing the following

Step 5. Visually inspect inlet nipple/dip tube. Inlet nipple/dip tube should be free of cracks and any blockage.

Hydro-jet slots should be open and free of any blockage.

Any damage such as cracks, restriction due to deformation or unintentional holes are not field
repairable and the inlet nipple/dip tube must be replaced.

Step 6. Upon completion of inspection or subsequent replacement, reinstall inlet nipple/dip tube into water

heater. Connect nipple to plumbing system, resume water supply and refill with water.

Step 7. To resume operation follow the instructions located on the lighting instruction label or the lighting

instructions located in the installation and operation manual.

Page 31

Page 31

TTW SERVICE PROCEDURE XI

32

Anode

Inspection and replacement

Anode Inspection and Replacement

WARNING

Water Heater components and stored water may be HOT when performing the following

steps in this procedure. Take necessary precaution to prevent personal injury.

Step 1. Position on/off switch of gas control valve to the “OFF” position and unplug water heater from wall

outlet.

Step 2. Turn off cold water supply to water heater. Connect hose to drain valve of water heater and route to an

open drain. Open a nearby hot water faucet to vent water heater for draining. Open drain valve of
water heater and allow water heater to drain to a point below the outlet connection nipple.

Step 3. Disconnect outlet nipple from plumbing system.

Step 4 With an appropriate tool such as a pipe wrench, remove outlet nipple/anode from the water heater. Use

caution not to damage pipe threads.

Step 5. Visually inspect outlet nipple/anode. Outlet nipple/anode should show signs of depletion, this is

normal. If depletion is ½ of the original anode diameter (approximately ¾” diameter), replacement is
recommended. If any of the steel core of the anode is exposed, replacement is recommended.

Step 6. Upon completion of inspection or subsequent replacement, reinstall outlet nipple/anode into water

heater. Connect nipple to plumbing system, resume water supply and refill with water.

Step 7. To resume operation, follow the instructions located on the lighting instruction label or the lighting

instructions located in the installation and operation manual.

Page 32

Page 32

Remove blower to gain access to

33

flue baffle

TTW SERVICE PROCEDURE XII

Flue Baffle

Inspection and replacement

Disconnect vent

system from exhaust

adapter.

Step 1. Position gas control power switch to the “OFF” position

and unplug blower from wall outlet.

Step 2. Disconnect vent system from exhaust adapter on top of

blower.

Step 3. Unplug cord sets from blower. (see photo 33).

Step 4. Remove the three blower mounting screws

(¼" nut driver) (see photo 33).

Step 5. Remove blower with gasket from water heater.

Step 6. Remove flue baffle from Heater (see photo 34).

Step 7. Inspect baffle for deterioration, missing restrictors.

Clean any scale or debris build up. Replace with new
baffle as necessary.

Step 8. Reinstall baffle into flue tube. Be sure baffle

hanger tab are inserted into notch location at the
top of the flue tube (see photos 35 & 36).

Step 9 Check Burner to insure no scale has accumulated during

this operation. See burner cleaning procedure on page 15.

Step 10. Reinstall blower on water heater. Connect vent

system and cord sets to blower. Plug water heater
into wall outlet.

33

Blower

Cord Sets

34

35

Blower Mounting

Screws

Flue Baffle

Step 11. To resume operation follow the lighting instruction

located on the lighting instruction label or the lighting
instruction located in the installation and operation
manual.

Flue tube

notch

36

Baffle shown

installed in flue

tube notch.

Page 33

Page 33

Inner Door Removal Procedure

34

Step 1. Position gas control power switch to the “OFF” position.

Step 2. Remove outer jacket burner access door

Step 3. Inner Door Removal.

a) Remove (2) 1/4" hex drive screws from right side inner door.
b) Remove (2) 1/4" drive screws from flange section of inner door.
c) Remove (2) 1/4" drive screws from left side inner door.
d) Remove inner door and inspect per step 4.

TTW SERVICE PROCEDURE XIII

Inner Door/Gasket Removal, Inspection

Replacement and Reinstallation

¼" Hex Drive Screws
Right and Left Side Inner Door.

¼" Hex Drive Screws at

Flange Area of Inner Door

Step 4. Fully inspect inner door gaskets for the following:

>Tears >Other imperfections that will inhibit proper seal
>Missing Material >Gasket adhesion to inner door
>Cracks >Material left on combustion chamber (around opening)
>Dirt or debris

If the gasket is not effected by any of the above, gasket replacement is not required. If replacement is

required,

proceed to Inner Door Gasket Replacement Procedure.

Inner Door Gasket Replacement
Procedure.

WARNING

If the information in these instructions is not

followed exactly, a fire or explosion may result causing

property damage, personal injury or death.

Step 5. After inspection of inner door as noted in step 4, completely remove gasket and adhesive residue from right

and left side inner doors as needed.

Step 6. Use RTV sealant (recommended bead size 1/8") to secure the inner door gasket to the inner door sections

(right & left). Refer to illustration on next page for proper application. Note the overlap configuration in the
flange area of the inner door. Set the flange section first, this will help to achieve the proper over lap position.

Page 34

Page 34

TTW SERVICE PROCEDURE XIII

35

Inner Door/Gasket Removal, Inspection

Replacement and Reinstallation

Installation of Inner Door With Gasket.

Step 7. Clean any residual gasket residue or other debris

from combustion chamber surface before
installing the inner door/gasket assembly.

Step 8. Place the left side inner door into position first.

Firmly position the radiused channel of the inner
door around the feedline. Using the 1/4” hex drive
screws from step 3c, secure left side inner door in
place. DO NOT OVER TIGHTEN SCREWS.

Step 9 Position pilot tube and igniter/sensor wire

against left side inner door flange gasket.

DO NOT ROUTE
CHANNEL WITH FEEDLINE.

THROUGH RADIUSED

WARNING

Stripped fastener connections may allow

for seal breach of inner door. A seal

breach may result in a fire or explosion

causing property damage, personal injury

or death. Do not over tighten screws in

steps 8, 10 and 11.

If a fastener connection is stripped,

contact the manufacturer listed on the

water heater rating plate.

Position pilot tubing and

igniter/sensor wire.

Radiused Channel

for Feedline

Page 35

Page 35

TTW SERVICE PROCEDURE XIII

36

Inner Door/Gasket Removal, Inspection

Replacement and Reinstallation

Step 10. Firmly place right side inner door flange against the left side inner door flange and secure with two ¼” drive

screws from step 3b. DO NOT OVER TIGHTEN SCREWS.

Step 11. Align right side inner door to combustion chamber and verify the fastener holes of the combustion

chamber are aligned with the right side inner door slotted opening. Verify seal integrity around
combustion opening. Secure right side inner door using 1/4” hex drive screws from step 3a. DO NOT
OVER TIGHTEN SCREWS. Verify both left and right sides of the inner door are properly positioned and
sealed against the combustion chamber.

Secure flange with

¼" drive screws.

Verify threaded hole

alignment with slotted

openings in inner door.

Step 12. Replace outer jacket burner access door.

Step 13. To resume operation follow the instructions located on the lighting instruction label or the lighting instructions

located in the installation and operation manual.

Page 36

Page 36

ScreenLok®Flame Arrestor Cleaning

37

ScreenLok®Flame Arrestor Cleaning:

Step 1. Position Gas Control Power Switch to the OFF position.

Step 2. Remove outer jacket.

Step 3. Remove inner door per TTW SERVICE PROCEDURE XIII, step 3a through step 3d.

Step 4. Disconnect main burner feed line (3/4 wrench), pilot tube (7/16 wrench) and igniter/flame sensor wire

from gas control and remove burner assembly from combustion chamber.

®

Step 5. Clean ScreenLok

scale or other debris accumulation. Using a soft brush, clear jacket openings from any dirt, dust,
restrictions or other obstructions.

Step 6. Remove any debris from burner assembly per TTW SERVICE PROCEDURE I and reinstall burner

assembly into combustion chamber.

Flame Arrestor using stiff brush, compressed air and/or shop vacuum to remove any

Step 7. Reconnect feedline, pilot tube and igniter/flame sensor wire to the gas control.

Step 8. Reinstalll inner door per TTW SERVICE PROCEDURE XIII, step 7 through step 12.

Step 9. To resume operation follow the instructions located on the lighting instruction label or the lighting

instruction located in the installation and operation manual.

Page 37

BTU British Thermal Units

38

GPM Gallons per Minute
Hz Hertz
KW/h Killo-watts per hour
LED Light Emitting Diode
NPT National Pipe Thread
Ohms Ohms of resistance
PSI Pounds per Square Inch
RPM Revolutions per Minute
TCO Temperature Cut Off
VAC Volts Alternating Current
W.C. Inches of Water Column
°C Degrees Centigrade
°F Degrees Fahrenheit

Glossary of Terms

NOTES

Page 38

Page 34

Parts List

39

1. Blower Complete

2. Air Mixing Inlet cover

3. Pressure Switch

4. Blower Temp. Switch

5. Blower Gasket

6. Blower Power Cord

7. Vent Adapter w/vent term.

8. Condensate Hose Kit

9. Flue Reducer (M2 only)

10. Heat Trap Outlet

11. Hot Water Outlet Anode

12. Flue Baffle

13. Heat Trap Inlet

14. Inlet Dip Tube

15. Wire Harness

16. T&P Valve

17. ¾ NPT Plug

18. Burner Assy. (Nat)

19. Burner Head

20. Main Burner Orifice

21. Pilot Assy. (Nat)

22. Pilot Orifice

23. Feedline

24. Burner Assy. (L.P.)

25. Cast Iron Burner

26. Pilot Assy. (L.P.)

27. Pilot Orifice (L.P.)

28. Feedline

29. Jam Nut

30. Air Shutter

31. Main Burner Orifice (L.P.)

32. Outer Door

33. Right Side Inner Door

34. Screw #8-15 x 3/4

35. Left Side Inner Door

36. Screw #10-12 x 3/4

37. Brass Drain Valve

38. Flammable Vapor Sensor Clip

39. Flammable Vapor Sensor

40. Sensor Harness

41. Thermal Well

42. Gas Control

43. Gas Control Service Tool

44. Kit-Gas Control

45. Inner Door Gasket Kit

46. ASSE App’vd Mixing Valve

47. Kit-Heat Trap Insert

Page 35

Page 39

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