Bradford-White U4TW50T'FRN User Manual

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TTW® Eco-Defender

Residential Ultra Low NOx Gas Water Heaters

SERVICE

MANUAL

Troubleshooting Guide and Instructions for Service

(To be performed ONLY by qualified service providers)

Models Covered

by This Manual:

U1TW40S*FRN

U1TW50S*FRN

U1TW60T*FRN

U4TW40T*FRN

U4TW50T*FRN

U4TW60T*FRN

U2TW50T*FRN

U2TW65T*FRN

UTW450S60FR*N

UTW465S60FR*N

(*) Denotes Warranty Years

(Model Shown: U-4-TW-40T6FRN)

Manual 238-48509-00A

Save this manual for future reference

Table of Contents

Section

Page

Introduction ______________________________________________5 How to Use this Manual _____________________________________6 Tools Required for Service ___________________________________7 Specifications _____________________________________________8 Sequence of Operation_____________________________________ 12

Power Up Sequence Normal Heating Sequence Abnormal Operation

Troubleshooting __________________________________________ 17 Burner Maintenance _______________________________________ 20

Burner Inspection

Burner Cleaning Procedure

Pilot Maintenance _________________________________________ 22 Pilot Inspection Testing and Replacement

Pressure Switch Testing and Replacement _____________________ 25 Blower Testing and Replacement _____________________________ 28 Blower Temperature Switch Testing and Replacement ____________ 31 Thermal Well Testing ______________________________________ 34 Determine Water Temperature Inside Tank_____________________ 35 Gas Control and Thermal Well Testing and Replacement __________ 36 Flammable Vapor Sensor Testing and Replacement ______________ 40 115 VAC Circuit Trace _____________________________________ 40 Safety Circuit Voltage Trace_________________________________ 42 Flue Baffle Inspection and Replacement _______________________ 43 Diptube Inspection and Replacement _________________________ 44 Anode Inspection and Replacement___________________________ 45 Inner Door Removal, Inspection and Replacement _______________ 46 Inner Door Gasket Replacement _____________________________ 47 Inner Door Installation_____________________________________ 48 ScreenLok ® Flame Arrestor Cleaning_________________________ 49 Common Terms __________________________________________ 50 Notes __________________________________________________ 50 Parts List _______________________________________________ 51

Page 2

2

x
x
x

WARNING

If the information in these instructions is not followed exactly, a fire or explosion may result causing property damage, personal injury, or death.

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.

x 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.

DANGER

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

CAUTION

Incorrect operation of this water heater may create a hazard to life and property and will nullify the warranty.

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.

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.

NOTICE

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.

Page 3

3

WARNING

Water heaters are heat producing appliances. To avoid damage or injury, do not store materials against the water heater or any of its components. Use proper care to avoid unnecessary contact, especially by children, with the water heater and its components. Under no circumstances must flammable materials, such as gasoline or paint thinner be used or stored in the vicinity of this water heater or in any location in which the fumes could reach the water heater.

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. To prevent the possibility of injury under these conditions, we recommend a 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.

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.

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.

Page 4

4

Introduction

The Bradford White ECO-DEFENDERSafety System®

The Bradford White ECO-DEFENDERSafety System was designed to resist the ignition of flammable vapors that can occur outside of the water heater and produce Ultra Low NOx emissions. Use and installation are nearly identical to previous versions of atmospherically fired and vented water heaters. A number of exclusive design features are incorporated in the system that will require additional knowledge on the part of the qualified service provider. The following information will instruct service professionals on the function, proper diagnosis, and repair of water heaters employing the Bradford WhiteECO-DEFENDERSafety System.

Introduction

The new Bradford White TTW ECO-DEFENDERwater 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, quiet operation, additional vent lengths, Bradford WhiteECO-DEFENDERSafety System ® and Ultra Low NOx emissions.

Spark-to-Pilot Ignition System - Employing thespark-to-pilotignition system promotes reliable and consistent pilot and main burner ignitions to provide hot water on demand.

Integrated Immersion Thermal Well/Gas Control 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 and FHSR performance.

The TTW1 (U1TW & U4TW), TTW2 (U2TW) & UTW4 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

Page 5

5

How to Use this Manual

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

How the Safety System Works

During normal operation, most air for combustion is drawn into the water heater through the openings in the jacket door. This air travels into the burner venturi, mixing with the gas jet. This air is then mixed with gas inside the burner and drawn to the burner screen and is efficiently combusted producing Ultra Low NOx emissions. Additional air is drawn through the openings in the jacket. This air travels down and around the combustion chamber and enters through holes in the bottom of the corrosion-resistantcombustion chamber. The air then travels up through the oriented flame arrestor plate louvers, where the velocity of the air is increased and its direction altered. The air then mixes in a normal manner with the combustion products from the burner.

In the case where trace amounts of flammable vapors are present in the air flowing into the combustion chamber and burner venturi, the vapors are harmlessly ignited by the burner / pilot flame. If flammable vapors are in sufficient quantity to prevent normal combustion, the burner and pilot flames are designed to shut down.

Should the flammable vapors continue to the burner, the flame arrestor plate and burner screen prevent the flames from traveling backwards and igniting vapors outside of the combustion chamber. This causes the thermopile to overheat and shuts down the main pilot and burner. The thermopile powers the intelligent diagnostic control which is capable of recognizing restricted airflow conditions caused by severe lint, dust and oil accumulation on the burner screen and arrestor plate. The intelligent diagnostic control will deactivate the burner and pilot in the unlikely event of restricted airflow.

How to Use this Manual

It is intended for this manual to be used by qualified service personnel for the primary purpose of troubleshooting and repair of the Bradford White Residential Flue Damper 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.

Page 6

6

Tools Required

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

Tools Required for Service

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-ampsand ohms.

Electronic Probes: In some cases, standardmulti-meterprobes will damage or simply not be effective to obtain certain voltage and ohm reading. It will be necessary to have special electronic “pin” typemulti-meterprobes. 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 number239-45991-00.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 wrenches (3/8", 7/16", 1/2"), 12" crescent wrench, Allen wrench set, screw drivers (common & Phillips), 1/4" nut driver, pliers (common & needle nose), socket set, side cutters, wire cutters, wire strippers, wire crimpers, torpedo level, small shop vac, step ladder, flashlight, and 5 gallon pail.

Page 7

7

Specifications

 

Power Supply

Dedicated 115VAC, 60 Hz, 15A.

 

 

 

 

 

 

Gas Supply Pipe

Minimum 1/2” NPT (schedule 40 black iron pipe recommended).

 

 

 

 

 

 

Approved Gas Type

Natural Gas.

 

 

 

 

 

 

Gas Pressure

6.0” W.C. minimum, 11.0” W.C. maximum.

 

 

 

 

 

 

Venting System

Power vent through the wall or vertical through the roof.

 

 

 

 

 

 

Approved Vent Materials

PVC, CPVC or ABS.

 

 

 

 

 

 

Minimum clearance for

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

 

 

Servicing

 

 

 

 

 

 

 

 

 

Water Supply Pressure

150 PSI maximum allowable working pressure. Check local codes for

 

 

supply pressure.

 

 

 

 

 

 

 

 

 

TCO Limit

Residential 118oF (87oC), Commercial 199oF (93oC).

 

 

 

 

 

 

Residential Temperature

60oF (16oC) to 160oF (71oC) (approximate temperatures).

 

 

Set Point Range

 

 

 

Commercial Tempera-

80oF (27oC) to 180oF (82oC) (approximate temperatures).

 

 

ture Set Point Range

 

 

 

 

 

 

 

 

 

Blower Temperature

Normally closed, opens @ 165oF (74oC), auto reset @130oF (54oC)

 

 

Switch

 

 

 

 

 

 

 

 

 

 

UTW1 Models:

 

 

 

Normally open, closes on vacuum increase @ -0.68,opens on vacuum

 

 

 

decrease @ -0.65

 

 

 

U4TW Models:

 

 

Pressure Switch

Normally open, closes on vacuum increase @ -0.83,opens on vacuum

 

 

 

 

 

 

decrease @ -0.80

 

 

 

U2TW & UTW4 Models:

 

 

 

Normally open, closes on vacuum increase @ -1.28,opens on vacuum

 

 

 

decrease @-1.25

 

 

 

 

 

 

 

U1TW & U4TW Models:

 

 

Blower

115VAC, 60Hz, 3.1 amps, 3000 RPM, 42 CFM @ 1.5” W.C.

 

 

U2TW & UTW4 Models:

 

 

 

 

 

 

115VAC, 60Hz, 3.1 amps, 3000 RPM, 68 CFM @ 0.4” W.C.

 

 

 

 

 

Page 8

8

Specifications

Vent Tables

Venting Specifications for:

40 Gallon

50 Gallon

60 Gallon

2” Diameter (5.1 cm) PVC Vent Connector Lengths

Terminating

# of Elbows

Maximum Straight

Minimum Straight

Length ft (m)

Length ft (m)

 

 

 

 

 

 

Through the Wall

1

45 (13.7)

2 (0.6)

 

 

 

 

Through the Wall

2

40 (12.2)

2 (0.6)

 

 

 

 

Through the Wall

3

35 (10.7)

2 (0.6)

 

 

 

 

Through the Wall

4

30 (9.2)

2 (0.6)

 

 

 

 

 

 

 

 

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

# of Elbows

Maximum Straight

Minimum Straight

Length ft (m)

Length ft (m)

 

 

 

 

 

 

Through the Wall

1

115 (35.0)

10 (3.1)

 

 

 

 

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)

15 (4.6)

 

 

 

 

Page 9

9

Specifications

Vent Tables

Venting Specifications for:

48 Gallon

65 Gallon

3” Diameter (7.6 cm) PVC Vent Connector Lengths

Terminating

# of Elbows

Maximum Straight

Minimum Straight

Length ft (m)

Length ft (m)

 

 

 

 

 

 

Through the Wall

1

55 (16.8)

2 (0.6)

 

 

 

 

Through the Wall

2

50 (15.2)

2 (0.6)

 

 

 

 

Through the Wall

3

45 (13.7)

2 (0.6)

 

 

 

 

Through the Wall

4

40 (12.2)

2 (0.6)

 

 

 

 

 

 

 

 

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

# of Elbows

Maximum Straight

Minimum Straight

Length ft (m)

Length ft (m)

 

 

 

 

 

 

Through the Wall

1

175 (53.3)

10 (3.1)

 

 

 

 

Through the Wall

2

170 (51.8)

10 (3.1)

 

 

 

 

Through the Wall

3

165 (50.3)

10 (3.1)

 

 

 

 

Through the Wall

4

160 (48.8)

10 (3.1)

 

 

 

 

Through the Wall

5

155 (47.2)

10 (3.1)

 

 

 

 

 

 

 

 

Through the Roof

0

180 (54.9)

15 (4.6)

 

 

 

 

Through the Roof

1

175 (53.3)

15 (4.6)

 

 

 

 

Through the Roof

2

170 (51.8)

15 (4.6)

 

 

 

 

Through the Roof

3

165 (50.3)

15 (4.6)

 

 

 

 

Through the Roof

4

160 (48.8)

15 (4.6)

 

 

 

 

Page 10

10

Specifications

 

Control Timings

 

 

Ignition State

Timing

 

 

Pre-purge

15 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 34 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)

 

 

Wiring Diagram

BLOWER

 

 

 

BLOWER

 

 

BLOWER

TEMPERATURE

 

 

MOTOR

SWITCH

 

 

 

 

 

 

M

PRESSURE

G

 

 

 

 

BL

SWITCH W

 

Y

 

 

 

W

 

R

BK

 

Y

 

G

 

 

 

 

 

PILOT

 

 

 

W

Honeywell

 

PLUG

 

BKBK

 

BK

G W

Y

 

R

 

BK BL

WATER TEMPERATURE

 

SENSOR

RESETTABLE

FLAMMABLE

 

THERMAL

VAPOR SENSOR

 

Page 11

11

Sequence of Operation

Power Up Sequence

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

2.Flammable Vapor Verification: The gas control verifies that the Flammable Vapor Sensor is in the proper operating range prior to energizing any components. If the sensor is within the proper range, the gas control resumes normal operation. If the Flammable Vapor Sensor is out of range, the gas control LED immediately flashes 7 times with a 3 second pause.

Normal Heating Sequence

1.Thermostat Calls for Heat: Prior to energizing the blower, the gas control checks the safety circuit to insure the circuit is open. In the safety circuit the pressure switch is normally open and the blower temperature switch is normally closed.

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

3.Blower energizes.

4.Pressure switch proves blower/vent system operation: If the pressure switch does not close within 30 seconds, the gas control LED flashes 3 times with 3 second pause. 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.

5.Blower pre-purgeperiod (15 seconds).

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

Page 12

12

Sequence of Operation

Normal Heating Sequence (cont’d)

7.Main Burner Ignition: After pilot flame is sensed, the gas control activates the main valve for main burner ignition. The gas control will ignore flame and pressure switch signals for 3 seconds to allow for the main burner to stabilize.

8.Steady State Operation: During steady state operation, the gas control monitors:

Thermostat Temperature Sensor: When the setpoint temperature is satisfied, the gas control is shutdown, and the blower will post-purgefor 15 seconds. The gas control LED flashes a short flash once every 4 seconds (Idle status code).

Pressure switch/blower temperature switch: If either switch opens, the pilot valve and the main valve are shut down. The blower continues to run for 30 seconds attempting to close the circuit. The gas control LED flashes 3 times with 3 second pause.

Flame Sensor: If flame is lost, the pilot and main valves are shutdown. The blower runs for 15 seconds. The gas control attempts to re-lightthe pilot 4 times. If unsuccessful, the blower is shutdown, and the gas control proceeds to a 5 minute lockout. The gas controlre-attemptsto light the pilot starting at Normal Heating Sequence #2.

9.Thermostat Satisfies: Gas control LED flashes once every 4 seconds. 10.Burner Off.

11.Blower post-purge(15 seconds).

Abnormal Operation

1.Flammable Vapor Sensor Fault:

A)If the resistance is greater than 70,000 ohms: The gas control immediately turns off all outputs. The gas 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 1 time 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.

Page 13

13

Sequence of Operation

Abnormal Operation (cont’d)

B)If the resistance is below 3000 ohms: The gas control immediately turns off all outputs and proceeds to flash 8 times then 1 time with a 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 Open Circuit: The gas control immediately turns off all outputs and proceeds to flash 8 times then 3 times with a 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 3 times with three second pause. The error self clears if the fault clears for at least 15 seconds.

C)Water Temperature in excess of ECO (Energy Cut Off) Limit: The gas control immediately turns off the pilot and main valves. The gas control LED proceeds to flash 4 times with a 3 second pause.

To reset the gas control, rotate the setpoint knob to the minimum setting for at least 6 seconds before returning to desired temperature setting.

3.Pressure Switch/Blower Temperature Fault:

A)Pressure switch closed at start of call for heat: The gas control waits 4 seconds then, proceeds to flash 2 times with a 3 second pause. The gas control waits 2 minutes and then turns on the blower for 30 seconds. The blower turns off after 30 seconds and the control waits for the pressure switch to open. Any time the pressure switch opens, the blower turns on (or stays on) and the control proceeds to wait for the pressure switch to close.

Page 14

14

Sequence of Operation

Abnormal Operation (cont’d)

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 the 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 a 3 second pause. The gas control waits 2 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 operation: The gas control turns off the pilot and main valve, runs the blower for 15 seconds (inter-purge)waiting for the pressure switch and/or the blower temperature switch to close. If either switch fails to close, the gas control proceeds as described in 3b above. If the circuit closes again by the end of theinter-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 a 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 the 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 a 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 spark igniter turns off, the pilot valve is closed. The gas control LED flashes 6 times then 1 time with 3 second pause. The control waits 5 minutes before repeating the ignition sequence.

Page 15

15

Sequence of Operation

Abnormal Operation (cont’d)

5.Flame Sensing Fault:

A)Flame Lost During Run: The gas control turns off the pilot and main valves and runs the 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 LED flashes 6 times then 3 times with a 3 second pause. The gas control waits 5 minutes before repeating the ignition sequence.

B)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 a 3 second pause. The control waits 5 minutes before repeating the ignition sequence.

Page 16

16

Troubleshooting

Observe the green LED on the water heater gas control. Error codes are displayed with a 3 second pause before repeating. Once the error code is known, check and repair the water heater, as recommended in the table below.

Green LED

LED Status

Control Status

 

Probable Cause

Service Procedure

None (LED

 

Control power switch in "OFF"

 

not on or

No electrical power

position.

Turn Power On

flashing)

 

Supply voltage interrupted.

 

One short

Stand-bymode,

Temperature demand is satisfied

 

flash every

Thermostat is

Normal operation

four seconds

satisfied (no faults)

(no call for heat)

 

Alternates

 

 

 

 

bright and

Thermostat calling

Tank temperature below

Normal operation

dim

for heat (no fault)

setpoint of thermostat

 

(heartbeat)

 

 

 

 

 

 

1.

Unstable pilot

 

 

 

2.

Pilot tube blocked or restricted

1. See Burner Inspection on

Short flash

Weak pilot signal

3.

Oxidation build-upon pilot

page 20

once every

electrode

2-4.See Pilot Inspection,

second

on last call for heat

4.

Wire damage to pilot

Testing and Replacement on

 

 

assembly or bad connection at

page 22

 

 

gas control

 

 

 

 

 

 

 

 

1.

Pressure switch tubing kinked

 

Two flashes,

Pressure switch not

or blocked

1-3.See Pressure Switch

three second

working-closed

2.

Blocked pressure tap on

Testing on page 25

pause

position

switch or blower

 

 

 

3.

Faulty pressure switch

 

 

 

1.

Vent blockage or improper

 

 

 

vent configuration

 

 

 

2.

Pressure switch tubing kinked

1. Check vent or vent tables

Three

Pressure switch or

or blocked

2-3.See Pressure Switch

flashes,

blower temperature

3.

Faulty pressure switch

Testing on page 25

three second

switch not working-

4.

Blower not spinning up to

4. See Blower Testing on

pause

open position

speed

page 28

5.

Blower temperature or

5-6.See blower Temperature

 

 

 

 

exhaust temperature too high

Switch Testing on page 31

 

 

6.

Faulty blower temperature

 

 

 

switch

 

Four flashes,

Excessive tank

1.

Thermal well sensor out of

1. Test Gas Control & Thermal

temperature,

Well

three second

calibration

system must be

2. Replace gas control if

pause

2.

Faulty gas control

reset

necessary

 

 

 

Five flashes,

False pilot flame

 

 

 

three second

Pilot valve stuck in open position

Replace gas control

present

pause

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Page 17

17

Troubleshooting

 

LED Status

Control Status

 

Probable Cause

Service Procedure

 

 

 

 

 

1. Unstable pilot

 

 

 

Six flashes,

 

2. Pilot tube block or restricted

1. See Burner Inspection

 

 

one flash,

Failed to light pilot,

 

3. Oxidation build-upon pilot

on page 20

 

 

three second

system resets after

 

electrode

2-4.See Pilot Inspection,

 

 

pause (Soft

(5) minutes

 

4. Wire damage to pilot

Testing and Replacement

 

 

Lockout)

 

assembly or bad connection at

on page 22

 

 

 

 

 

gas valve

 

 

 

 

 

 

 

 

 

 

 

 

1.

Vent blockage or improper

 

 

 

 

 

vent configuration

1. Check vent or vent

 

 

 

 

2.

Pressure switch tubing kinked

tables

 

 

 

Pressure switch or

or blocked

2-3.See Pressure Switch

 

 

Six flashes,

blower temperature

3.

Faulty pressure switch

Testing on page 25

 

 

two flashes,

switch opened

4.

Vent termination being

4. Refer to venting section

 

 

three second

during burner

affected by wind

of installation manual

 

 

pause (Soft

operation. System

5.

Blower not spinning up to

5. See Blower Testing on

 

 

Lockout)

resets after (5)

speed

page 28

 

 

 

minutes

6.

Blower temperature or

6-7.See Blower

 

 

 

 

exhaust temperature too high

Temperature Switch

 

 

 

 

7.

Faulty blower temperature

Testing on page 31

 

 

 

 

switch

 

 

 

 

 

1.

Unstable pilot

 

 

 

Six flashes,

 

2.

Pilot tube block or restricted

1. See Burner Inspection

 

 

 

3.

Oxidation build-upon pilot

on page 20

 

 

three

Pilot flame

 

 

electrode

2-4.See Pilot Inspection,

 

 

flashes,

extinguished,

 

 

4.

Wire damage to pilot

Testing and Replacement

 

 

three second

system auto resets

 

 

pause (Soft

after (5) minutes

assembly or bad connection at

on page 22

 

 

gas control

5. Refer to Installation &

 

 

Lockout)

 

 

 

 

5.

Insufficient combustion air

Operation Manual

 

 

 

 

 

 

 

 

6.

Insufficient gas pressure

 

 

 

Six flashes,

Undesired false

 

 

 

 

 

four flashes,

 

 

 

 

 

pilot flame sensed,

Pilot valve stuck in open position

Replace gas control

 

 

three second

 

 

pause

system auto resets

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1.

Flammable vapor present

 

 

 

 

Flammable vapor

2.

Flammable vapor sensor

 

 

 

Seven

sensor or

exposed to excessive moisture

 

 

 

flashes,

resettable thermal

3.

Flammable vapor sensor

See Flammable Vapor

 

 

three second

switch fault

exposed to extreme ambient

Sensor Testing on page 40

 

 

pause

detected, see

temperature

 

 

 

 

warning label

4.

Resettable thermal switch

 

 

 

 

 

open

 

 

 

 

 

1.

Flammable vapor sensor out

 

 

 

Eight

Flammable vapor

of specification; verify Flammable

 

 

 

flashes, one

Vapor Sensor (FVS) resistance is

 

 

 

sensor out of

See Flammable Vapor

 

 

flash, three

specification,

not below 25 k .

Sensor Testing on page 40

 

 

second

2.

Possible short in flammable

 

 

possible short

 

 

 

pause

vapor sensor or resettable

 

 

 

 

 

 

 

 

 

thermal switch wiring

 

 

 

 

 

 

 

 

 

Page 18

18

 

 

 

 

 

Troubleshooting

 

 

 

 

 

 

 

 

 

LED Status

Control Status

 

Probable Cause

 

Service Procedure

 

 

 

 

 

 

 

 

 

 

 

 

1.

Damage to thermal well wires

 

 

 

 

 

 

2.

Thermal well sensor resistance

 

 

 

 

Eight flashes,

Thermal well sensor

out of range

 

 

 

 

three flashes,

damaged or un-

3.

Replace thermal well

 

See Thermal Well Testing on

 

 

plugged or gas con-

4.

Verify control is not wet or

 

 

 

three second

trol electronics fault

physically damaged

 

page 34

 

 

pause

detected

5.

Reset control on/off switch

 

 

 

 

 

 

 

 

 

 

 

6.

Replace gas control if 8-3error

 

 

 

 

 

 

persists

 

 

 

 

 

 

 

 

 

 

 

 

Eight flashes,

 

1.

Verify control is not wet or

 

1. Replace gas control if wet

 

 

 

physically damaged

 

 

 

four flashes,

Gas control fault

 

or physically damaged

 

 

2.

Reset control on/off switch

 

 

 

three second

detected

 

2. Cycle power

 

 

3.

Replace gas control if 8-4error

 

 

 

pause

 

 

3. Replace gas control

 

 

 

 

persists

 

 

 

 

 

 

 

 

 

 

 

Page 19

19

Burner Maintenance

Burner Inspection

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. The pilot flame should be stable. Some causes for an unstable pilot flame are:

a)Gas pressure is out of specification.

b)Pilot flame not fully engulfing spark/flame sensor.

The main burner should light smoothly from the pilot and burn with a blue flame with a minimum of yellow tips. After 5 minutes of operation the burner screen will become radiant and the flame will soften and turn orange. If the burner screen does not become radiant after 5 minutes of operation it must be cleaned (see burner cleaning procedure below).

Burner Cleaning Procedure

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

Gas control power switch

Step 2. Unplug the water heater from the wall outlet.

TTW (water heater) power cord

Step 3.

Turn off the gas supply to the water

heater.

 

Step 4.

Remove the outer door.

 

Outer door

Page 20

 

20

screws
(2) 1/4” hex drive

Burner Maintenance

Burner Cleaning Procedure (cont’d)

Step 5. Remove the (4) 1/4” hex drive screws holding the right side inner door in place.

(4) 1/4” hex drive screws

Step 6. Remove the (3) 1/4” hex drive screws holding the left side burner door in place.

(3) 1/4” hex drive screws

Step 7. Disconnect the pilot tube using a 7/16” wrench and the main burner feedline with a 3/4” wrench from the gas control.

Pilot and main feedlines

Step 8. Disconnect the spark igniter/flame sensor

wire from gas control.

Gas control

Spark igniter/flame sensor wire

Right side inner door

Left side burner door

Step 9. Remove the burner assembly from the combustion chamber.

Burner assembly

Step 10. Remove manifold mount from burner inner door

by removing (2) 1/4” hex drive screws.

Page 21

21

Burner screen

Pilot Maintenance

Burner Cleaning Procedure (cont’d)

Step 11. Thoroughly inspect burner screen and burner venturi and remove any loose debris accumulation. Inspect burner screen for any openings larger than the normal screen openings.

Step 12. Use compressed air and/or a vacuum to remove any scale or other debris accumulation from the burner screen and venturi.

Burner venturi

Step 13. Disconnect (unscrew) manifold mount from feed line. Use a stiff brush, compressed air and/or vacuum to remove any debris build up from the manifold

mount.

Manifold mount

Feedline

Step 14. Remove main burner orifice from feed line (3/8” wrench). Inspect and clean if necessary.

Main burner orifice

Step 15. Reassemble the burner assembly and reinstall into the water heater. Restore gas supply and check for gas leaks.

Step 16. To resume operation, follow the instructions located on the water heater lighting instruction label. Or, use the lighting instructions located in the water heater installation and operating manual.

Pilot Inspection, Testing and Replacement

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

Gas control power switch

Page 22

22

Pilot Maintenance

Pilot Inspection, Testing and Replacement (cont’d)

Step 2.

Unplug the water heater

TTW (water heater)

from the wall outlet.

power cord

Step 3.

Turn off the gas supply to the water heater.

Step 4.

Remove the outer door.

Outer Door

Step 5. Remove the (4) 1/4” hex drive screws holding the right side inner door in place.

(4) 1/4” hex drive screws

Step 6. Disconnect the pilot tube using a 7/16” wrench and the main burner feedline with a 3/4” wrench from the gas control.

 

 

Pilot and main

 

 

feedlines

Step 7.

Disconnect the spark igniter/flame sensor

wire from gas control.

Gas control

Spark igniter/flame sensor wire

Right side inner door

Page 23

23

Step 14. Visually inspect the pilot tubing for kinks or cracks. is found, replace the pilot assembly.
Page 24
If damage
1/4” nut driver
Step 10. Visually inspect the spark igniter/flame sense wire for damage. Replace the pilot assembly, if damage is found.
Step 11. With a multi-meter set to the ohms setting, check continuity through the spark igniter/flame sense wire. Replace the pilot, if there is no continuity.
Multi-meter
Step 12. Visually inspect the spark igniter/flame sense electrode for deterioration. Replace the pilot assembly, if necessary. The electrode should not be in contact with pilot hood. If it is in contact with the pilot hood, carefully adjust electrode to a gap distance of 3/32" from the pilot hood.
Step 13. Visually inspect the spark igniter/flame sense electrode for oxidation build up. Carefully clean any oxidation using very fine emery cloth.
Step 9. Remove the pilot assembly from the
feedline using a 1/4" nut driver.
Pilot assembly
main
Pilot Maintenance
Pilot Inspection, Testing and Replacement (cont’d)
Step 8. Remove the burner assembly from the combustion chamber.
Burner assembly

24

Gas control power switch

Pressure Switch Testing

Pilot Inspection, Testing and Replacement (cont’d)

Step 15. Inspect the pilot tubing and pilot orifice for blockages:

a) Remove ferrule nut from the bottom of the pilot assembly using a 7/16" wrench.

b) Remove the pilot tube and pilot orifice.

c) Inspect the pilot tubing and pilot orifice for blockages. Clean or replace, as necessary.

Step 16. Reassemble the pilot assembly and install it on the main burner. Reinstall the burner assembly into the combustion chamber. Restore the gas supply and check for gas leaks.

Step 17. To resume operation, follow the instructions located on the water heater lighting instruction label. Or, use the lighting instructions located in the water heater installation and operating manual.

Pressure Switch Testing

WARNING

115 volt potential exposure. Use caution making voltage checks to avoid personal injury.

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

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

cover (see photo 1).

Step 3. Carefully remove pres-

sure switch from blower housing (see photo 2).

1

2

Pressure Switch

Page 25

25

Pressure Switch Testing

Pressure Switch Testing (cont’d)

Pressure switch

wire leads

With steps 1,2 & 3 complete, disconnect wire leads from pressure switch.

Use a multi-meterset to the ohms setting. With blower off, check across the pressure switch terminals. Are the switch contacts open (no electrical continuity)?

Y

Position the gas control power switch to the “ON” position and adjust the thermostat to call for heat. This will start the blower. Check with the multi-meter.Do the pressure switch contacts close with the blower running?

Y

The switch contacts are OK. See safety circuit trace (page 40).

Page 26

N

Check the tubing and

N

pressure tap on switch

Replace switch

 

 

for blockage. Is there

(see page 27).

 

a blockage?

 

 

Y

Clear blockage

 

 

 

 

 

 

 

 

Y

 

Check the tub-

 

 

 

N ing and pressureN

Is the vent

 

tap on switch for

system

 

blockage. Is

blocked?

 

there a block-

 

 

age?

N

 

 

 

 

 

 

 

Y

 

 

Is vent system

 

 

 

length within the Y

See blower

 

 

vent table specifi-

testing (page

 

 

cations listed on

28). Is the

 

 

pages 9 & 10?

Blower OK?

 

 

N

N

 

 

 

 

 

Reconfigure vent

Correct the

 

 

system to be

blower prob-

 

 

compliant with

lem.

 

 

vent tables.

 

26

Pressure Switch Replacement

Pressure Switch Replacement

WARNING

115 volt potential exposure. Use caution making voltage checks to avoid personal injury.

Step 1. Move the gas control power switch to the

“OFF” position.

Gas control power switch

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

Control access cover

Step 3. Carefully remove pressure switch from blower housing.

Control access cover

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

Step 4. Disconnect tubing from the pressure switch.

Pressure switch tubing

Page 27

27

Blower Testing

Step 5. Disconnect yellow wires from the pres-

sure switch.

Yellow pressure switch wires

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 the “ON” postion and verify proper heater operation.

Step 10. Replace control access cover form step 2.

Blower Testing

WARNING

115 volt potential exposure. Use caution making voltage checks to avoid personal injury.

Step 1. Move the gas control power switch to the “ON” position and adjust control to call for heat.

Gas control power switch

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

Control access cover

Page 28

28

29

in jacket head
Pin location holes
blower flange
Locating pins on

Blower Replacement

Blower Removal

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

Gas control power switch

Step 2. Unplug the water heater from the wall outlet.

 

 

TTW (water heater)

 

 

power cord

Step 3.

Disconnect vent

system

 

from exhaust adapter on top of blower.

Remove exhaust

adapter and retain

 

 

 

 

 

 

for use on new

Step 4.

Remove exhaust

adapter

blower

 

from blower (blade screw driver) and retain for use on new blower.

Step 5. Remove dilution air clip from air intake boot and retain for use on new blower.

Step 6.

Unplug cord sets from blower.

Blower cord

 

 

Step 7.

Remove the three blower

sets

mounting screws (1/4” nut driver).

 

Step 8. Remove blower with gasket from water heater.

Blower Installation

Step 9. Clean any debris from jacket head of water heater

Step 10. 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.

Page 30

Blower mounting screws

Remove dilution air clip and retain for use on new blower

30

Blower Temperature Switch Testing

Blower Installation (cont’d)

Step 11. Secure blower in place using mounting screws from step 7. Step 12. Reinstall exhaust adapter from step 4.

Step 13. Reinstall dilution air clip from step 5.

Step 14. Reconnect vent system to exhaust adapter.

Step 15. Reconnect cords from step 6.

Step 16. Position gas control power switch to the “ON” position. Step 17. Verify proper blower operation.

Blower Temperature Switch Testing

WARNING

115 volt potential exposure. Use caution making voltage checks to avoid personal injury.

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

Gas control power switch

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

cover.

Control access cover

Blower temperature

switch location

Step 3. Locate the blower temperature switch.

Air mixing inlet

Page 31

31

Blower Temperature Switch Testing

Blower Temperature Switch Testing (cont’d)

Switch Setting

Opens on rise @ approximately 165oF

Auto resets on fall @ approximately 160oF

Cool switch to below 160oF

Disconnect wire leads to

switch. Using multi-metersetN

Replace switch

to the ohms setting. Is there

(see page 33).

continuity between the switch terminals?

Y

 

 

 

 

 

 

N

 

 

Reconnect wire leads and ob-

Y

 

 

 

serve heater operation. Do

Do switch

Y

Exhaust

 

exhaust gas temperatures

 

contacts

 

temperature

rise to or above 170oF with

 

open?

 

is too hot.

vent connected?

 

 

 

 

N

 

 

 

 

Y

Replace switch

 

 

Do switch con-

 

 

tacts open?

 

(see page 33).

 

 

N

Switch OK

Page 32

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

32

blower housing
Snip retaining lug from

Blower Temperature Switch Replacement

Blower Temperature Switch Replacement

WARNING

115 volt potential exposure. Use caution making voltage checks to avoid personal injury.

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

Gas control power switch

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

sembly and remove cover.

Control access cover

Step 3. Locate blower temperature switch.

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

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

blower housing to allow removal of temperature switch.

Step 6. Remove switch from blower housing.

Blower temperature switch location

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

Step 8. Reconnect red and yellow wires to new switch. Wires are interchangeable with either terminal.

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

Step 10. Replace control access cover from step 2.

Page 33

33

Thermal Well Testing

Thermal Well Testing

CAUTION

Do not use standard multi-meterprobes for this testing. Doing so will damage the connector. Use special pin type electronic probes or small diameter wire pins inserted into connector.

Follow the procedure, below, if the water heater gas control has gone into a ECO lockout (4 flash, 3 second pause). Reset the gas control by rotating the setpoint knob to the minimum setting for at least 6 seconds before returning to the desired water temperature setting.

Step 1. Unplug the thermal well connector from the gas

control.

Thermal well connector

Step 2. With a multi-meterset to the ohms setting, measure the resistance between the middle and right side wires.

Step 3. With a multi-meterset to the ohms setting, measure the resistance between the middle and left side wires.

Page 34

34

Determine Tank Temperature

Thermal Well Testing (cont’d)

Determine the correct resistance values using the Determine the Water Temperature Inside the Tank procedure on page 23. If the values are correct, replace the gas control, otherwise replace the thermal well.

Determine Water Temperature Inside Tank

WARNING

Stored water may be HOT when performing the following steps in this procedure. Take necessary precaution to prevent personal injury.

Note: It is important to understand once the resistance for the thermal well is determined using the Thermal Well Testing Procedure on page 21, water flow through the water 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. Move the gas control power switch to the “OFF”

position.

Gas control power switch

Step 2. Draw approximately 4 gallons of water from the drain valve into a container and discard. Draw an additional gallon and immediately measure the 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 on page 23, determine the 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.

Page 35

35

Component Disassembly

Sensor Resistance at Various Temperatures

In Degrees F

 

 

 

 

 

 

 

 

 

 

 

°F

0

1

2

3

4

5

6

7

8

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

10000

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

 

 

 

 

 

 

 

 

 

 

 

Gas Control & Thermal Well Removal From Water Heater

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

Gas control power switch

Step 2. Unplug the water heater from the wall outlet.

TTW (water heater) power cord

Step 3. Drain the water heater to a point below the gas control level.

Step 4. Turn off the gas supply to the water heater and disconnect the gas piping from the gas control.

Page 36

36

Unplug the water heater from the wall outlet.
TTW (water heater) power cord
Step 2.
Move the gas control power switch to the “OFF”
Gas control power switch
Step 1. position.
Gas Control & Thermal Well Removal From Water Heater (cont’d)
Step 4. Disconnect the pilot tube using a 7/16” wrench and the main burner feedline with a 3/4” wrench from the gas control.
Pilot and main feedlines
Step 5. Disconnect the wire harnesses and spark igniter/ flame sense wire from the gas control.
Gas control
Spark igniter/flame sensor wire
Step 6. Remove the gas control & thermal well by rotating the flats of the Thermal Well counter clockwise using a 1-5/16”
wrench. Flats of thermal well
Gas Control Removal From Thermal Well
Following the steps below allows for the removal of the gas control from the thermal well without removing the thermal well from the tank.

Gas Control Removal

Page 37

37

Gas Control Assembly

Gas Control Removal From Thermal Well (cont’d)

Step 3. Turn off the gas supply to the water heater and disconnect the gas piping from the gas control.

Step 4. Disconnect the pilot tube using a 7/16” wrench and the main burner feedline with a 3/4” wrench from the gas control.

Pilot and main feedlines

Step 5. Disconnect the wire harnesses and spark igniter/

flame sense wire from the gas control.

Gas control

Spark igniter/flame sensor wire

Step 6. Using the gas control service tool, p/n 239-45991-00, available from your BWC parts supplier, insert the tool into the back of the gas control.

Gas control service tool

Step 7. Pivot the tool towards the water heater, as far as possible. Lift straight up on the gas control. The gas control should move about 1/8". Hold the gas control in position and remove the tool. Lift straight up on the gas control to remove it completely from the thermal well.

Gas Control Assembly to the Thermal Well

Step 1. Install the threaded end of the thermal well into the tank. Be sure the thermal well flange is positioned properly to allow for proper gas control installation. Tighten the thermal well using a 1-5/16”wrench.

Page 38

38

Gas Control Assembly

Gas Control Assembly to the Thermal Well (cont’d)

Step 2. Route the wire leads back into relief opening.

Wire leads on thermal well

Slots in thermal well

Relief opening

Step 3. Align the slots located on the thermal well flange with the tabs located on the back of the gas control.

Tabs on back of gas control

Step 4. Carefully push the gas control back onto the thermal well flange as far as possible towards the water heater. Then, slide the gas control down to lock into position.

Step 5. Install the burner assembly and connect the pilot and main feedlines to the gas control using a 7/16” and 3/4” wrench, respectively.

Pilot and main feedlines

Step 6. Reconnect the wire harnesses to the gas control.

Wire harnesses

Step 7. Reconnect the gas piping to the gas control. Restore the gas supply and check for gas leaks.

Page 39

39

Step 2. With the water heater plugged in and the gas control power switch in the “ON” position verify LED status.
Page 40
Verify 115VAC and proper polarity are at the wall outlet.
Step 1.
sensor harness
Step 3. Using a multi-meter set to the ohms setting, measure the resistance of the flammable vapor sensor and resettable thermal switch. The resistance must be between 3,000 and 48,000 ohms. If the resistance is out of this range, verify that the resettable thermal switch has not been tripped. If it hasn’t, replace
the thermal switch.
Flammable vapor sensor harness
115 VAC Circuit Trace
Flammable vapor
Step 2. Disconnect from the gas control.
Step 1. position.

Flammable Vapor Sensor Testing

Gas Control Assembly to the Thermal Well (cont’d)

Step 8. To resume operation, follow the instructions located on the water heater lighting instruction label. Or, use the lighting instructions located in the water heater installation and operating manual.

Flammable Vapor Sensor Testing

CAUTION

Do not use standard multi-meterprobes for this testing. Doing so will damage the connector. Use special pin type electronic probes or small diameter wire pins inserted into connector.

Move the gas control power switch to the “OFF”

Gas control power switch

the flammable vapor sensor harness

40

115 VAC Circuit Trace

WARNING

115 volt potential exposure. Use caution making voltage checks to avoid personal injury.

LED status: None, control LED not on or flashing.

Disconnect cord set as shown in photo 9.

Using a volt meter set to volts AC, is there 115VAC across terminals shown in photo 10?

Y

Is there 115VAC across terminals shown in photo 11?

N

Incorrect supply voltage polarity.

LED status:

LED status:

Short flash

“Heartbeat”,

once every four

alternates

seconds.

bright/dim.

Waiting for call

Thermostat call-

for heat.

ing for heat.

9

10

N

 

 

Check for damage

Y

 

 

 

 

 

to AC supply

 

N

 

power cord.

 

Reconnect cord set

 

 

shown in photo 9.

N

 

Replace blower. Disconnect wire har-

ness from gas control (see photo 12).

Wire harness

LED status: Various flashing error codes.

Verify error code as listed on page 17.

11

Repair damage.

12

Locate black & white wires at connector, it may be necessary to pull back wire sheath to identify wire colors (see photo 13).

Is there 115VAC across

Y

Replace gas control.

black & white wire as

 

shown in photo 13?

 

N

 

Call for technical support.

 

13

Wire sheath pulled back to identify wire colors

Check for 115VAC between black and white wires.

-NOTE-

Electronic meter probes required. Use car not to damage connector during this check.

Page 41

41

Control access cover

Safety Circuit Voltage Trace

WARNING

115 volt potential exposure. Use caution making voltage checks to avoid personal injury.

Safety Circuit Voltage Trace

14

Note: This procedure assumes a cold tank.

Step 1. Remove three screws (Phillips screw driver) from control access cover on blower and remove

cover.

Position gas control switch to the “ON” position and adjust the thermostat dial to call for heat. Is there 10 to 13VAC between the red wire leading to the blower temperature switch and the green ground wire? Blower must be running during this voltage check (see photo 15).

Y

Is there 10 to 13VAC between

the yellow wire leading from the N pressure switch and the green ground wire (see photo 27)?

Y

N

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 control and refer to troubleshooting section on page 17.

NIs LED on gas valve flash-

ing the “heartbeat” code (alternating bright/dim)?

N

Verify 115VAC to gas control (see page 41).

N

Y

No voltage from gas control. Call for technical support.

Determine cause of blower temperature switch activa-

tion and correct.

Is there continuity through the blower temperature

switch (see page 31)?

Check igniter/sensor (see page 22). Is igniter/sensor OK?

Correct igniter/ sensor problem

Green ground wire

Red sire leading to blower temp. switch

Yellow wire leading from pressure switch

YCheck for loose or broken

wire connection at switch terminals.

Y

Faulty cord set or gas control

15

Page 42

42

Blower Removal

Remove the Blower to Gain Access to the Flue Baffle

Step 1. Move the gas control Gas control power p o w e r

switch

switch to the “OFF” position.

 

 

TTW (water heater)

 

Step 2.

Unplug the water

power cord

heater

 

from the wall outlet.

Exhaust adapter

Blower mounting screws

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

Step 4. Unplug the cord sets from the

blower.

Blower cord sets

Step 5. Remove the three blower mounting screws (1/4” nut driver).

Step 6. Remove the blower with gasket from the top of the water heater.

Step 7. Remove the flue baffle from the

Flue baffle

Page 43

43

Dip Tube Inspection

water heater.

Remove the Blower to Gain Access to the Flue Baffle (cont’d)

Step 8. Inspect the baffle for deterioration and missing restrictors. Clean any scale or debris build-up.Replace with a new baffle, as necessary.

Step 9. Reinstall the baffle into the flue. Be sure the baffle hanger tab is inserted into the notch locations at the top of the flue.

Step 10. Check the burner to ensure no scale has accumulated during operation. See the Burner Cleaning Procedure on page 20, if accumulation has occurred.

Step 11. Secure the blower in place using the screws from Step 5.

Step 12. Reconnect the vent system to the exhaust adapter.

Step 13. Reconnect the cord sets from Step 4.

Step 14. Plug the water heater into the wall outlet.

Step 15. To resume operation, follow the instructions located on the water heater

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.

lighting instruction label. Or, use the lighting instructions located in the water heater installation and operating manual.

Dip Tube Inspection and Replacement

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

Step 2. Unplug the water heater from the wall outlet.

Step 3. Turn off the cold water supply to the water heater. Connect a hose to the drain valve of the water heater and route to an open drain. Open a nearby hot water faucet to vent the water heater for draining. Open the drain valve of water heater and allow the water heater to drain to a point below the inlet connection nipple.

Step 4. Disconnect the inlet nipple from the plumbing system.

Step 5. With an appropriate tool, such as a pipe wrench, remove the inlet nipple/ diptube from the water heater. Use caution not to damage pipe threads.

Step 6. Visually inspect the inlet nipple/diptube. The inlet nipple/diptube should

Page 44

44

Anode Inspection

be free of cracks and any blockage. Hydro-jetslots 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/diptube must be replaced.

Step 7. Upon completion of the inspection or subsequent replacement, reinstall the inlet nipple/diptube into the water heater. Connect the nipple to the plumbing system, resume water supply to the water heater, and refill the water heater.

Step 8. To resume operation, follow the instructions located on the water heater

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.

lighting instruction label. Or, use the lighting instructions located in the water heater installation and operating manual.

Anode Inspection and Replacement

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

Step 2. Unplug the water heater from the wall outlet.

Step 3. Turn off the cold water supply to the water heater. Connect a hose to the drain valve of the water heater and route to an open drain. Open a nearby hot water faucet to vent the water heater for draining. Open the drain valve of water heater and allow the water heater to drain to a point below the outlet connection nipple.

Step 4. Disconnect the outlet nipple from the plumbing system.

Step 5. With an appropriate tool, such as a pipe wrench, remove the outlet nipple/anode from the water heater. Use caution not to damage the pipe threads.

Step 6. Visually inspect the outlet nipple/anode. The outlet nipple/anode should show signs of depletion, which is normal. If depletion is one-halfthe original anode diameter (approximately 3/4” diameter), replacement is recommended. If any of the steel core of the anode is exposed, replacement is recommended.

Step 7. Upon completion of the inspection or subsequent replacement, reinstall the outlet nipple/anode into the water heater. Connect the nipple to the plumbing system, resume water supply to the water heater, and refill the water heater.

Page 45

45

Inner Door Removal

Step 8. To resume operation, follow the instructions located on the water heater lighting instruction label. Or, use the lighting instructions located

in the water heater installation and operating manual.

Inner Door Removal Procedure

Gas control power switch

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

Blower (water heater) power cord

Step 2. Unplug the water heater from the wall outlet.

Outer door

Step 3. Remove the outer door.

(4) 1/4” hex drive screws

Step 4. Remove (4) 1/4” hex drive screws from the right side inner door.

(3) 1/4” hex drive screws

Right side inner door

Step 5. Remove (3) 1/4” drive screws from the left side burner door.

Connectors attached to resettable thermal switch

Page 46

46

Inner Door Gasket Replacement

Step 6. Remove the connectors attached to the resettable thermal switch on the manifold mount.

Flammable vapor

sensor clip

Inner Door Removal Procedure (cont’d)

Step 7. Remove the flammable vapor sensor from the clip by pushing down on the tab to open the clip.

Flammable vapor sensor

Step 8. Inspect both inner doors for any of the following imperfections: tears, missing material, cracks, dirt or debris, lack of adhesion to the inner door, material left

WARNING

If the information in these instructions is not followed exactly, a fire or explosion may result causing property damage, personal injury, or death.

on combustion chamber, or any other imperfections that will inhibit a proper seal.

If any of the imperfections above are present,

door gasket following the Inner Door Gasket Gasket overlap must be

as shown ± 1/32

Replacement Procedure. If not, replacement of the inner door gaskets is not necessary.

Inner Door Gasket Replacement Procedure

Step 1. Completely remove all gasket and adhesive residue from the right and left side inner doors, as needed.

replace the inner

Enlarged view of flange area

Recommended pattern for RTV sealant Step 2.

U s i n g

 

RTV

sealant,

 

apply a 1/8”

 

bead to secure

 

Gasket overlap must be

 

Slice gasket here to slide over burner venturi t h e

as shown ± 1/32

Expanded view

Page 47

47

Inner Door Installation

inner door gasket to the inner door sections. Refer to the illustration for proper applica-

WARNING

Stripped fastener connections may allow for an inner door seal breach. A seal breach may result in a fire or explosion, causing property damage, personal injury, or death. Do not over tighten screws. If a fastener connection is stripped, contact the manufacturer listed on the water heater rating plate.

tion. Note the overlap configuration in the flange area of the inner door. Set the flange section first, and this will help to achieve the proper overlap position.

Inner Door Installation with Gasket

Step 1. Clean any residual gasket residue or other debris from the combustion chamber surface before installing the inner door/gasket assembly.

Step 2. Place the left side inner door into position first, being sure to firmly position the concave channel of the inner door around the feedline.

Step 3. Using the 1/4” hex drive screws removed in Step 5 of the Inner Door Removal Procedure on page 32, secure the left side inner door in place. Do not overtighten the screws.

Step 3. Position the pilot tube and spark igniter wire against the left side inner door flange gasket. Do not route these through the concave channel with the feedline.

Step 4. Firmly place the right side inner door flange against the left side inner door flange.

Step 5. Using the 1/4” hex drive screws removed in Step 4 of the Inner Door Removal Procedure on page 32, secure the two flanges together. Do not over-tightenthe screws.

Step 6. Align the right side inner door to the combustion chamber and verify the fastener holes of the combustion chamber are aligned with the right side inner door slotted openings. Verify seal integrity around the combustion chamber opening.

Step 7. Using the 1/4” hex drive screws removed in Step 3 of the Inner Door Removal Procedure on page 32, secure the right side inner door. Do not over-tightenthe

Page 48

48

Arrestor Cleaning

screws. Verify that both the left and right side inner doors are properly positioned and sealed against the combustion chamber.

Step 8. Re-installthe outer door.

Step 9. To resume operation, follow the instructions located on the water heater lighting instruction label. Or, use the lighting instructions located in the water heater installation and operating manual.

ScreenLok® Flame Arrestor Cleaning Procedure

Step 1. Move the gas control power switch to the “OFF” position and unplug the water heater from the wall outlet.

Step 2. Remove the outer door.

Step 3. Remove the right side inner door per the Inner Door Removal Procedure on page 32.

Step 4. Disconnect the pilot tube using a 7/16” wrench and the main burner feedline with a 3/4” wrench from the gas control.

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

Step 6. Remove the burner assembly from the combustion chamber.

Step 7. Clean the ScreenLok® flame arrestor using a stiff brush, compressed air, and/or a shop vacuum to remove any scale or other debris accumulation. Using a soft brush, clear jacket openings from any dirt, dust, restrictions, or other obstructions.

Step 8. Remove any debris from the burner assembly following the Burner Cleaning Procedure on page 15.

Step 9. Re-installthe burner assembly.

Step 10. Reconnect the main and pilot tubing and spark igniter wire to the gas control.

Step 11. Re-installthe inner door per the Inner Door Installation with Gasket Procedure on page 34.

Step 12. To resume operation, follow the instructions located on the water heater lighting instruction label. Or, use the lighting instructions located in the water heater installation and operating manual.

Page 49

49

Common Terms

Common Terms

BTU

British Thermal Units

ECO

Energy Cut Off

GPM

Gallons per Minute

Hz

Hertz

KWh

Kilowatts per hour

LED

Light Emitting Diode

NPT

National Pipe Thread

Ohms

Ohms of resistance

PSI

Pounds per Square Inch

RPM

Revolutions per Minute

VAC

Volts Alternating Current

W.C.

Inches of Water Column

°C

Degrees Centigrade

°F

Degrees Fahrenheit

NOTES

____________________________________________________________

____________________________________________________________

____________________________________________________________

Page 50

50

 

 

 

 

 

 

Parts List

 

 

 

 

 

2

 

 

 

 

 

 

 

 

 

40

 

 

 

9

12

3

 

 

 

 

 

 

 

 

 

 

 

10

13

 

 

1

 

 

 

 

4

 

 

 

 

 

 

 

 

 

 

11

 

 

 

 

 

 

 

14

 

 

 

 

 

 

 

5

 

7

 

 

 

 

 

 

 

 

 

28

 

 

 

6

 

 

 

27

 

 

15

 

 

 

 

 

 

 

 

 

 

 

 

 

 

26

 

33

 

 

 

 

 

 

 

 

 

 

 

 

32

 

34

35

 

 

23

 

31

 

25

 

 

 

 

 

 

 

 

20

 

 

 

 

 

 

 

 

 

 

 

 

 

 

21

 

 

36

 

 

 

 

30

 

 

 

 

 

 

 

 

 

 

24

 

 

 

 

 

 

 

22

19

 

 

37

 

 

 

 

 

38

 

 

 

 

18

 

 

 

 

 

 

 

 

18

 

 

 

 

16

 

 

 

 

 

 

 

 

 

 

39

 

 

 

 

 

 

17

 

 

 

 

 

 

 

18

 

 

 

 

 

 

18

 

 

 

 

 

 

 

29

 

 

 

 

 

 

 

18

 

 

 

29

 

 

 

 

 

 

 

 

 

 

 

Part Name and Description

 

 

 

 

1. Blower Complete

15.

T&P Valve

29.

Burner Assembly

 

 

2. Air Mixing Inlet

16.

Outer Door

30.

Flexible Gas Feedline

 

 

3. Pressure Switch

17.

Right Side Inner Door

31.

Thermal Switch

 

 

4. Blower Temperature Switch

18.

Screw #10-12x 3/4”

32.

Screw #8-18x 1/2”

 

 

5. Blower Gasket

19.

Brass Drain Valve

33.

Burner

 

 

6. Blower Power Cord

20.

Flammable Vapor Sensor Clip

34.

Pilot Assembly

 

 

7. Vent Adapter w/ Vent Term.

21.

Flammable Vapor Sensor

35.

Screw #8-18x 1/2”

 

 

8. Condensate Hose Kit

22.

Flammable Vapor Sensor Harness

36.

Pilot Orifice

 

 

9. Heat Trap Outlet

23.

Thermowell

37.

Manifold Mount

 

 

10. Hot Water Outlet Anode

24.

Gas Control

38.

FVIR Sensor Plate

 

 

11. Flue Baffle

25.

Gas Control Service Tool

39. Orifice

 

 

12. Heat Trap Inlet

26.

3/4” NPT Pipe Plug

40.

Dilution Air Clip

 

 

13. Inlet Dip Tube

27.

ASSE Approved Mixing Valve

 

 

 

 

14. Wire Harness

28.

Kit—HeatTrap Insert

 

 

 

Page 51

51

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