Bradford-White U2TW65T-FRN, UTW450S60FR-N, U1TW50S-FRN, UTW465S60FR-N, U1TW60T-FRN User Manual

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Page 1

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 U2TW50T*FRN U2TW65T*FRN UTW450S60FR*N UTW465S60FR*N

(*) Denotes Warranty Years

Manual 238-48385-00A

Save this manual for future reference

Page 2

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

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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:

x Do not try to light any appliance x Do not touch any electrical switch; do not use any phone in your build-

ing

x 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.

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.

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.

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.

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Page 4

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.

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The Bradford White ECO-DEFENDER Safety System

The Bradford White ECO-DEFENDER Safety 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 White ECO-DEFENDER Safety System.

Introduction

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

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 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 inte-

rior 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 En-

ergy Factor and FHSR performance.

The TTW1, TTW2 & 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

Introduction

Page 6

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-resistant combustion 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.

How to Use this Manual

Page 7

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-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 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.

Tools Required

Page 8

ower Supply Dedicated 115VAC, 60 Hz, 15A.

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

pproved Gas Type Natural Gas.

as 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 Servicing

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

Water Supply Pressure

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

TCO Limit Residential 118

F (87oC), Commercial 199oF (93oC).

Residential Temperature Set Point Range

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

Commercial Temperature Set Point Range

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

Blower Temperature Switch

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

Pressure Switch

UTW1 Models:

Normally open, closes on vacuum increase @ -0.68, opens on vacuum decrease @ -0.65

U2TW Models:

Normally open, closes on vacuum increase @ -1.28, opens on vacuum decrease @-1.25

Blower

UTW1 Models:

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

U2TW Models:a,

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

Specifications

Page 9

Vent Tables

Venting Specifications for:

40 Gallon—40,000 BTU/hr.

50 Gallon—40,000 BTU/hr.

0 Gallon—42,000 BTU/hr.

2” Diameter (5.1 cm) PVC Vent Connector Lengths

Terminating # of Elbows

Maximum Straight

ength ft (m)

Minimum Straight

ength ft (m)

hrough 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

Length ft (m)

Minimum Straight

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)

Specifications

Page 10

Vent Tables

Venting Specifications for:

48 Gallon—60,000 BTU/hr.

65 Gallon—60,000 BTU/hr.

3” Diameter (7.6 cm) PVC Vent Connector Lengths

Terminating # of Elbows

Maximum Straight

Length ft (m)

Minimum Straight

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

Length ft (m)

Minimum Straight

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)

Specifications

Page 11

Specifications

Wiring Diagram

Control Timings

Ignition State Timing

Pre-purge 15 seconds

Trial for Ignition 90 seconds

Flame Stabilization Period 3 seconds

Inter-purge 15 seconds

lame 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)

BLOWER

Honeywell

PILOT

SWITCH

BLOWER

SWITCH

PRESSURE

TEMPERATURE

BLOWER

MOTOR

FLAMMABLE VAPOR SENSOR

WATER TEMPERATURE SENSOR

PLUG

RESETTABLE THERMAL

Page 12

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 Flamma-

ble 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-purge period (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.

Sequence of Operation

Page 13

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-purge for 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-light the pilot 4 times. If unsuccessful, the blower is shutdown, and the gas control proceeds to a 5 minute lockout. The gas control re-attempts to 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.

Sequence of Operation

Page 14

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.

Sequence of Operation

Page 15

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 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 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 ig-

niter 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 at-

tempting 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.

Sequence of Operation

Page 16

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.

Sequence of Operation

Page 17

LED Status Control S tatus Probable C ause Service Procedure

None (LED

not on or

flash in

No e le ctrica l p o w e r

Co n trol pow er sw itch in "OFF" position. Su

pply

voltage inte rrupted.

Turn P o w er O n

One short

flash every

four seconds

Stand-by mode,

Thermostat is

satisfied

(

no faults

)

Temperature demand is satisfied (no ca ll for heat)

Normal ope ra tio n

Alternates bright and

dim

(

heartbeat

)

The rmo s tat ca llin g

for he a t (no fault)

Tank temperature below setpoint of thermostat

Normal ope ra tio n

Sho rt flash

once every

second

Weak pilot signal

on la s t call for he a t

1. Uns ta ble p ilo t

2. P ilo t tub e b lo cked o r re s tricted

3. O xid a tion b uild-up o n pilot electrode

4. W ire d a mage to pilo t assembly or bad connection at ga s co ntrol

1. See Burner Inspection on page 20 2-4. See Pilot Inspection, Testing and Replacement on page 22

Tw o fla s hes,

three second

pause

Pressure switch not

working-closed

po s itio n

1. Pressure switch tubing kinked or blocked

2. Blocked pressure tap on sw itch o r b lo w er

3. Fault

ress ure sw itch

1-3. See Pressure Switch Testing on page 25

Three

flashes,

three second

pause

Pressure switch or

blower temperature

switch not working-

open position

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 temperature or exhaust temperature too high

6. Faulty blow er temperature switch

1. Check vent or vent tables 2-3. See Pressure Switch Testing on page 25

4. See Blower Testing on page 28 5-6. See blower Temperature Sw itch Te s ting on p a ge 31

Four flashes,

three second

pause

Excessive tank

temperature,

system must be

reset

1. Thermal well sensor out of calibra tion

2. Faulty gas control

1. Te s t Ga s Contro l & Thermal Well

2. Re p la ce g a s co n trol if necessar

Five flashes,

three second

pause

Fa ls e pilot fla me

present

Pilot va lve stu ck in open p o s ition Re place g a s contro l

bserve 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.

Troubleshooting

Green LED

Page 18

ED S tatus Control S tatus P robable Cause Service P rocedure

Six flas h e s,

one flash,

three second

pause (Soft

Lockout)

Failed to lig ht pilot,

system resets after

(5) min u tes

1. Unstable pilot

2. Pilot tube block or restricted

3. O xid a tion b uild-up o n pilot electrode

4. Wire damage to pilot

assembly or bad connection at

gas valve

1. See Burner Inspection on page 20 2-4. See Pilot Inspection, Testing and Replacement on page 22

ix flas h e s ,

two flashes,

three second

pause (Soft

Lockout)

Pressure switch or

lower temperature

witch opened

during burner

operation. System

resets after (5)

minutes

1. Vent blockage or improper vent configuration

2. Pressure switch tubing kinked or blocked

3. Faulty pressure switch

4. Vent termination being a

ffecte d by w in d

5. Blower not spinning up to speed

6. Blower temperature or exhaust temperature too high

7. Faulty blower temperature switch

1. Check vent o r ve nt tables 2-3. See Pressure Switch Testing on page 25 4

. Refer to venting section

of ins tallatio n manu a l

5. See Blower Testing on page 28 6-7. See Blower Tempe ra ture Sw itch Testing on page 31

Six flas h e s,

three

flashes,

three second

pause (Soft

Lockout)

Pilot flame

extinguished,

system auto resets

after (5) minutes

1. Unstable pilot

2. Pilot tube block or restricted

3. O xid a tion b uild-up o n p ilo t electrode

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

5. Insufficient combustion air

6. Insufficient

gasp

ress ure

1. See Burner Inspection on page 20 2-4. See Pilot Inspection, Testing and Replacement on page 22

5. Refer to Installation & Operation Manual

Six flas h e s,

four flashes,

three second

pause

Undesired false

pilot flame sensed,

system auto resets

Pilot va lve stu ck in o p e n positio n Re pla ce ga s co n trol

Seven

flashes,

three second

pause

Flammable vapor

sensor or

resettable thermal

switch fault

detected, see

warning label

1. Flammable vapor present

2. Flammable vapor sensor exposed to excessive moisture

3. Flammable vapor sensor exposed to extreme ambient temperature

4. Resettable thermal switch o

See Flammable Vapor Sensor Testing on page 40

Eight

flashes, one

flash, three

second

pause

Flammable vapor

sensor out of

spe cification,

possible short

1. Flammable vapor sensor out of spe cification; ve rify Fla mmab le Vapo r Se nsor (FVS) re s ista nce is not below 25 k

.

2. P o s s ib le s h o rt in fla mmable vapor sensor or resettable thermal switch wirin

See Flammable Vapor Sensor Testing on page 40

Troubleshooting

Page 19

ED Status Control Status Probable Cause Service Procedure

Eight flashes, t

hree flashes,

three second

pause

Thermal well sensor

damaged or unplugged or gas cont

rol electronics fault

detected

1. Damage to thermal well wires

2. Thermal well sensor resistance out of range

3. Replace thermal well

4. Verify control is not wet or physically damaged

5. Reset control on/off switch

6. Replace gas control if 8-3 error persists

See Thermal Well Testing on page 34

Eight flashes,

our flashes,

hree second

pause

as control fault

detected

1. Verify control is not wet or physically damaged

2. Reset control on/off switch

3. Replace gas control if 8-4 error persists

1. Replace gas control if wet or physically damaged 2

. Cycle power

3. Replace gas control

Troubleshooting

Page 20

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.

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

Step 3. Turn off the gas supply to the water heater.

Step 4. Remove the outer door.

Burner Maintenance

Gas control power

switch

TTW (water heater)

power cord

Outer door

Page 21

Burner Cleaning Procedure (cont’d)

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

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

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.

Step 8. Disconnect the spark igniter/flame sensor wire from gas control.

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

Step 10. Remove manifold mount from burner inner door by removing (2) 1/4” hex drive screws.

Burner Maintenance

(4) 1/4” hex drive

screws

Pilot and main

feedlines

Spark igniter/flame

sensor wire

Gas control

Burner assembly

Right side

inner door

(3) 1/4” hex drive screws

Left side

burner door

(2) 1/4” hex drive screws

Page 22

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.

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.

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

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

Pilot Maintenance

Gas control power

switch

Burner screen

Burner venturi

Manifold mount

Feedline

Main burner orifice

Page 23

Pilot Inspection, Testing and Replacement (cont’d)

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

Step 3. Turn off the gas supply to the water heater.

Step 4. Remove the outer door.

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

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.

Step 7. Disconnect the spark igniter/flame sensor wire from gas control.

Pilot Maintenance

Pilot and main

feedlines

Outer Door

TTW (water heater)

power cord

(4) 1/4” hex drive

screws

Right side

inner door

Spark igniter/flame

sensor wire

Gas control

Page 24

Pilot Inspection, Testing and Replacement (cont’d)

Step 8. Remove the burner assembly from the combustion chamber.

Step 9. Remove the pilot assembly from the main feedline using a 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.

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 14. Visually inspect the pilot tubing for kinks or cracks. If damage is found, replace the pilot assembly.

Pilot Maintenance

Multi-meter

Burner assembly

Pilot assembly

1/4” nut driver

Page 25

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

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 pressure switch from blower housing (see photo 2).

Pressure Switch Testing

Gas control power

switch

WARNING

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

personal injury.

1 2

Pressure Switch

Page 26

Pressure Switch Testing (cont’d)

Pressure Switch Testing

Pressure switch

wire leads

ith steps 1,2 & 3

complete, discon-

nect wire leads

from pressure

switch.

Use a multi-meter

set to the ohms

setting. With

blower off, check

across the pres-

sure switch termi-

nals. Are the

switch contacts

open (no electrical

continuity)?

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?

The switch contacts

are OK. See safety

circuit trace (page

40).

Check the tubing and

pressure tap on switch

for blockage. Is there

a blockage?

Check the tubing and pressure tap on switch for

blockage. Is

there a block-

age?

Clear blockage

Replace switch (see page 27).

Is the vent

system

blocked?

Is vent system

length within the

vent table specifi-

cations listed on

pages 9 & 10?

Reconfigure vent

system to be

compliant with

vent tables.

See blower

testing (page

28). Is the

Blower OK?

Correct the

blower prob-

lem.

Page 27

Pressure Switch Replacement

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.

Step 3. Carefully remove pressure switch from blower housing.

Step 4. Disconnect tubing from the pressure switch.

Pressure Switch Replacement

Gas control power

switch

WARNING

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

personal injury.

Control access

cover

Slide pressure switch

in direction of arrow

while tilting slightly

away from blower

housing

Control access

cover

Pressure switch

tubing

Page 28

Step 5. Disconnect yellow wires from the pressure switch.

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

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

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

Blower Testing

Gas control power

switch

Yellow pressure

switch wires

WARNING

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

personal injury.

Control access

cover

Page 29

Blower Testing (cont’d)

Does blower

energize within

2 minutes?

Disconnect pressure switch tub-

ing from blower

(see photo 3).

Connect manome-

ter to pressure tap

of blower (see

photo 3).

Disconnect vent

system from top of

blower and remove

vent adapter (see

photo 5).

Does blower

nergize after 2 minutes, run for 30 seconds

and shut

down?

Disconnect

cord set in

photo 9. Is

there 115VAC

across termi-

nals shown in

photo 11?

Is there

115VAC at

wall outlet?

Replace blower.

Repair or replace

power cord.

Determine

power source

problem and

correct.

Is there 115VAC

across termi-

nals shown in photo 7?

Incorrect supply voltage polarity.

Reconnect cord set

shown in photo 4.

Is there 115VAC

between blue wire

and ground wire

(see photo 8).

Replace blower.

Does cord set

have electrical

continuity?

Replace cord

set.

Replace gas

control.

See pressure

switch testing

on page 25.

With blower running and

exhaust adapter removed

from top of blower, is there

a negative pressure of –

2.15” to –2.30” W.C.

Blower OK.

Is there 115VAC across blue

and green wires (see photo 8).

Replace blower.

Determine volt-

age problem and

correct.

Remove exhaust

adapter

ressure tap.

Pressure

switch tubing

6 7

Green ground

wire

Blue wire

Shown with pressure

switch removed

Blower Testing

Y Y

Check power cord

for damage.

Page 30

Blower Removal

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

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

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

Step 6. Unplug cord sets from blower.

Step 7. Remove the three blower 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.

Gas control power

switch

TTW (water heater)

power cord

Blower cord

sets

Blower mount-

ing screws

Remove exhaust

adapter and retain

for use on new

blower

Remove dilution air

clip and retain for

use on new blower

Locating pins on

blower flange

Pin location holes

in jacket head

Blower Replacement

Page 31

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

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

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

Step 3. Locate the blower temperature switch.

Gas control power

switch

Control access

cover

Blower temperature

switch location

Air mixing

inlet

WARNING

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

personal injury.

Blower Temperature Switch Testing

Page 32

Blower Temperature Switch Testing (cont’d)

witch Setting

Opens on rise @ approximately 165oF

uto resets on fall @ approximately 160

Cool switch to

below 160

Reconnect wire leads and ob-

serve heater operation. Do

exhaust gas temperatures

rise to or above 170

F with

vent connected?

Replace switch (see page 33).

Disconnect wire leads to

switch. Using multi-meter set

to the ohms setting. Is there

continuity between the switch

terminals?

Do switch

contacts

open?

Exhaust

temperature

is too hot.

Do switch con-

tacts open?

Replace switch (see page 33).

Switch OK

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

Blower Temperature Switch Testing

Page 33

Blower Temperature Switch Replacement

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.

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.

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.

WARNING

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

personal injury.

Gas control power

switch

Control access

cover

Blower temperature

switch location

Snip retaining lug from

blower housing

Blower Temperature Switch Replacement

Page 34

Thermal Well Testing

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.

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

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

Thermal Well Testing

CAUTION

Do not use standard multi-meter probes for this testing. Doing so will damage the connector. Use special pin type e

lectronic probes or small diameter wire pins inserted into connector.

Thermal well connector

Page 35

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

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.

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.

Determine Tank Temperature

WARNING

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

Gas control power

switch

Page 36

Sensor Resistance at Various Temperatures

Gas Control & Thermal Well Removal From Water Heater

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

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

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.

Component Disassembly

°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 10000 9760 9526 8

0 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

n Degrees F

Gas control power

switch

TTW (water heater)

power cord

Page 37

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.

Step 5. Disconnect the wire harnesses and spark igniter/ flame sense wire from the gas control.

Step 6. Remove the gas control & thermal well by rotating the flats of the Thermal Well counter clockwise using a 1-5/16” wrench.

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.

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

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

Gas Control Removal

Pilot and main

feedlines

Spark igniter/flame

sensor wire

Gas control

Flats of thermal

well

Gas control power

switch

TTW (water heater)

power cord

Page 38

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.

Step 5. Disconnect the wire harnesses and spark igniter/ flame sense wire from the gas control.

Step 6. Using the gas control service tool, p/n 239-4599100, available from your BWC parts supplier, insert the tool into the back of the gas control.

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.

Gas Control Assembly

ilot and main

feedlines

Spark igniter/flame

sensor wire

Gas control

Gas control service

tool

Page 39

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

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

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

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

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

Gas Control Assembly

Wire leads on

thermal well

Relief opening

Slots in thermal well

Tabs on back of gas

control

Pilot and main

feedlines

Wire harnesses

Page 40

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

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

Step 2. Disconnect the flammable vapor sensor harness from the gas control.

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.

115 VAC Circuit Trace

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

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

Flammable Vapor Sensor Testing

CAUTION

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

Gas control power

switch

Flammable vapor

sensor harness

Flammable vapor

sensor harness

Page 41

115 VAC Circuit Trace

WARNING

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

personal injury.

LED status:

one, control

LED not on or

flashing.

LED status:

hort flash

once every four

seconds.

LED status:

“

Heartbeat”,

alternates

bright/dim.

LED status:

arious flash-

ing error codes.

Waiting for call

for heat.

Thermostat call-

ing for heat.

Verify error

code as listed

on page 17.

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?

Check for damage

to AC supply

power cord.

Repair damage.

Replace blower.

Is there 115VAC across terminals

shown in photo 11?

Incorrect supply voltage polarity.

Reconnect cord set

shown in photo 9.

Disconnect wire har-

ness from gas control

(see photo 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

black & white wire as

shown in photo 13?

Call for technical support.

Replace gas control.

Wire harness

Check for 115VAC between black and white wires.

-NOTE-

Electronic meter probes required. Use car not to

damage connector during this check.

Wire sheath pulled back to

identify wire colors

Page 42

Safety Circuit Voltage Trace

Note: This procedure assumes a cold tank.

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

cover.

Safety Circuit Voltage Trace

WARNING

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

personal injury.

Control access

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).

Is LED on gas valve flash-

ing the “heartbeat” code

(alternating bright/dim)?

No voltage from gas control.

Call for technical support.

Verify 115VAC to gas con-

trol (see page 41).

Is there 10 to 13VAC between

the yellow wire leading from the

pressure switch and the green

ground wire (see photo 27)?

Is there continuity through

the blower temperature

switch (see page 31)?

Check for loose or broken wire connection at switch

terminals.

Do you hear or can you

see the igniter sparking?

Check igniter/sensor (see page

22). Is igniter/sensor OK?

Correct igniter/

sensor problem

Determine cause of blower temperature switch activa-

tion and correct.

Faulty cord set

or gas control

Safety circuit

voltage is OK.

If burner does not light, ob-

serve LED flash code on gas

control and refer to trouble-

shooting section on page 17.

Green ground wire

Red sire leading to

blower temp. switch

Yellow wire leading

from pressure switch

N Y

Page 43

Remove the Blower to Gain Access to the Flue Baffle

Step 1. Move the gas control p ow e r switch to the “OFF” position.

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

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

Step 4. Unplug the cord sets from the blower.

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

Blower Removal

as control power

switch

TTW (water heater)

power cord

Exhaust adapter

Blower mounting

screws

Blower cord sets

Flue baffle

Page 44

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

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

Dip Tube Inspection

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.

Page 45

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/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

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 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-half the 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.

Anode Inspection

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.

Page 46

Inner Door Removal Procedure

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

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

Step 3. Remove the outer door.

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

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

Inner Door Removal

as control power

switch

Blower (water

heater) power cord

Connectors attached to

resettable thermal switch

Outer door

(3) 1/4” hex drive screws

(4) 1/4” hex drive

screws

Right side

inner door

Page 47

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

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.

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

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

If any of the imperfections above are present, replace the inner door gasket following the Inner Door Gasket 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.

Step 2. U s i n g

RTV sealant, apply a 1/8” bead to secure

the

Inner Door Gasket Replacement

Flammable vapor

sensor

Flammable vapor

sensor clip

WARNING

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

Recommended pattern for RTV sealant

Expanded view Slice gasket here to slide over burner venturi

Gasket overlap must be

as shown ± 1/32

Enlarged

view of

flange

area

Gasket overlap must be

as shown ± 1/32

Page 48

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

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-tighten the 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-tighten the

Inner Door Installation

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.

Page 49

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

Step 8. Re-install the 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-install the burner assembly.

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

Step 11. Re-install the 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.

Arrestor Cleaning

Page 50

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

____________________________________________________________

Common Terms

Page 51

Parts List

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 #10-12 x 3/4” 32. Screw #8-18 x 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 #8-18 x 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—Heat Trap Insert

Page 52

parts@bradfordwhite.com

techserv@bradfordwhite.com

www.bradfordwhite.com

Bradford-White U2TW65T-FRN, UTW450S60FR-N, U1TW50S-FRN, UTW465S60FR-N, U1TW60T-FRN User Manual

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Frequently Asked Questions

User Manual