Bradford-White Corp Flammable Vapor Ignition Risistant Water Heaters User Manual

Flammable Vapor Ignition

Resistant Water Heaters

Gas Water Heaters

SERVICE

MANUAL

Troubleshooting Guide

and Instructions for Service

(To be performed ONLY by

qualified service providers)

FEATURING

Manual 238-44943-00D

For the Bradford White

Defender Safety System

Models:

MI30T*F(BN,CX,SX) MI30S*F(BN, CX,SX) MI303T*F(BN,CX,SX) MI40T*F(BN,CX,SX) MI403S*F(BN,CX,SX) MI404T*F(BN,CX,SX) MI503*F(BN,CX,SX) MI50L*F(BN,CX,SX) MI504S*F(BN,CX,SX) MI60T*F(BN,CX,SX) C(S,D)W2504T*F(BN,CX,SX)

Save this manual for future reference

M430T*F(BN,CX,SX) M440T*F(BN, CX,SX) M4403S*F(BN,CX,SX) M4503*F(BN,CX,SX) M460T*F(BN,CX,SX) M1XR403S*F(BN,CX,SX) M1XR504T*F(BN,CX,SX) M2XR504T*F(BN,CX,SX) M2XR65T*F(BN,CX,SX) M2C504T*F(BN,CX,SX) 50T65F(B*N,C*X,S*X) 65T65F(B*N,C*X,S*X)

(*) Denotes Warranty Years

The Bradford White

DEFENDER

Safety System

Flammable Vapor Ignition Resistant Water Heaters

Table of Contents

Page Service Procedure

Introduction 3 - - -

Trouble shooting Chart 4 - - -

Inner Door Gasket Removal, Inspection, Replacement and Installation 7 RG-I

Thermocouple/Thermopile Testing and Replacement 10 RG-II

Pilot Assembly Inspection Cleaning and Replacement 13 RG-III

Piezo Igniter, Electrode Testing and Replacement 14 RG-IV

White Rodgers/Robertshaw Gas Valve Testing and Replacement 15 RG-V

Honeywell Gas Control Testing, Disassembly, and Replacement 20 RG-VI

Burner Operation Inspection, Adjustment, Cleaning and Replacement 31 RG-VII

Resettable Thermal Switch Testing and Replacement 34 RG-VIII

ScreenLok®Flame Arrestor Cleaning 36 RG-IV

Dip Tube and Anode Inspection and Replacement 37 RG-X

Generic Parts List 39 - - -

INTRODUCTION

The Bradford White DEFENDER Safety System

The Bradford White DEFENDER Safety System®was designed to resist the ignition of flammable vapors that can occur outside of the water heater. 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 DEFENDER Safety System.

How the Safety System Works

During normal operation, air for combustion is drawn into the water heater through the opening in the jacket. This air travels down and around the combustion chamber and enters through holes in the very 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 supplied gas and is efficiently combusted, producing very low NOx emissions.

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

Should the flammable vapors continue to the burner, the flame arrestor plate prevents the flames from traveling backwards and igniting vapors outside of the combustion chamber. The calibrated, multipurpose thermal switch recognizes this and shuts down the pilot and main burner. This switch also deactivates the burner and pilot in the unlikely event of restricted airflow caused by severe lint, dust or oil accumulation on the arrestor plate.

White Rodgers/Robertshaw Gas Valve Troubleshooting Chart

Flammable Vapor Ignition Resistant Water Heaters

SYMPTOM PROBABLE CAUSE CORRECTIVE ACTION

1. Turn on gas supply and/or check line pressure.

2. Review light ing instruction. Set combination/thermostat gas valve to correct position.

3. Review light ing instruction. Fully depress pilot lighting button.

4. Clean, repair or re place.

5. Verif y correct elec trode position. Replace pilot assembly.

6. Replace Piezo igniter.

1. Check connection at combination thermostat/gas valve. Proper tightness should be finger tight plus ¼ turn.

2. Inspect thermocouple to ensure that it is fully engaged into pilot bracket.

3. Adjust tip of therm ocouple to be fully engulfed by pi lot flame.

4. Check thermocouple and replace if necessary.

5. Check ECO continuity and replace combination thermostat/gas valve if necessary.

6. Check magnet operation and replace combination thermostat/gas valve if necessary.

7. Determine cause of switch activation. To reset, depress button on resettable thermal switch located on inner door.

1. Adjust temp erature dial on combination thermostat/gas valve.

2. Check temperature dial setting on combination thermostat/gas valve.

3. Check gas supply and line pressure.

4. Check combination thermostat/gas valve for prop er operation, replace if necessary.

1. Verify adequate combustion air is available to the unit. Check and clea r Jack et slot openings of an y dirt, dust, restrictions or other obstructions. I nspect flame arresto r plate and clean with stiff bristled brush and/or vacuum to remove any debris accumulation.

2. Check venting for proper sizing and proper operation

3. Check gas supply and line pressure.

1. Check dial on combination thermostat /gas valve.

2.Extremely cold water going into the heater will decrease the amount of hot water produced. It may be necessary to temper incoming water supply.

3. Adjust high demand usage.

4. Contact Plumbing professional.

5. Check combination thermostat/gas valve for prop er operation, replace if necessary.

6. Inspect dip tube and replace if necessary.

Pilot Will Not Light

Pilot Will Not

stay lit

when button is

released

Pilot will light but

the main burner

will not come on

Pilot goes out

periodically (after

heating cycles,

once a day, once

a week etc.)

Not enough hot

water

1. No incoming gas or too low gas pressure.

2. Gas control knob set to wrong position.

3. Pilot light button not being fully depressed when attempting to light pilot.

4. Pilot orifice or pilot tube is obstructed or kinked.

5. Pilot electrode not sparking to pilot.

6. Piezo igniter not functioning.

1. Poor thermocouple connection at combination thermostat/gas valve.

2. Thermocouple not fully engaged in pilot assembly bracket.

3. Pilot flame is not fully enveloping the thermocouple “hot” junction.

4. Weak or defective thermocouple.

5. Open ECO on combination thermostat/ gas valve.

6. Defe ctive magnet in comb ination thermostat/gas valve.

7 Resettable thermal switch has opened.

1. Combination thermostat/gas valve set too low for desired water temperature.

2. Combination thermostat/gas valve temperat ure is satisfied.

3. Insufficient gas supply or low gas pressure.

4. Combination thermostat/gas valve has wide differential or is out of calibration.

1. Insufficient combustion air supply.

2. Incorrect, clogged vent system/ vent terminal or location.

3. Inconsistent gas supply or gas pressure.

1. Combination thermostat/gas valve set too low for desired water temperature.

2. Cold inlet water temperature is very cold.

3. High demand periods.

4. Incorrectly sized water heater for application.

5. Combination thermosta t/gas valve is out of calibration/not fu nctioning.

6. Out of spec dip tube is diluting hot water with cold water.

SERVICE

PROCEDURE

1. See Service Procedure RG-V, Page 12.

4. See Service Procedure RG-III, Page 10.

5. See Service Procedure RG-III, Page 10.

6. See Service Proce dure RG-IV, Page 11.

4. See Service Proce dure RG-II, Page 8

5. See Service Procedure RG-V, Page 14

6. See Service Procedure RG-V, Page 13

2. See Installation & operation man ual.

3. See Service Procedure RG-V, Page 12

4. See Service Procedure RG-V, Page 12

1. See Service Procedure RG-VIII , Page 22

3. See Service Procedure RG-V, Page 12

5. See Service Procedure RG-V, Page 12

6. See Service Procedure RG-IX, Page 23

Honeywell Gas Control Troubleshooting Chart

Flammable Vapor Ignition Resistant Water Heaters

Observe green LED indicator on Gas Control. Error flash codes are displayed with a three second pause before repeating. Check and repair the system as noted in the troubleshooting table below.

Green LED Indicator

LED Status Control Status Probable Cause

1. Gas Control is functioning normally.

2. Gas Control is not powered. Light pilot.

3. Thermopile failure.

Gas Control is powered and waiting for the set point knob to be turned to a water temperature setting.

Set point knob was turned to “OFF” position.

1. Thermopile failure

2. Unstable pilot

3. Pilot tube block or restricted.

4. Resettable thermal switch has opened

None (LED not on

or flashing

One flash and

three second

pause

LED on

continuously

(Solid)

Two flashes and

three second

pause

Gas Control is operating normally. Pilot flame may not be present. Check for pilot flame through sight glass and light if necessary.

If set point knob is in “PILOT” position then pilot flame is detected. Turn set point knob to desired setting.

Set point knob has been recently turned to the “OFF” position. Wait until LED goes out before attempting to relight

Weak pilot signal detected. System will reset when pilot flame is sufficient.

Service

Procedure

If the pilot will not stay lit replace pilot assembly. If problem persists replace Gas Control.

Normal operation. Adjust thermostat to desired temperature setting.

LED will go out and the control will function normally when the pilot is lit.

1. See service procedure RG-II

2. See service procedure RG-III

3. See service procedure RG-III

4. See service procedure RG-VIII

Three flashes and

three second

pause

Four flashes and

three second

pause

Insufficient water heating. System will reset.

Excessive tank temperature. System must be reset.

1. Temperature sensor out of calibration

2. Faulty Gas Control

1. See service procedure RG-VI

2. See service procedure RG-VI

Honeywell Gas Control Troubleshooting Chart

Flammable Vapor Ignition Resistant Water Heaters

Observe green LED indicator on Gas Control. Error flash codes are displayed with a three second pause before repeating. Check and repair the system as noted in the troubleshooting table below.

Green LED Indicator

LED Status Control Status Probable Cause

Five flashes and

three second

pause

Six flashes and

three second

pause

Seven flashes and

three second

pause

Eight flashes and

three second

pause

Thermostat/well sensor fault.

Water leak detected by accessory module.

Gas Control electronic fault detected.

Standing pilot remains on while set point knob is in “OFF” position.

1. Damage to the temperature sensor.

2. Temperature sensor resistance out of range.

Excessive amount of water in drain pan/water dam.

1. Control need to be reset.

2. Control is wet or physically damaged.

Pilot valve stuck in open position.

Service

Procedure

1. See service procedure RG-VI

1. Check T&P valve

2. Check all water fittings.

3. Pressurize and leak test tank.

1. Reset Gas Control

2. Replace Gas Control.

Replace Gas Control.

The Bradford White

DEFENDER

SERVICE PROCEDURE RG-I

Inner Door/Gasket Removal, Inspection

Replacement and Reinstallation

Safety System

Inner Door Removal Procedure

Step 1. Rotate knob of the combination

thermostat/gas valve to the “OFF” position.

Step 2. Remove outer jacket burner access door

Step 3. Inner Door Removal.

a) Disconnect resettable thermal switch wire leads (leading from Gas Control/gas valve). b) Remove (2) hex drive screws from right side inner door. c) Remove (2) hex drive screws from flange section of inner door. d) Remove (2) hex drive screws from left side inner door. e) Remove inner door and inspect per step 4.

Hex Drive Screws at

Flange Area of Inner Door

For Honeywell Control, rotate knob counter-clockwise to the “OFF” position.

For Robertshaw Control, rotate knob clockwise to the “OFF” position.

Resettable Thermal Switch

Wire Connection

Hex Drive Screws Right and Left Side Inner Door.

For White Rodgers Control, depress knob slightly and rotate clockwise to the “OFF” position.

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

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

If the gasket is not effected by any of the above, gasket replacement is not required. If replacement is required, proceed to Inner Door Gasket Replacement Procedure.

Inner Door Gasket Replacement Procedure.

WARNING

If the information in these instructions is not

followed exactly, a fire or explosion may result causing

property damage, personal injury or death.

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

and left side inner doors as needed.

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

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

PLACE FLANGE

SECTIONS FIRST

RECOMMENDED PATTERN

FOR RTV SEALANT

EXPANDED VIEW

SERVICE PROCEDURE RG-I

Inner Door/Gasket Removal, Inspection

Replacement and Reinstallation

GASKET OVERLAP MUST BE AS SHOWN ±1/32"

VIEW WITH GASKETS

IN PLACE

ENLARGED VIEW OF FLANGE AREA

Installation of Inner Door With Gasket.

Step 7. Clean any residual gasket residue or other debris

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

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

Firmly position the radiused channel of the inner door aroundthe feedline. Using the (2) hex drive screws from step 3d, secure left side inner door in place. DO NOT OVER TIGHTEN SCREWS.

Step 9 Position thermocouple, pilot tube and Piezo wire

against left side inner door flange gasket.

DO NOT ROUTE THROUGH RADIUSED CHANNEL WITH FEEDLINE.

WARNING

Stripped fastener connections may allow

for seal breach of inner door. A seal

breach may result in a fire or explosion

causing property damage, personal injury

or death. Do not over tighten screws in

steps 8, 10 and 11.

If a fastener connection is stripped,

contact the manufacturer listed on the

water heater rating plate.

Position thermocouple/thermopile,

pilot tube and piezo wire.

Radiused Channel for

Feedline

SERVICE PROCEDURE RG-I

Inner Door/Gasket Removal, Inspection

Replacement and Reinstallation

Step 10. Firmly place right side inner door flange against the left side inner door flange and secure with (2) hex drive

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

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

chamber are aligned with the right side inner door slotted opening. Verify seal integrity around combustion opening. Secure right side inner door using (2) hex drive screws from step 3b. DO NOT OVER TIGHTEN SCREWS. Verify both left and right sides of the inner door are properly positioned and sealed against the combustion chamber.

Secure flange with

hex drive screws.

Verify threaded hole

alignment with slotted

openings in inner door.

Step 12. Reconnect lead wires from combination thermostat/gas valve to resettable thermal switch (See photo in step

3). Note, wire terminations are interchangeable with either resettable thermal switch connections.

Step 13. Replace outer jacket burner access door.

Step 14. To resume operation follow the instructions located on the lighting instruction label or the lighting instructions

located in the installation and operation manual.

The Bradford White

DEFENDER

SERVICE PROCEDURE RG-II

Thermocouple/Thermopile Testing and

Replacement

Safety System

CLOSED CIRCUIT THERMOCOUPLE TESTING (White Rodgers Control)

Step 1. Closed circuit testing is the preferred method for testing thermocouple. Following the lighting instruction

label on the heater, proceed to light the pilot and allow to operate for three minuets. If the pilot will not stay lit, hold the pilot button (located on the combination thermostat/gas valve) down during this test

Step 2. Using a multimeter capable of measuring millivolts, connect one lead

using an alligator clip to the copper sheath of the thermocouple, use the second lead of the multi meter to probe the top terminal located at the back of the combination thermostat/gas valve.

Step 3. If meter reads 10 millivolts or higher, the thermocouple is OK. If reading is below 10 millivolts,

replace the thermocouple.

Probe top terminal on

back of combination

thermostat/gas valve

Alligator clip to copper

sheath of thermocouple

CLOSED CIRCUIT THERMOCOUPLE TESTING (Robertshaw Control)

Step 1. Disconnect thermocouple from combination thermostat/gas valve.

Step 2. Connect a thermocouple adaptor

(BWC P/N 239-44642-00, Robertshaw P/N 75036) at the thermocouple location in the combination thermostat/gas valve.

Step 3. Reconnect thermocouple to adaptor. Make certain all

connections are tight (finger tight plus ¼ turn)

Step 4 Using a multimeter capable of measuring millivolts, connect

one alligator clip to the set screw of the adaptor, and the other alligator clip to copper portion of the thermocouple.

Step 5. Following the lighting instruction label on the heater, proceed to light the pilot and allow to operate for

three minuets. If the pilot will not stay lit, hold the red reset button (located on the combination thermostat/gas valve) down during this test

Step 6. If meter reads 13 millivolts or higher, the thermocouple is OK. If reading is below 13 millivolts

replace the thermocouple.

SERVICE PROCEDURE RG-II

Thermocouple/Thermopile Testing and

Replacement

OPEN CIRCUIT THERMOCOUPLE TESTING (White Rodgers/Robertshaw Gas Valve)

Step 1. Disconnect thermocouple from combination thermostat/gas valve.

Step 2. Using a multimeter capable of measuring millivolts, connect

one alligator clip to the end ball or contact portion of the thermocouple, and the other alligator clip to copper portion of the thermocouple.

Step 3. Following the lighting instruction label on the heater, proceed to light the pilot and allow to operate for

three minutes. It will be necessary to hold the pilot button down continuously throughout this test. A reading of 20 to 30 millivolts indicates good thermocouple output.

THERMOCOUPLE REPLACEMENT (White Rodgers/Robertshaw Gas Valve)

Step 1. Turn off gas supply to water heater. Rotate knob of combination

thermostat/gas valve to “OFF” position.

For White Rodgers Control, depress knob slightly and rotate clockwise to the “OFF” position.

For Rober tshaw Control, rotate knob clockwise to the “OFF” position.

Step 2. Remove outer jacket door.

Step 3. Remove right side of inner door per SERVICE PROCEDURE RG-I, steps 3a through 3c.

Step 4 Disconnect thermocouple from combination thermostat/gas valve. Locate other end of

thermocouple inside of combustion chamber and remove from pilot bracket. Pull firmly pulling away from the pilot assembly.

Step 5. Install new thermocouple into pilot bracket making certain the thermocouple is fully engaged into the pilot

bracket. Position thermocouple against left side inner door flange at its original position. Connect other end of thermocouple to combination thermostat/gas valve (finger tight + ¼ turn).

Step 6. Inspect inner door gasket per

SERVICE PROCEDURE RG-I, Step 4.

Thermocouple position

Step 7. Install right side inner door per

SERVICE PROCEDURE RG-I, Step 10 through Step 13

Step 8. To resume operation follow the instructions located on the lighting instruction label or the lighting

instructions located in the installation and operation manual.

SERVICE PROCEDURE RG-II

Thermocouple/Thermopile Testing and

Replacement

OPEN CIRCUIT THERMOPILE TESTING (Honeywell Gas Control)

The following test should be performed while the pilot flame is on.

Step 1. Turn knob to pilot position and depress.

Step 2. Continue pressing knob and remove red (+) wire from resettable thermal door switch.

Step 3. Using a multimeter capable of measuring millivolts, connect the positive side of the multimeter to the

terminal of the resettable thermal door switch. Connect the negative side of the multimeter to any earth ground location (jacket base, screw, etc.).

Resettable Thermal Door

Switch Terminal (+)

Jacket Base Screw (-)

Normal thermopile operation will be between 350mV - 850mV. If reading is less than 350mV, replacement of pilot assembly is recommended following SERVICE PROCEDURE RG-III.

Step 4. If thermopile reading is between 350mV - 850mV, remove multimeter and reconnect red wire to positive (+)

terminal of Gas Control.

Step 5. Release Gas Control knob and turn to desired setting to resume normal operation.

+ 28 hidden pages

Bradford-White Corp Flammable Vapor Ignition Risistant Water Heaters User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual