Bradford-White MI30T'F User Manual

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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

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)

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)

Manual 238-44943-00D

(*) Denotes Warranty Years

Save this manual for future reference

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 - - -

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.

INTRODUCTION

White Rodgers/Robertshaw Gas Valve Troubleshooting Chart

SYMPTOM PROBABLE CAUSE CORRECTIVE ACTION

Pilot Will Not Light

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 pilo t 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. Defective magnet in combination thermostat/gas valve.

7 Resettable thermal switch has opened.

Pilot Will Not

stay lit

when button is

released

Pilot will light but

the main burner

will not come on

1. Combination thermostat/gas valve set too

low for desired water temperature.

2. Combination thermostat/gas valve temperature is satisfied .

3. Insufficient gas supply or low gas pressure.

4. Combination thermostat/gas valve has

wide differential or is out of calibration.

Pilot goes out

periodically (after

heating cycles,

once a day, once

a week etc.)

1. Insufficient combustion air supply.

2. Incorrect, clogged vent system/ vent

terminal or location.

3. Inconsistent gas supply or gas pressure.

Not enough hot

water

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 thermostat/gas valve is out

of calibration/not functioning.

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

. 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 instructio n. Fully depress pilot lighting button.

4. Clean, repair or re place.

5. Verif y correct electrode 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 pilot flam e.

4. Check thermocouple and replace i f

necessary.

5. Check ECO continuity and replace combina tion th ermost at/gas valve if necessary.

6. Check magne t operation and replace combina tion th ermost at/gas valve if necessary.

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

1. Adjust temperature dial on combination thermostat/gas valve .

2. Check temperature dial setting on

combination thermostat/gas valve.

3. Check gas supply and line p ressur e.

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

1. Verify adequate combustion air is available to the unit. Check an d clear Jacket slot openings of an y dirt, dust, restrictions or other obstructions. Inspect flame arrestor plate and clea n 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 p ressur e.

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 proper operation, replace if necessary.

6. Inspect dip tube and replace if necessary.

SERVICE

PROCEDURE

. See Se rvice P rocedure

RG-V, Page 12.

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

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

6. See Service Procedure RG-IV, Page 11.

4. See Service Procedure

RG-II, Page 8

5. See Service Procedure RG-V, Page 14

6. See Service Procedure RG-V, Page 13

2. See Installation &

operation manual.

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

Flammable Vapor Ignition Resistant Water Heaters

Honeywell Gas Control Troubleshooting Chart

LED Status Control Status Probable Cause

None (LED not on

or flashing

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.

One flash and

three second

pause

LED on

continuously

(Solid)

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

Two flashes and

three second

pause

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

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

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

Flammable Vapor Ignition Resistant Water Heaters

Green LED Indicator

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.

Three flashes and

three second

pause

Insufficient water heating. System will reset.

1. Temperature sensor out of calibration

1. See service procedure RG-VI

Four flashes and

three second

pause

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

LED Status Control Status Probable Cause

Five flashes and

three second

pause

Thermostat/well sensor fault.

Gas Control electronic fault detected.

Seven flashes and

three second

pause

Eight flashes and

three second

pause

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.

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. Reset Gas Control

2. Replace Gas Control.

Replace Gas Control.

Flammable Vapor Ignition Resistant Water Heaters

Green LED Indicator

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.

Water leak detected by accessory module.

Six flashes and

three second

pause

Excessive amount of water in drain pan/water dam.

1. Check T&P valve

2. Check all water fittings.

3. Pressurize and leak test tank.

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.

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.

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

The Bradford White

DEFENDER

Safety System

or White Rodgers Control,

epress knob slightly and rotate

clockwise to the “OFF” position.

For Honeywell Control, rotate k

nob counter-clockwise to the

“OFF” position.

SERVICE PROCEDURE RG-I

Inner Door/Gasket Removal, Inspection

Replacement and Reinstallation

Resettable Thermal Switch

Wire Connection

Hex Drive Screws Right and Left Side Inner Door.

Hex Drive Screws at

Flange Area of Inner Door

Installation of Inner Door With Gasket.

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.

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.

Radiused Channel for

Feedline

Position thermocouple/thermopile,

pilot tube and piezo wire.

PLACE FLANGE

SECTIONS FIRST

RECOMMENDED PATTERN

OR RTV SEALANT

GASKET O

VERLAP MUST BE AS SHOWN ±1/32"

NLARGED

IEW OF

FLANGE AREA

EXPANDED VIEW

VIEW WITH GASKETS

IN PLACE

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.

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.

Verify threaded hole

alignment with slotted

openings in inner door.

Secure flange with

hex drive screws.

SERVICE PROCEDURE RG-I

Inner Door/Gasket Removal, Inspection

Replacement and Reinstallation

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.

CLOSED CIRCUIT THERMOCOUPLE TESTING (White Rodgers Control)

The Bradford White

DEFENDER

Safety System

Probe top terminal on

back of combination

thermostat/gas valve

Alligator clip to copper

sheath of thermocouple

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.

CLOSED CIRCUIT THERMOCOUPLE TESTING (Robertshaw Control)

SERVICE PROCEDURE RG-II

Thermocouple/Thermopile Testing and

Replacement

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.

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.

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.

Thermocouple position

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

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

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.

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

SERVICE PROCEDURE RG-II

Thermocouple/Thermopile Testing and

Replacement

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.).

OPEN CIRCUIT THERMOPILE TESTING (Honeywell Gas Control)

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.

SERVICE PROCEDURE RG-II

Thermocouple/Thermopile Testing and

Replacement

Resettable Thermal Door

Switch Terminal (+)

Jacket Base Screw (-)

+ 28 hidden pages

Bradford-White MI30T'F User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual