Bradford White 50T65F User manual

The Bradford White
Flammable Vapor Ignition Resistant Water Heater
SERVICE
MANUAL
Troubleshooting Guide
and Instruction for Service
(To be performed ONLY by qualified service providers)
MI30T*F(BN,CX)
MI30S*F(BN, CX)
MI303T*F(BN,CX)
MI40T*F(BN,CX)
MI403S*F(BN,CX)
MI404T*F(BN,CX)
MI503*F(BN,CX)
MI50L*F(BN,CX)
MI504S*F(BN,CX)
MI60T*F(BN,CX)
M430T*F(BN,CX)
M440T*F(BN, CX)
M4403S*F(BN,CX)
M4403T*F(BN,CX)
M450S*F(BN,CX)
M4503*F(BN,CX)
M460T*F(BN,CX)
M1XR403S*F(BN,CX)
M1XR504T*F(BN,CX)
M2XR504T*F(BN,CX)
M2C504T*F(BN,CX)
50T65F(BN,CX)
(*) Denotes Warranty Years.
For the Bradford White
Defender Safety System®Models:
Manual 44943C
Save this manual for future reference

3
Table of Contents
Page Service Procedure
Introduction 3 ---
Trouble shooting Chart 4 - - -
Inner Door Gasket Removal, Inspection, Replacement and Installation
Thermocouple Testing and Replacement
Pilot Assembly Inspection Cleaning and Replacement 10 RG-III
Piezo Igniter and Electrode Testing 11 RG-IV
Combination Thermostat/Gas Valve Testing and Replacement 12 RG-V
Burner Operation Inspection, Adjustment, Cleaning and Replacement 17 RG-VI
Resettable Thermal Switch Testing and Replacement 20 RG-VII
ScreenLok®Flame Arrestor Cleaning 22 RG-VIII
Dip Tube and Anode Inspection and Replacement 23 RG-IX
Generic Parts List 25 - - -
5RG-I
8RG-II
FLAMMABLE VAPOR
IGNITION RESISTANT WATER HEATERS

4
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.

5
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 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. 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 water
with cold water.
1. Turn on gas supply and/or check line
pressure.
2. Review lighting instruction. Set
combination/thermostat
gas valve to correct position.
3. Review lighting instruction. Fully depress
pilot lighting button.
4. Clean, repair or replace.
5. Verify 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 thermocouple to be fully
engulfed by pilot 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 temperature 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 proper operation, replace if
necessary.
1. Verify adequate combustion air is available
to the unit. Check and clear Jacket slot
openings of any dirt, dust, restrictions or
other obstructions. Inspect flame arrestor
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 proper operation, replace if
necessary.
6. Inspect dip tube and replace if necessary.
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 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
TROUBLESHOOTING CHART
Flammable Vapor Ignition Resistant Water Heaters

6
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 combination thermostat/gas valve).
b) Remove (2) 1/4" hex drive screws from right side inner door.
c) Remove (2) 1/4" drive screws from flange section of inner door.
d) Remove (2) 1/4" drive screws from left side inner door.
e) Remove inner door and inspect per step 4. Resettable Thermal Switch
Wire Connection
¼" Hex Drive Screws
Right and Left Side Inner Door.
¼" Hex Drive Screws at
Flange Area of Inner Door
Step 4. Fully inspect inner door gaskets for the following:
>Tears >Other imperfections that will inhibit proper seal
>Missing Material >Gasket adhesion to inner door
>Cracks >Material left on combustion chamber (around opening)
>Dirt or debris
If the gasket is not effected by any of the above, gasket replacement is not required. If replacement is required,
proceed to Inner Door Gasket Replacement Procedure.
Inner Door Gasket Replacement
Procedure.
WARNING
If the information in these instructions is not
followed exactly, a fire or explosion may result causing
property damage, personal injury or death.
Step 5. After inspection of inner door as noted in step 4, completely remove gasket and adhesive residue from right
and left side inner doors as needed.
Step 6. Use RTV sealant (recommended bead size 1/8") to secure the inner door gasket to the inner door sections
(right & left). Refer to illustration on next page for proper application. Note the overlap configuration in the
flange area of the inner door. Set the flange section first, this will help to achieve the proper over lap position.
For White Rodgers Control,
depress knob slightly and rotate
clockwise to the “OFF” position.
For Robertshaw Control, rotate
knob clockwise to the “OFF”
position.
SERVICE PROCEDURE RG-I
Inner Door/Gasket Removal, Inspection
Replacement and Reinstallation

7
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 around the feedline. Using the 1/4” 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,
pilot tube and piezo wire.
SERVICE PROCEDURE RG-I
Inner Door/Gasket Removal, Inspection
Replacement and Reinstallation

8
Step 10. Firmly place right side inner door flange against the left side inner door flange and secure with two ¼” drive
screws from step 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 1/4” 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
¼" drive screws.
SERVICE PROCEDURE RG-I
Inner Door/Gasket Removal, Inspection
Replacement and Reinstallation

9
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)
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 Testing and Replacement

10
THERMOCOUPLE REPLACEMENT
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 (3/8" wrench). 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” position.
For Robertshaw 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
SERVICE PROCEDURE RG-II
Thermocouple Testing and Replacement

11
PILOT/ELECTRODE ASSEMBLY INSPECTION,
CLEANING AND REPLACEMENT
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 (3/8" wrench), pilot tube (7/16" wrench),
and feedline (¾" wench) from combination thermostat/gas valve.
NOTE: Feedline nut for natural gas control
uses right hand threads, LP control uses left hand thread.
Step 5 Disconnect piezo ignition wire from piezo igniter.
Step 6. Remove burner assembly from combustion chamber.
Step 7. Remove pilot/electrode assembly from feedline (¼" drive tool)
Step 8. Inspect pilot for the following:
a) Primary air openings for blockage. Must be free from any
debris (dirt, lint, etc).
b) Kinks or cracks in the pilot tube. If found,
the pilot must be replaced.
Step 9. Inspect pilot orifice:
a) Remove ½" nut from bottom of pilot assembly.
b) Remove pilot tube and pilot orifice.
c) inspect pilot orifice for blockage, must be cleaned or replaced.
Step 10. Install pilot/electrode assembly to feedline, secure with screw from step 7.
Step 11. Re-Install burner assembly into combustion chamber, connect feedline, pilot tube and thermocouple
to combination thermostat/gas valve.
Step 12. Install inner door per SERVICE PROCEDURE RG-I, step 4 through 13.
Step 13. To resume operation follow the instructions located on the lighting instruction label or the lighting instructions
located in the installation and operation manual.
Primary Air
Opening
For White Rodgers Control,
depress knob slightly and rotate
clockwise to the “OFF” position.
For Robertshaw Control, rotate
knob clockwise to the “OFF”
position.
Pilot Orifice
Feedline
Nut
SERVICE PROCEDURE RG-III
Pilot Assembly Inspection, Cleaning and Replacement