Bradford White 55X-80B-3X User Manual
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Manual 238-46647-00B
SERVICE
MANUAL
Troubleshooting Guide
and Instructions for Service
(To be performed ONLY by
qualified service providers)
Models Covered
by This Manual:
GX225S*BN
GX155S*BN
25X78B*N
55X80B*N
M1XR65T*(BN,CX,SX)
MI75S*(BN,CX,SX)
M2XR75S*(BN,CX,SX)
MI100T*(BN,CX,SX)
65T65*(BN,CX,SX)
75T80*(BN,CX,SX)
C(S,D)W275T*(BN,CX,SX)
(*) Denotes Warranty Years
For Models Using White Rodgers,
Robertshaw and Honeywell Gas Control
Atmospheric Gas Water Heaters
(GX155S6BN Model Shown)
Table of Contents
2
Service
Page Procedure
Troubleshooting Chart White Rodgers and Robertshaw Gas Control 3 - - -
Troubleshooting Chart Honeywell Gas Control 4 - - -
Thermocouple Testing and Replacement White Rodgers and Robertshaw Gas Control 6 AG-I
Thermopile Testing and Replacement Honeywell Gas Control 7 AG-I
Pilot Assembly Inspection Cleaning and Replacement
White Rodgers and Robertshaw Gas Control 9 AG-II
Pilot Assembly Inspection Cleaning and Replacement Honeywell Gas Control 10 AG-II
Gas Control Testing and Replacement White Rodgers and Robertshaw 12 AG-III
Gas Control Replacement Honeywell 12 AG-III
Honeywell Thermowell Testing and Replacement 16 AG-III
Honeywell Gas Control and Thermowell Replacement 18 AG-III
Burner Operation Inspection, Adjustment, Cleaning and Replacement 20 AG-IV
Dip Tube and Anode Inspection and Replacement 23 AG-V
Page 2
Troubleshooting Chart
3
For Models Using White Rodgers or Robertshaw Thermostat
Symptom Probable Cause Corrective Action
Pilot will not light
Pilot will not
stay lit
when button is released
1. No incoming gas or too low ga s
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
kinked.
1. Poor thermocouple connection at
gas control.
2. Thermocouple not fully engaged in pilot
assembly bracket.
3. Pilot flame is not fully enveloping the
thermocouple “hot” junct
4. Weak or defective thermocouple.
5. Open ECO on gas control.
6. Defective magnet in gas control.
tube is obstructed or
ion.
1. Turn on gas supply and/or check line
pressure.
2. Review lighting instruction. Set
gas control to correct position.
3. Review lighting instruction. Fully depress
pilot lighting button.
4. Clean, rep
1. Check connection at gas control.
Proper tightness should be finger tight plus
¼ turn.
2. Inspect thermocouple to ensure that it is
fully engaged into pilot bracket.
3. Adju
engul fed by pilot flame.
4. Check thermocouple and replace if
necessary.
5. Check ECO continuity and replace
gas control if necessary.
6. C
gas control if necessary.
air or replace.
st tip of thermocouple to be fully
heck magnet operation and replace
Service
Procedure
1. See Service Procedure
AG-III, Page 12.
4. See Service Procedure
AG-II, Page 9.
4. See Service Procedure
AG-I, Page 6
5. See Service Procedure
AG-III, Page 12
6. See Service Procedure
AG-III, Page 12
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. Gas Control set too low for desired water
temperature.
2. Gas Control temperature is satisfied.
3. Insufficient gas supply or low gas
pressure.
4. Gas Control 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. Gas Control 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. Gas Control is
functioning.
6. Out of spec dip tube is diluting hot water
with cold water.
7. Integrated mixing device is set too low for
desired water temperature.
out of calibration/not
1. Adjust temperature dial on gas control.
2. Check temperature dial setting on
gas control.
3. Check gas supply and line pressure.
4. Check gas control
for proper operation, replace if
ne
cessary.
1. Verify adequate combustion air is available
to the unit. Check and clear Jacket slot
openings of any dirt, dust, restrictions or
other obstructions.
2. Check venting fo
operation
3. Check gas supply and line pressure.
1. Check dial on gas control.
2.Extremely cold water going into the water
heater will decrease the amount of hot
water produced. It may be necessary to
temper incoming water supply.
3. Adjust high demand u
4. Contact Plumbing professional.
5. Check gas control
for proper operation, replace if
necessary.
6. Inspect dip tube and replace if necessary.
7. Reset device using the procedure
i
n the instructions included with the device.
r proper sizing and proper
sage.
2. See Installation &
operation manual.
3. See Service Procedure
AG-III, Page 12
4. See Service Procedure
AG-III, Page 12
3. See Service Procedure
AG-III, Page 12
5. See Service Procedure
AG-III, Page 12
6. See Service Procedure
AG-V, Page 23
Page 3
Troubleshooting Chart
4
For Models Using Honeywell Gas Control
Observe 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:
LED Indicator
LED Status Control Status Probable Cause
Not on and/or
not flashing
One flash and a three
second pause.
LED is on continuously
Two flashes and a three
second pause.
Pilot flame may not be present.
Gas control is in the “PILOT” position and
the pilot flame is detected.
Gas control has recently been turned to the
“OFF” position. Wait until LED goes out
before attempting to relight.
Weak pilot flame detected. System will reset
when pilot flame is sufficient.
Pilot flame is not present.
Gas control is powered and waiting for the set
point knob to be turned to a water
temperature setting.
Gas control was turned to the “OFF” position.
1. Thermopile failure
2. Unstable pilot.
3. Pilot tube blocked or restricted.
Service
Procedure
1. Lite pilot per the instructions
located on the lighting
instructions label or the
lighting instructions located in
the installation and operation
manual.
2. See Service
Procedure AG-I,
Page 7.
Normal operation. Adjust gas
control set point knob to
desired temperature level.
1. Wait for LED to go ou t.
2. Lite pilot per the instructions
located on the lighting
instructions label or the
lighting instructions located in
the installation and operation
manual.
1. See Service
Procedure AG-I,
Page 7
2 & 3. See Service
Procedure AG-II,
Page 10.
Three flashes and a
three second pause.
Four flashes and a three
second pause.
Tank temperature fault.
System will reset.
Excessive tank temperature. Thermowell sensor out of calibration.
Thermowell sensor out of calibration.
Page 4
1. See Service
Procedure AG-III,
Page 16
1. See Service
Procedure AG-III,
Page 16
Troubleshooting Chart (cont.)
5
For Models Using Honeywell Gas Control
LED Status Control Status Probable Cause
Five flashes and a three
second pause.
Seven flashes and a
three second pause.
Eight flashes and a three
second pause.
Thermowell fault
Gas control fault detected.
Pilot flame remains on while gas control is in
the “OFF” position.
1. Damage to thermowell
wires.
2. Thermowell sensor resistance
out of range.
1. Gas control needs to be reset.
2. Gas control is wet or physically
damaged.
Pilot valve stuck in the open position.
Service
Procedure
See Service Procedure
AG-III, Page 16
Lite pilot per the instructions
located on the lighting
instructions label or the
lighting instructions located in
the installation and operation
manual.
Replace gas control.
See Service Procedure
AG-III, Page 18.
Page 5
SERVICE PROCEDURE AG-I
6
Thermocouple Testing and Replacement
For Models Using White Rodgers or
Robertshaw Gas Control
OPEN CIRCUIT THERMOCOUPLE TESTING
Step 1. Disconnect thermocouple from gas control.
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.
Figure 1
Step 3. Following the lighting instruction label on the heater, proceed to light the pilot and allow to operate for
three minutes. A reading of 20 to 30 millivolts indicates good thermocouple output.
NOTE:
It will be necessary to hold the gas control
knob down in the “PILOT” position
continuously throughout this test.
THERMOCOUPLE REPLACEMENT
Step 1. Turn off gas supply to water heater. Rotate knob of gas control to “OFF” position.
For White Rodgers gas
control, depress knob
slightly and rotate
clockwise to the “OFF”
position.
Step 2. Remove outer jacket door.
Figure 2
Figure 3
For Robertshaw gas
control, rotate knob
clockwise to the “OFF”
position.
Step 3. Slide open inner combustion chamber door.
Step 4. Disconnect thermocouple from gas control. 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. Connect other end of thermocouple to gas control (finger tight + ¼ turn).
Step 6. Route carefully through the relief opening in the combustion chamber skirt.
Step 7. To resume operation follow the instructions located on the lighting instruction label or the lighting
instructions located in the installation and operation manual.
Step 8. Slide inner door closed when finished.
Thermocouple position
Page 6
Figure 4
SERVICE PROCEDURE AG-I
7
Thermocouple Testing and Replacement
For Models Using Honeywell Gas Control
OPEN CIRCUIT THERMOPILE TESTING
Step 1. Disconnect red and white thermopile wires from the wire harness leading to the gas control.
Step 2. Using a multimeter capable of reading millivolts, check across thermopile leads.
Step 3. Following the instructions located on the lighting instruction label or the lighting instructions located in the
installation and operation manual, proceed to light the pilot and allow the gas control to operate for three
minutes.
NOTE:
It may be necessary to hold the gas
control knob down in the “PILOT” position
continuously throughout this test.
In an OPEN CIRCUIT test:
Any reading over 400 millivolts
indicates good thermopile output.
For readings under 400 millivolts
replacement of thermopile is
recommended.
Figure 5
CLOSED CIRCUIT THERMOPILE TESTING
Step 1. Closed circuit testing is the preferred method for testing the thermopile. Following the instructions
located on the lighting instruction label or the lighting instructions located in the installation and operation
manual, proceed to light the pilot and allow the control to operate for three minutes.
Step 2. Using a multimeter capable of measuring millivolts, measure across thermopile connections at the
gas control (see Figure 6).
In a CLOSED CIRCUIT test:
Any reading over 300 millivolts
indicates good thermopile output.
For readings under 300 millivolts
replacement of thermopile is
recommended.
It may be necessary to hold the gas
control knob down in the “PILOT” position
continuously throughout this test.
NOTE:
Gas Control
Knob
Thermopile
Connections at gas
control
Figure 6
Page 7
SERVICE PROCEDURE AG-I
8
Thermopile Testing and Replacement
For Models Using Honeywell Gas Control
THERMOPILE REPLACEMENT
Step 1. Turn off the gas supply to the water heater by rotating the gas control knob to the “OFF” position
(see Figure 7).
Step 2. Remove outer jacket door.
Step 3. Remove or slide open the inner combustion chamber door.
Step 4. Disconnect red and white thermopile wires from the wire harness leading
to the gas control.
Step 5. Disconnect the thermopile from the pilot bracket using a 7/16” open-end wrench.
Step 6. Install the new thermopile into the pilot bracket and tighten the threads using care not to damage the
thermopile lead wires. Route new wires through the appropriate opening in the combustion chamber.
Step 7. Reconnect the lead wires being careful to match the colors (red to red and white to white).
Step 8. Reinstall, or slide closed, inner combustion chamber door.
Step 9. Replace the outer door.
Step 10. To resume operation follow the instructions located on the lighting instruction label or the lighting
instructions located in the installation and operation manual.
Gas Control Knob
(Shown in OFF
position)
Figure 7
Page 8
R
9
PILOT ASSEMBLY INSPECTION,
CLEANING AND REPLACEMENT
SERVICE PROCEDURE AG-II
Pilot Assembly Inspection, Cleaning
and Replacement For Models Using White
Rodgers or Robertshaw Gas Control
For White Rodgers gas
control, depress knob
slightly and rotate
clockwise to the “OFF”
position.
Figure 8
Step 1. Turn off gas supply to water heater. Rotate knob
of gas control to “OFF” position.
Step 2. Remove outer jacket door.
Step 3. Slide open inner combustion chamber door.
Step 4. Disconnect thermocouple, pilot tube,
and feedline from gas control.
NOTE: Feedline nut for natural gas control
uses right hand threads, LP control uses left hand thread.
Step 5. Remove burner assembly from combustion chamber.
Step 6. Remove pilot assembly from feedline.
Step 7. 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 8. Inspect pilot orifice:
a) Remove ½" nut from bottom of pilot assembly.
b) Remove pilot tube and pilot orifice.
For Robertshaw gas
control, rotate knob
clockwise to the “OFF”
position.
Figure 10
Pilot Orifice
Figure 11
Figure 9
Feedline Nut
Primary Air
Opening
c) inspect pilot orifice for blockage, must be cleaned or replaced.
Step 9. Install pilot assembly to feedline, secure with screw from step 6.
Step 10. Re-Install burner assembly into combustion chamber, connect feedline, pilot tube and thermocouple
to gas control.
Step 11. Slide inner combustion chamber door closed and re-attach outer jacket door.
Step 12. To resume operation follow the instructions located on the lighting instruction label or the lighting
instructions located in the installation and operation manual.
Page 9
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