Bradford White U-4-XRTW65T6FRN - Manual (Page 3)

3
(Replaces pg. 42 (238-45637-00) or pg. 38 (238-48933-00) in
instruction manual.)
Troubleshooting continued-
Six flashes-four
flashes, three second
pause Undesired-false pilot
flame sensed.
System auto resets.
Seven flashes, three
second pause
Flammable vapor
sensor fault detected,
see warning label
Eight flashes-one flash,
three second pause
Flammable vapor
sensor out of
specification. Possible
short.
Eight flashes-three
flashes, three second
pause
T'stat well & sensor
damaged or unplugged
or
Gas valve electronics
fault detected
LED Status Control Status Probable Cause
Pilot valve stuck in open position.
1. Flammable vapor present
2. Flammable vapor sensor exposed to excessive
moisture
3. Flammable vapor sensor exposed to extreme
ambient temp
4. Resettable thermal switch open.
1. Flammable vapor sensor out of specification
2. Possible short in flammable vapor sensor or
resettable thermal switch wiring.
1. Damage to thermowell wire.
2. Thermowell sensor resistance out of range.
3. Replace thermowell.
4. Verify control is not wet or physically damaged
5. Reset control on/off switch.
6. Replace electronic module if 8-3 error persists
Eight flashes-four
flashes, three second
pause
Gas valve 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
Pilot flame
extinguished.
System resets after 5
minutes.
1. Unstable pilot.
2. Pilot tube blocked or restricted.
3. Oxidation build up on pilot electrode.
4. Wire damage to pilot assembly or bad
connection at gas valve.
5. Insufficient combustion air.
Six flashes-three
flashes, three second
pause (Soft lockout)
Fault Probable Cause
Resettable thermal switch tripped
(open) 1. Burner failure.
2. Flammable vapor present.
Control Sequence of Operation
Start up Sequence
Upon powering up, the control checks for the presence of the vapor sensor, if
the resistance is in the expected range the control will begin normal operation
after 5 to 8 seconds.
Normal Heating Sequence
1. The thermostat senses a need for heat.
2. The control checks the pressure switch condition.