Bradford White U-TW4-75S-76R-3N - Manual (Page 13)

Six-four flash, three
second pause
Undesired-false
pilot flame sensed.
System auto resets.
Seven flash, three second
pause
Simulated Resistive
Device Harness out
of specification.
Eight-one flash, three
second pause
Simulated Resistive
Device Harness
specification check.
Thermal well
sensor damaged or
unplugged
Eight-three flash, three
second pause
Gas valve
electronics fault
detected
LED Status Control Status
Service
Procedure
Probable Cause
Pilot valve stuck in open position.
Replace gas control,
page 26
1. Simulated resistive device out of specification.
2. Resettable thermal switch open.
1. Page 28
2. Page 29
1. Simulated resistive device out of specification.
2. Resettable thermal switch open.
1. Page 28
2. Page 29
1. Damage to thermal well wire.
2. Thermal well sensor resistance out of range. 1 & 2. Replace gas
control, page 26
1. Control needs to be reset.
2. Control is wet or physically damaged.
1. Interrupt power
supply
2. Replace gas control,
page 26
Eight-four flash, three
second pause Gas valve fault
detected. 1. Control needs to be reset.
2. Control is wet or physically damaged.
1. Interrupt power
supply
2. Replace gas control,
page 26
Troubleshooting
Six-three flash, three
second pause
Pilot flame
extinguished.
System auto resets.
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.
6. Gas pressure is out of specification.
1-4. Page 16
5. Refer to installation
manual
Page 13
Six-two flash, three
second pause
Pressure switch or
blower temp switch
opened during
burner operation.
System auto resets.
1. Check vent or vent
tables
2 & 3. Page 20
4. Refer to venting
section of
installation manual
5. Page 22
6 & 7. Page 23
1. Vent blockage or improper vent configuration.
2. Pressure switch tubing kinked or blocked.
3. Faulty pressure switch.
4. Vent termination being affected by wind.
5. Blower not spinning up to speed.
6. Blower temp or exhaust temp too high.
7. Faulty blower temperature switch.
Six-one flash, three
second pause Failed to light pilot.
System auto resets.
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.
1-4. Page 16
13