Bradford White TTW 75 SERIES Service Manual page 13

LED Status
Failed to light
Six-one flash, three pilot.
second pause System auto
resets.
Pressure switch
or blower temp
switch opened
Six-two flash, three
during burner
second pause
operation.
System auto
resets.
Pilot flame
Six-three flash, three extinguished.
second pause System auto
resets.
Undesired-false
pilot flame
Six-four flash, three
sensed.
second pause
System auto
resets.
Simulated
Seven flash, three Resistive Device
second pause Harness out of
specification.
Simulated
Resistive Device
Eight-one flash, three
Harness
second pause
specification
check.
Thermal well
sensor damaged
or unplugged
Eight-three flash, three
second pause
Gas valve
electronics fault
detected
Eight-four flash, three Gas valve fault
second pause detected.
Control
Status
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. 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.
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.
Pilot valve stuck in open position.
Simulated resistive device out of specification.
Simulated resistive device out of specification.
1. Damage to thermal well wire.
2. Thermal well sensor resistance out of range.
1. Control needs to be reset.
2. Control is wet or physically damaged.
1. Control needs to be reset.
2. Control is wet or physically damaged.
Probable Cause
Troubleshooting
Service
Procedure
1. Page 14
2-4. Page 16
1. Check vent or vent tables.
2 & 3 Page 17
4. Refer to venting section of
installation manual
5. Page 19
6 & 7 Page 21
1. Page 14
2-4. Page 16
5. Refer to installation manual
Replace gas control,
page 25
Page 27
Page 27
Page 23
1. Interrupt power supply
2. Replace gas control,
page 25
1. Interrupt power supply
2. Replace gas control,
page 25
Page 13
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