Bradford White TW4-75S-76B-3X - Manual (Page 13)

Short flash, once every
four seconds
“Heartbeat”, alternates
bright/dim
Thermostat calling
for heat (no fault).
Short flash once every
3 second
Weak pilot signal
on last call for
heat.
Two flash, three
second pause
Pressure switch
not working-
closed position.
Three flash, three
second pause
Pressure switch
or blower temp.
switch not working
-open position.
Four flash, three
second pause
Excessive tank
temperature.
System must be
reset.
Five flash, three
second pause
Undesired-false
pilot flame
present.
Troubleshooting
LED Status
Stand-by mode,
Waiting for call for
heat (no fault).
Control
Status
Service
Procedure
Probable Cause
Temperature demand is satisfied
Normal operation.
Adjust thermostat to
temp level
Tank temperature below set point of thermostat.
Normal operation.
Adjust thermostat to
temp level
1. Unstable pilot.
2. Pilot tube block or restricted.
3. Oxidation build up on pilot electrode.
4. Wire damage to pilot assembly or bad
connection at gas valve.
1. Page 15
2-4. Page 17
1. Pressure switch tubing kinked or blocked.
2. Blocked pressure tap on switch or blower.
3. Faulty pressure switch.
Page 18
1. Vent blockage or improper vent configuration.
2. Pressure switch tubing kinked or blocked.
3. Faulty pressure switch.
4. Blower not spinning up to speed.
5. Blower temp or exhaust temp too high
6. Faulty blower temperature switch.
1. Check vent or vent tables.
2 & 3 Page 18
4. Page 20
5 & 6 Page 22
1. Thermal well sensor out of calibration.
2. Faulty gas control.
3. Pluming leak
1. Page 24
2. Replace gas control,
page 24
1. Pilot valve stuck in open position.
Replace gas control,
page 24
None, control LED not
on or flashing
No electrical
power
Control power switch in “OFF” position.
Supply voltage interrupted.
Turn power on
Page 13
Observe green LED indicator on
Electronic 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.
Green LED
Indicator
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Page 13
Green LED
Indicator