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Short flash, once every
four seconds
“Heartbeat”, alternates
bright/dim
Thermostat calling
for heat (no fault).
Short flash once per
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.
T
roubleshooting
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 14
2-4. Page 16
1. Pressure switch tubing kinked or blocked.
2. Blocked pressure tap on switch or blower.
3. Faulty pressure switch.
Page 17
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.
7. Intake vent length exceeds exhaust vent length.
1. Check vent or vent tables.
2 & 3 Page 17
4. Page 21
5 & 6 Page 23
1. Thermal well sensor out of calibration.
2. Faulty gas control.
3. Plumbing leak
1. Page 25
2. Replace gas control,
page 27
1. Pilot valve stuck in open position.
Replace gas control,
page 27
None, control LED not
on or flashing
No electrical
power
Control power switch in “OFF” position.
Supply voltage interrupted.
Turn power on
Page 12
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.
G
reen LED
Indicator
PDX Series
12