12
UPV75 Series - Troubleshooting
Observe green LED indicator on electronic
gas control. Status flash codes are
displayed with a three second pause before
repeating. Check and repair the system as
noted in the troubleshooting table below.
LED Status
Control Status
Probable Cause
Service Procedure
None, control
LED not on or
flashing
No electrical power Control power switch in “OFF” position.
Supply voltage interrupted.
Turn power on.
Short flash, once
every four
seconds
Stand-by mode,
waiting for call for
heat (no fault).
Temperature demand is satisfied.
Normal operation. Adjust
thermostat to temp level.
Alternates
bright/dim
(heartbeat)
Thermostat calling
for heat (no fault).
Tank temperature below set point of
thermostat.
Normal operation. Adjust
thermostat to temp level.
Short flash once
per second
Weak pilot signal on
last call for heat.
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.
Page 16.
Two flash, three
second pause
Pressure switch not
working- closed
position.
1.
Pressure switch tubing kinked or
blocked.
2.
Blocked pressure tap on switch or
blower.
3.
Faulty pressure switch.
Page 18.
Three flash, three
second pause
Pressure switch or
blower temp. switch
not working -open
position.
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 24
Four flash, three
second pause
Excessive tank
temperature.
System must be
reset.
1.
Temperature sensor out of
calibration.
2.
Faulty gas control.
3.
Plumbing leak.
1 & 2. Replace gas
control, page 28.
Five flash, three
second pause
Undesired-false pilot
flame present.
1. Pilot valve stuck in open position.
Replace gas control,
page 28.
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