– 13 –
Symptom
Cause
Remedy
A. If blower does not
operate.
B. If there is no voltage at
ignition control (RE-02)
input terminal and the
fan is enabled.
C. If the ignition control
(RE-02) goes into safety
shutdown (lockout).
1. Low or no voltage.
2. Fuse(s) blown.
3. Customer interlock not closed or
connected.
4. Fan is disabled.
5. Time clock, night setback
thermostat, or
fi
eld installed
controls open.
6. Freeze protection tripped. (low
discharge temperature)
7. Damper motor not operating, its
end switch not making, or the
damper is binding.
8. Overload Protection on motor
starter tripped.
9. Belts loose or broken.
10. Bearings seized.
11. Motor may be burned or
incorrectly wired.
12. Blower motor overheating.
13. DO-1 on UC-01 not energized.
14. Door switch open.
1. Heat mode is disabled.
2. Auxiliary switch on starter not
closed (ST-01).
3. Air
fl
ow switches open.
4. Outside air temperature higher
than Heating Economizer
Setpoint.
5. High temperature limit thermostat
open.
6. High-low gas pressure switch
open. (If applicable)
7. Field purge timer open.
(If
applicable)
8. DO-2 on UC-01 not energized.
1. See technical cut sheet on
ignition control.
1. Check power source.
2. Check and replace.
3. Close or connect customer interlock.
4. Enable the fan.
5. Check time clock, night setback
thermostat and
fi
eld installed
controls for proper settings.
6. Reset freeze stat by interrupting
power. Check for proper setting
and burner operation.
7. Check for power at damper
motor and that end switch has
been wired correctly to the N.O.
(normally open) contact. Check
that the linkage is clear and not
binding.
8. Push reset button on starter and
check amps.
9. Turn power off and check belts.
10. Check and replace.
11. Turn power off and check motor
and wiring.
12. Check burner
fi
ring rate.
13. See Digital Control System User
Manual.
14. Close door. Check and/or replace.
1. Enable the heating mode.
2. Check auxiliary circuit wiring and
contact.
3. Adjust the air
fl
ow and external
static pressure to match the
rating plate (Do not adjust switch
setpoint).
4. Check stat for proper setting.
5. Reset control and correct prob-
lem before restarting.
6. Check gas pressure and reset
switch.
7. Check for power or replace if
necessary.
8. See Digital Control System User
Manual.
1. Determine the cause of (lockout).
Recycle power.
SECTION VII - TROUBLESHOOTING
continued
Fan and Heat Mode
(Refer to Digital Control System User Manual for additional troubleshooting suggestions)
