Installation Manual
17
TROUBLESHOOTING INFORMATION: UNITARY DIAGNOSTIC CODES
Digit3 Digit2 Digit 1
• Run time for last 4 cycles is less
than 3 minutes each.
• Compressor protector has not tripped.
• Low pressure and high pressure
switches are closed.
• Integrated control module
diagnostic/status LED display shows
the indicated code.
BLANK
0 3 • Short Cycling
• Intermittent
thermostat demand.
• Faulty compressor
relay.
• Check thermostat
and thermostat wiring;
repair/ replace as
needed.
• Check compressor
relay operation;
replace control as
needed.
• Turn power OFF prior
to repair.
• Fault will clear after 4
consecutive normal
cycles.
• Fault may be cleared
by cycling 24VAC to
control.
• Replace with correct
replacement part(s).
• Minimum
compressor run time is
changed from 30
seconds to 3 minutes.
• Compressor and outdoor fun are off.
• Compressor protector trips four
consecutive times.
• Average run time between trips is
less than 1 5 seconds.
• Integrated control module
diagnostic/status LED display shows
the indicated code.
BLANK
0 4 • Locked Rotor
• Compressor
bearings are seized.
• Failed compressor
run capacitor.
• Faulty run capacitor
wiring.
• Low line voltage.
• Check compressor
operation; repair/
replace as needed.
• Check run capacitor;
replace as needed.
• Check wiring;
repair/replace as
needed.
• Verify line voltage is
within range on rating
plate; contact local
utility is out of range.
• Turn power OFF prior
to repair.
• Must clear fault by
cycling 24V AC to
control.
• Replace with correct
replacement part(s).
• Compressor and outdoor fun are off
for greater than 4 hours.
• Low pressure and high pressure
switches are closed.
• Integrated control module
diagnostic/status LED display shows
the indicated code.
BLANK
0 5 • Open Circuit
• Power is
disconnected.
• Failed compressor
protector.
• Compressor not
properly wired to
control.
• Check circuit break
ers and fuses .
• Check wiring to unit;
repair/ replace as
needed.
• Check compressor
repair/replace as
needed
• Check compressor
wiring; repair/ replace
as
needed.
• Turn power OFF
prior to repair.
• Fault will clear after 1
normal cycle.
• Fault may be cleared
by cycling 24V AC to
control.
• Replace with correct
replacement part(s).
• Compressor and outdoor fun are off.
• Low pressure and high pressure
switches are closed.
• Integrated control module
diagnostic/status LED display shows
the indicated code.
BLANK
0 6 • Open Start Circuit
• Compressor start
winding is open.
• Failed compressor
run capacitor.
• Faulty run capacitor
wiring.
• Compressor not
properly wired to
control.
• Faulty compressor
wiring.
• Check compressor
repair/replace as
needed.
• Check run capacitor;
replace as needed.
• Check wiring;
repair/replace as
needed.
• Turn power OFF prior
to repair.
• Fault will clear after 1
normal cycle.
• Fault may be cleared
by cycling 24V AC to
control.
• Replace will correct
replacement part(s).
UNITARY DIAGNOSTIC CODES
Symptoms
of
Abnormal Operation
Diagnostic/Status
LED Display Codes
Fault Description
Possible
Causes
Corrective Actions
Notes &
Cautions










