SYMPTOM
Compressor and outdoor fan will not start
Compressor will not start but condenser fan
runs
Compressor cycles
(other than normally satisfying thermostat)
Compressor operates continuously
Excessive head pressure
Head pressure too low
Excessive suction pressure
Suction pressure too low
Table 5 - Troubleshooting Chart
CAUSE
Power failure
Loss of Charge Switch Open
Fuse blown or circuit breaker tripped
Defective thermostat, contactor, transformer, or
control relay
Insufficient line voltage
Incorrect or faulty wiring
Thermostat setting too low/too high
Faulty wiring or circuit
Loose connections in compressor
Compressor motor burned out, seized, or
internal overload open
Defective run/start capacitor, overload start relay
Low input voltage
Refrigerant overcharge or undercharge
Loss of Charge Switch Open
Defective compressor
Insufficient line voltage
Blocked outdoor coil
Defective run/start capacitor, overload or start relay
Defective thermostat
Faulty outdoor fan motor or capacitor
Restriction in refrigerant system
Dirty air filter
Unit undersized for load
Thermostat temperature set too low
Low refrigerant charge
Leaking valves in compressor
Frosted outdoor coil with incorrect defrost operation
(heating)
Air in system
Outdoor coil dirty or restricted
Dirty air filter
Dirty indoor or outdoor coil
Refrigerant overcharged
Air in system
Indoor or outdoor air restricted or air short-cycling
Low refrigerant charge
Compressor valves leaking
Restriction in liquid tube
High Heat load
Compressor valves leaking
Refrigerant overcharged
Dirty air filter
Low refrigerant charge
Metering device or low side restricted
Insufficient coil airflow
Temperature too low in conditioned area
Outdoor ambient below 55°F (13°C)
Filter drier restricted
Compressor runs but outdoor fan does not Normally closed contacts on defrost board open
REMEDY
Call power company
Evaluate unit for possible refrigerant leak
Replace fuse or reset circuit breaker
Replace component
Determine cause and correct
Check wiring diagram and rewire correctly
Reset thermostat setting
Check wiring and repair or replace
Determine cause
Replace compressor
Determine cause and replace
Determine cause and correct
Recover refrigerant, evacuate system, and re-
charge to capacities shown on rating plate
Evaluate unit for possible refrigerant leak
Replace and determine cause
Determine cause and correct
Determine cause and correct
Determine cause and replace
Replace thermostat
Replace
Locate restriction and remove
Replace filter
Decrease load or increase unit size
Reset thermostat setting
Locate leak, repair, and recharge
Replace compressor
Check defrost time settings, Reset as neces-
sary. Check defrost temperature switch.
Replace as necessary.
Recover refrigerant, evacuate system, and re-
charge
Clean coil or remove restriction
Replace filter
Clean coil
Recover excess refrigerant
Recover refrigerant, evacuate system, and re-
charge
Determine cause and correct
Check for leaks, repair and recharge
Remove restriction
Remove restriction
Check for source and eliminate
Replace compressor
Recover excess refrigerant
Replace filter
Check for leaks, repair and recharge
Remove source of restriction
Check filter-replace if necessary
Reset thermostat setting
Install low-ambient kit
Replace
Check condition of relay on board.
Replace board if necessary.
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