115
Compressor Troubleshooting Chart
Problem
Potential Cause
Corrective Action
Compressor
will not start
Shorted or broken wires
Use a multi-meter to check the compressor wiring
harness for an open or short circuit.
Locked rotor
Check continuity of the compressor. Replace if failed.
Low voltage
Test voltage.
Internal failure
If no other failure is present, there is an internal failure.
Replace the compressor.
Compressor
runs
intermittently
Shorted or broken wires
Check the compressor wiring harness for an open or
short circuit.
Loose connections
Secure connections.
Shorted or grounded compressor Check for continuity from the compressor terminals to
ground.
There should be no continuity.
Overcharge of refrigerant
Recover part of the refrigerant.
Dirty outdoor coil
Clean the outdoor coil.
Incorrect thermostat location
Relocate thermostat.
Electronic Expansion Valve (EEV) Verify the correct expansion valve is installed.
Hot Gas Reheat Valve
Refer to
“Hot Gas Reheat Valve (HG-1/HG-2)” on
Faulty reversing valve
Test reversing valve.
Defrost control
Test defrost control.
Compressor
cycles on
overload
Shortage of refrigerant
Test for leak. Recharge.
Restricted discharge line
Repair or replace as needed.
Non-condensables in system
Recover the charge, evacuate the system. Recharge
the system.
Recirculation of condensing air
Remove airflow obstruction.
Electronic Expansion Valve (EEV) Make sure the expansion valve is operating properly.
Compressor
making
abnormal
noise
Overcharge of refrigerant
Recover part of the refrigerant.
Loose hardware
Tighten the mounting bolts.
Internal failure
If no other failure is present, replace the compressor.
Liquid in compressor head
“Superheat and Subcooling” on page 118
and EEV position.
Low suction
pressure
Low charge
“Superheat and Subcooling” on page 118
Restricted discharge line, drier, or
reversing valve
Repair as needed.
Compressor
oil issues
Low oil
If sight glass is available, check oil level. Add oil.
If there is an oil level sensor. Refer to
Imbalance of refrigerant
“Superheat and Subcooling” on page 118
Compressor running too slow for a
long period of time
Adjust compressor speed.