Troubleshooting Central Air Conditioners

Central air conditioners will need some professional maintenance, but there are many minor problems that you can easily fix yourself. If your central A/C unit isn’t working properly, locate the problem you are experiencing on this chart to determine if a service call from a professional air conditioning contractor is necessary.

CENTRAL AIR CONDITIONER TROUBLESHOOTING CHART
ProblemPossible causeSolutions
Condenser doesn’t run1. No power.1. Check for blown fuses or tripped circuit breakers at main entrance panel or at separate entrance panel; restore circuit.
2. Thermostat set too high2. Lower thermostat setting 5°.
3. Motor faulty.3. Call a professional.
4. Compressor faulty.4. Call a professional.
Uneven cooling1. Distribution system out of balance.1. Adjust register dampers or call a professional.
Unit doesn’t cool1. Thermostat set too high.1. Lower thermostat setting 5°.
2. Condenser dirty.2. Clean condenser coil and fins; if necessary, straighten fins or call a professional.
3. Condenser unit blocked.3. Remove debris blocking condenser; cut down weeds, grass, and vines or call a professional.
4. Evaporator dirty.4. Clean evaporator or call a professional.
5. Compressor faulty.5. Call a professional.
6. Not enough refrigerant in system.6. Call a professional.
Condenser unit turns on and off repeatedly1. Condenser dirty.1. Clean condenser coil and fins or call a professional.
2. Condenser unit blocked.2. Remove debris blocking condenser; cut down weeds, grass, and vines.
3. Evaporator dirty.3. Clean evaporator or call a professional.
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