When your central air conditioner runs but doesn’t cool, the problem could be caused by something as simple as bad thermostat settings. If the thermostat is set to run the fan constantly but the temperature setting isn’t low enough to initiate cooling, then you can fix the cooling problem by adjusting the thermostat settings. If the thermostat is faulty and won’t signal the air conditioner to start cooling, then you’ll need to replace the thermostat.
If thermostat settings are okay, then the outside compressor and condenser unit may not be working. Check to see if the condenser fan and compressor are running. If not, check the house circuit breakers for the outside unit. Resetting the house circuit breaker may restore cooling. A bad capacitor can prevent the compressor and condenser fan from running. Many AC systems use 1 dual capacitor to help start the compressor and condenser fan. If the capacitor is bad, you’ll need to have it replaced.
If the compressor and condenser fan both run, then lack of refrigerant or a bad compressor may be preventing the air conditioner from cooling.
Several other problems such as a wiring failure or a bad compressor fan motor can prevent the AC from cooling. If you’re not able to diagnose and fix a cooling failure yourself, have a service technician repair your air conditioner.
