How to Start a Home Air Compressor If it Is Low on Freon?

Test for other problems. Low freon may not be the cause of the air conditioning system not starting. Check wiring and connectors first. Low voltage at the compressor will prevent the unit from starting. The oil level may be low, the delay timer or capacitors may be faulty and the contactor may fail. Install replacement parts, if necessary.

Check the system for leaks. An HVAC system low on refrigerant has a low-pressure safety valve that will not open if the pressure drops to a certain level. Check for a loose valve or a corroded pipe as this can cause a freon leak. Tighten the valve, replace the pipe or replace the freon, if necessary.

Call a licensed technician if you are unable to repair the unit yourself. Do not continue to attempt to run your air conditioner if you suspect it is low on freon as a 10-percent drop in the freon level causes higher energy demands from the system and abnormal wear and tear.