To fix an air conditioner that continually freezes or ices up, check things like the air filter, refrigerant level, blower motor, evaporator coil and ductwork. If the cause is not immediately clear, the homeowner should contact a local heating, ventilating and air conditioning, or HVAC, professional.
An air conditioning unit freezes up because the evaporator coil is being cooled more than it should be. Doing a few quick checks can help determine what the root cause is, and define an easy fix.
- Check the air filter
- Check the refrigerant level
- Check the blower motor
- Check the evaporator coil
- Check the duct work
A clogged air filter causes the system's temperature to drop because there is not enough air flow through the conditioner. Replace the filter every 2 to 3 months.
Normally, Freon levels stay the same. If there is a leak, however, the refrigerant level will drop. If the pressure drops too low, it causes the unit to ice up.
If the unit is running but the indoor system is not, that indicates the motor blower may not be working correctly. This lack of airflow may cause the system to freeze.
Lack of airflow can also be caused by a dirty evaporator coil. It causes a temperature drop and icing up of the system.
This involves going into the attic and inspecting the duct work for leaks, bends or disconnected sections. A blockage in the duct decreases airflow, resulting in freezing.