If your air conditioner is frozen or, more accurately, you have a frozen AC coil, turn it off immediately. It's not cooling your house. Shutting off the unit helps homeowners avoid energy waste. It also protects the compressor (the most costly part of your cooling system) from damage. But what causes an air conditioner to freeze?
Signs of a frozen air conditioning coil
- The AC is running but the indoor temperature is still rising -- Once freezing begins, ice grows upward on the cold coil, blocking air from passing through and into your home.
- You have an overflowing drip pan -- Ice from the frozen coil may be blocking the drain hole. To find the drip pan for your central AC, locate the cold coil inside the ductwork near your furnace. The drip pan is beneath it, ready to catch condensation from the AC. Water then flows into the drain pipe, directing it into a floor drain.
What Causes an Air Conditioner to Freeze
- Clogged air filter restricting airflow -- Check the filter and replace it if it is dirty.
- Blocked registers -- Check your room air registers and make sure they’re not obstructed by furniture, rugs or drapes. Without a supply of warm air from your house, condensed water will freeze on the air conditioning coil before it can drain properly.
- Slow or no fan -- Freezing can occur if the fan is motionless or moving very slowly when the AC system is operating. Your home comfort contractor may be able to adjust the fan speed.
- Malfunctioning thermostat -- If it's not reading the temperature correctly, the AC may run needlessly (throughout a cool night, for example), risking air conditioner freeze-up.
- Refrigerant leak -- Without sufficient refrigerant pressure, too little heat is absorbed to keep the coil warm. Your local HVAC contractor can locate leaks, make repairs, and charge your air conditioner with the proper amount of refrigerant.
Air conditioning problems? Wondering what causes an air conditioner to freeze? Contact the experts at Comfort24-7. Visit us online or give us a call. We're proud to serve homeowners in the Chicago area, as well as Northwest Indiana and Southwest Michigan.