How to Keep My Air Conditioner from Freezing Up

Des Moines has been experiencing record heat this summer. While jumping into a pool of ice may sound appealing to escape the heat, you can cool off much more efficiently by keeping your air conditioner from freezing up.

How to Fix a Frozen Air Conditioner

Step 1: Turn off the air conditioner

Once you’ve identified your air conditioner coils have frozen, the first thing to do to fix it is to shut off the A/C. Turning your air conditioner off prevents wasted energy costs and minimizes potential damage to the compressor.

Step 2: Wait for the ice to melt

Unfortunately, defrosting your air conditioner requires a little patience; however, there are ways you can speed up the melting process. One way to thaw the A/C quicker is to use a blow dryer on the evaporator coil. You can also turn on the air conditioner fan without running the compressor so the ice melts faster.

Step 3: Clear the drain pan

While you’re waiting for the ice to melt, make sure to check the condensate drain for any obstructions. Clear away any blockages from the drain and ensure the drain pan is empty once the ice melts before turning the A/C back on.

Step 4: Turn on the Air Conditioner

Turn the air conditioner back on and your home should begin cooling immediately! If it doesn’t start cooling, call a professional air conditioner technician.

What Causes the Air Conditioner to Ice Over?

Even if you’ve never experienced an air conditioner that ices over, it’s important to understand what causes this problem so you can prevent or remedy it in the future.

A frozen air conditioner can be caused by any of the following problems:

  • Dirty air filter: This is the number-one cause of an icy air conditioner. Low airflow prevents the coil from receiving an adequate amount of warm, humid air. Please change the air filter regularly to prevent the coil from freezing up.
  • Low refrigerant levels: If your refrigerant levels are too low due to a leak or improper charge, the evaporator coil can become too cold and freeze. Be sure to call a professional to repair or recharge the system.ice
  • Closed registers: Some homeowners shut supply registers in rooms that aren’t used often to save money and energy. Closing too many registers can actually cost you more in the long run by causing your air conditioner to freeze up. A good rule to follow is to keep 75% of your home’s supply registers open to prevent the A/C from icing over.
  • Thermostat issues: If your air conditioner is running more than it needs to, it could freeze and indicate a problem with the thermostat. Have an HVAC professional check the thermostat for repair or replacement.
  • Poor drainage: With how humid the summers are in Iowa, that hot, moist air leaves behind water vapor as it’s cooled by the air conditioner. Normally the water drips into a pan and through a floor drain, but if there is a blockage in the drain that water backs up and freezes on the evaporator coil. Keep the drainpipe clear and check it regularly when it’s really hot outside to make sure it is draining properly.

How You Can Prevent Your Air Conditioner from Freezing Up

The most important thing homeowners can do to prevent the air conditioner from freezing up is to change the air filter regularly. Make sure to keep the supply vents open and inspect the condensate drain periodically to ensure condensation is draining properly. You may also want a professional HVAC service technician to check the thermostat and refrigerant level if your A/C starts to get icy.