Causes Of Air Conditioner Freezing

18 May 2021
 Categories: , Blog


One reason why your air conditioner is not keeping your home cool is that it is freezing up. If you were to examine the inside of your unit, you may see frost on the evaporator coil or suction lines. Your air conditioner will otherwise run and sound fine. However, you will feel only a little cool air coming out of your unit. Here are some common causes of frozen air conditioners and how an air conditioner technician can fix them.

Your Unit Has Low Refrigerant Levels

Low refrigerant levels are a common cause of a frozen air conditioner. When the refrigerant is low, it disrupts the pressure cycle and timing. The result is a severe drop in the evaporator coil temperature. Humidity makes this issue worse because it adds more moisture accumulation. If your refrigerant is low, you likely have a leak. Air conditioner systems are sealed and don't use up the refrigerant.

Your Unit Has Poor Airflow

The evaporator coils rely on a steady flow of warm air exiting the home. This air keeps the coils and lines from becoming too cold and freezing. However, if your unit doesn't have good airflow, then the evaporator coil and lines will freeze. Low airflow can be closed by blocked filters or a broken fan motor.

Your Unit Has a Clogged Drain Line

You've likely noticed water dripping from your unit from time to time. Or, the area under the unit may be wet, especially on humid days. Your air conditioning unit removes moisture as well as heat from your home. Normally, the water drains harmlessly out of the air conditioner. If the drain is blocked, it increases the moisture inside the unit and contributes to freezing. Periodically check the drain to ensure it is not blocked.

Your Unit Has a Lot of Dust Accumulation

If you don't use sufficient filtering, you increase the chance of dust accumulation inside your unit. Add this dust to moisture on the coils, and you have a thermal blanket. When that process happens, the cold is trapped inside the coil, and the lines freeze. Have your air conditioning unit serviced and cleaned regularly to keep internal dust levels low.

You may be able to do some fixes yourself. You can change the filter and check to ensure that the air vents are open. If you suspect your air conditioner has frozen over, turn off the unit. There's no use in running it and wasting electricity when it won't produce cold air. Then, call an AC repair technician as soon as possible.