Blue Mountain Plumbing, Heating & Cooling

Why Do AC Units Freeze Up?

There are a couple of main reasons why AC units freeze up. The first is due to airflow issues. By “airflow” we are referring to the air flowing over the evaporator coil (the tubes that have cold liquid refrigerant running through them). When your air conditioning unit experiences insufficient airflow over the coils, it can get too cold and can be the cause for a broken air conditioner. When this happens, condensation and moisture will build up on the coils causing them to quickly ice up.

Why Do AC Units Freeze Up? Common causes for insufficient airflow may include:

• Dirty air filter (during the summer the filter should be changed once a month)
• Closed air supply vents
• Return grills covered by drapes or obscured by furniture
• Dirt buildup on the evaporator coil
•  Improperly sized ductwork
•  Bad blower motor

Another reason why an air conditioning unit may freeze up is due to low refrigerant or a refrigerant leak. It is the refrigerant that collects the heat in your home and moves it outside. When an air conditioner is low on refrigerant or it is charged incorrectly, the coils containing the refrigerant get too cold which can cause ice to build up on the coils. The problem can grow quickly when the air is humid or the coils are dirty and be the cause for a broken air conditioner.

So, why do AC units freeze up? As you can see there are a number of reasons. If your air conditioner coils are experiencing a buildup of ice, the first thing you should do to prevent any extended damage is turn off the air conditioner. Next, set your thermostat’s fan setting to the “on” position to thaw the ice in the inside unit. Once those steps have been taken, call Blue Mountain Plumbing, Heating, and Cooling to conduct an inspection to figure out why the AC unit froze up and determine the exact cause of the ice buildup.

To schedule an appointment for regular service, preventative maintenance and care, or air conditioning service or repair unit please call us today at (720) 839-4015. Additionally, Blue Mountain is available to provide emergency service 24 hours a day, 7 days a week.