Why Does My Air Conditioner Freeze Up?

One of the more common and frustrating things that can happen to your Air Conditioning Unit is a freeze up. This is exactly what it sounds like, when a layer of ice forms on the outside of your AC unit. Whether you have a window unit or a central air system the causes and effects of this, as well as the solutions, are all the same. The ice build up on your AC unit creates an inability to cool effectively, and also puts stress on the compressor which in time can lead to a costly repair or the need for a replacement compressor.

Let’s take a look at a few reasons why your Air Conditioner might be freezing up.

Insufficient Air Flow: Anything that restricts the air flow in your unit will cause the system’s evaporator coil to freeze up. There are a few reasons that air might not be flowing efficiently. The most common problem is a dirty air filter, which is pretty self explanatory, a dirty air filter means less air flow. If you are running your AC unit continuously, we recommend replacing or cleaning the air filter once a month. Other problems include blocked or closed ducts and vents, a faulty fan and dirt on the evaporator coils. Evaporator coils need regular cleaning, we recommend once a season.

Low on Freon: Another thing that causes an AC freeze up is low refrigerant or Freon. This causes a drop in pressure in the evaporator coil which then allows moisture in the air to accumulate and freeze on the coil. Low refrigerant or Freon is caused by a leak. If the reason your unit is freezing up is because of low Freon, you will want to contact a HVAC contractor to repair the unit for you. This includes finding and repairing the leak and refilling your refrigerant levels.

Outdoor Temperature: Air conditioners are designed to run in a specific temperature range. Most of them will not run well below 60° F. Often a freeze up occurs because night-time temperatures are dropping too low for the unit to function properly, the pressure inside the system will drop and will cause your freeze up.

Remember that whether you have a window unit or a central air system, the reasons for a freeze up don’t change and the solutions are the same as well. Contact Us and we can see about finding the solution to your freeze up problem.

Contact us to schedule a routine service call for your Air Conditioning unit.


Ballard Natural Gas Services is proud to offer services to Seattle, Shoreline, West Seattle, Capitol Hill, Lake Forest Park, Richmond Beach, Bellevue, Mercer Island, Edmonds, Mountlake Terrace and the surrounding communities. Call us at 206-784-8101 or request service online today!

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Contact the experts at Answer Heating & Cooling.

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