Why does your AC freeze over

A frozen AC in the middle of a Texas summer? We know — it sounds impossible. But frozen air conditioners are actually a pretty common occurrence, and they happen more the hotter it gets. Before you call us crazy, the HVAC experts from Service Wizard are here to explain why AC systems freeze and tell you exactly what to do if you find ice on yours.

Why Do Air Conditioners Freeze?

Although ice in the middle of summer seems to defy science, it’s actually pretty simple. Your AC’s coils contain refrigerant that absorbs heat from inside and deposits it outside, cooling the air in your home. During this process, the change of temperature pulls moisture out of the air and forms condensation on the coils that drips off into the drain pan.

When dust, dirt and other debris gather on the coils, the condensation sticks to the debris rather than dripping away. The water that collects then slows the heat transfer between the air and the coils, causing the refrigerant to get colder and colder. This causes the water to freeze, which completely blocks the cooling process. When your AC is frozen, you’ll feel that your AC is blowing warm air as a result.

Preventing a Frozen AC

Because frozen air conditioners are a pretty common problem, you may be wondering if there’s anything you can do to keep your AC from freezing. The best way to prevent this problem is by regularly changing your air filter. While it’s an easily forgettable task, changing your air filter every one to three months will help keep dust out of your HVAC system and prevent debris buildup.

How to Fix a Frozen AC

If you find ice on your AC, don’t panic — it’s easy to fix the problem on your own with a little patience! Follow these steps to thaw your frozen air conditioner:

Immediately go to your thermostat and change the setting to OFF.
Change the fan setting to ON. This will circulate warm air through the HVAC system and thaw the ice faster.
Wait for the ice to melt. This could take a few hours or even most of the day, so consider going to the pool, seeing a movie or even visiting a friend to avoid sitting in a hot, uncomfortable house.
Once all of the ice is melted and the coils are completely dry, you can turn your thermostat to COOL and your fan to AUTO.

Once you’ve completed these steps, you should notice the change of temperature within the hour. Periodically hold your hand to a vent to feel for cool air if you’re unsure.

AC Freezing Up? Call a Professional

Fixing a frozen air conditioner isn’t an easy DIY task, but it’s not something you should have to do more than once. If your AC keeps freezing up, there’s probably a more serious problem with the system, such as a refrigerant leak. Call a professional HVAC company like Service Wizard for AC repairs if your AC freezes more than once or twice.