A melting ice cube on a blue surface representing why air conditioning units freeze.

Why Do Air Conditioners Freeze?

An air conditioner unit has the potential to freeze. It’s a strange sight, especially in the middle of a hot summer day, but that’s when it’s most likely to happen. A frozen air conditioner is a common problem and can sometimes be fixed easily. Other times, however, you’ll need an air conditioner repair technician to take a look at it.

Why does it freeze in the first place?

First things first: why is it frozen? There are 2 possible scenarios in which your air conditioner can freeze up.

ice

  1. On a hot summer day, the sun is constantly beating down on your home, heating it up. To counter the heat, the air conditioner kicks into high gear (or you set it into high gear). As it is cooling your home, it may begin to build up condensation on the evaporator coil. The evaporator coil is supposed to be kept warm internally, but without this heat, the temperatures could drop below 32ºF and freeze the condensation, giving you a blockage. This blockage, in turn, causes more water to freeze, intensifying the problem.
  2. The other possible cause, and most common cause, is that your AC is simply low on refrigerant or Freon. It could be that you have a refrigerant leak, which should be repaired as soon as possible to prevent future freezes and other potential problems. This refrigerant is responsible for cooling and dehumidifying your air. Without it, your AC will not cool your home. It will just blow air.

What should I do with my frozen air conditioner?

The first thing you should do is turn the air conditioner off and let it defrost. Since it’s a warm day, it shouldn’t take more than an hour or 2 to fully defrost. It is not safe for the unit to keep it running while frozen. It won’t be very efficient, but more importantly you may damage the compressor. Replacing the compressor is the most expensive repair you can do to your air conditioner. All air conditioner unit owners should do the following, whether it’s frozen because of scenario 1 or 2:

  • Clean your filter. Replace if necessary.
  • Make sure your vents are clear. If there’s no breathing room, the heat will not prevent these freezings.
  • After turning it on again, check blower motors to ensure they are working properly. If it’s blowing and not making any strange noises, it is fine. (See Why is my Air Conditioner so Loud? for more on noises)

If your problem was a dirty air filter, or you found some dirt and debris around the system that could have been the culprit, then your problem may be fixed.

If your refrigerant is low, be sure to call an HVAC technician to come take a look at it. In some cases, a technician will have to clear out the air flow issues so as to not damage the system.

Final Thoughts

Be sure to check your fan as well. Listen for strange sounds, look out for puddles from melted ice, and pay attention to the smells. If anything is wrong with your air conditioner and you need an HVAC technician in PA to take a look at it, then contact us and we’ll come out to fix it.

Comments for this post are closed.