What Causes An A/C To Freeze Up? | R. A. Styron | Chesapeake A/C Specialists

Frozen air conditioners are one of the chief complaints at the beginning of every summer, leaving many Hampton Roads residents with no relief from the summer heat. A frozen air conditioner doesn’t necessarily mean you have a serious problem on your hands. If you find yourself in this situation solving the issue can sometimes be very simple.

As soon as you notice your system freezing up you should always shut the system down immediately. No repairs, professional or DIY, can be made to a frozen system. If you continue to run the air conditioner your system will not only continue forming ice but may lead to additional repairs as well. If your system is heavily covered in ice you may even want to switch you thermostat into heat mode to speed up the thawing process.

During the thawing process be sure to keep an eye on the water levels in the drain pan under the system. Water not draining properly, or at all,  will lead to overflows and water damage to your system and/or home. Should you notice the water levels rising there are couple of things you can do to prevent an overflow.

  • If you have a wet/dry vac you can use that to suck up some of the water.
  • Grab a towel and bucket. Gently put the towel in the drain pan to soak up some of the water then carefully ring the access water out into the bucket.

Now that you have your system thawed out, let’s dive into the reason you are seeing the ice build-up!


This is probably the most common reason homeowners find themselves with a frozen air conditioner! Warm air pulled out of your home is pushed over the coil to prevent condensation buildup. Without sufficient airflow the coils can become in-cased in ice fairly quickly. We dive deeper into the ins and outs of a properly functioning system, here.

To confirm airflow is the issue at hand, first check your air filters. Clogged or dirty air filters reduces air flow to your system causing various issues leading to unnecessary breakdowns. Because air filters are out of sight they are often neglected becoming caked with dust and other particles restricting the air flow that your system desperately needs.

If you find yourself with a dirty or clogged air filter, change it immediately. Air filters are often cheap and easily found at most hardware stores, some grocery stores even carry them. If you are unsure how to change or which filter to purchase, we have everything you need know about filters, here.

Poor airflow could still be a problem even if you have found your filters clean. Take a look and inspect the air vents around your home. Be sure that none of them are blocked or closed off.


In addition to cooling the air in your home, air conditioners also dehumidify the air. Condensation that builds up on the coils is the water that is pulled out of the air because of the dehumidifying process. In a properly functioning system the condensation build up falls off in little droplets into the drain pan.

When coils become dirty the layer of filth prevents them from absorbing the water fast enough, beginning the freezing process. Bi-annual maintenance on your heating and a/c system along with routine changing of filters will prevent this from occurring.


Low refrigerant levels are almost as common as dirty filters. Refrigerant, also known as freon, plays a very vital role in cooling your home. Explaining exactly how freon works can get extremely “science-y” quickly. Put simply, freon has the ability to change its form from a gas to liquid quite easily. By changing it’s form, temperature, and pressure the freon is able to both release and absorb heat.

Too much or too little freon will cause your system to build up ice on the coils eventually leading to your system blowing warm air or no air at all. Low freon levels will have to be assessed and repaired by a licensed professional. The EPA highly regulates who can purchase, possess, and work with this chemical because of the effects it can have on our planet.


Blower fans are an essential part of your system. They help move cold air where it needs to be while blowing the warm air outside of your home. The functionality of your system is completely dependent on having the correct balance of air pressure and flow.

When your blower fan or motor becomes damaged or broken it will significantly change the airflow inside of your system. When that happens condensation will build up on the coils leading to icing up of the coils. In addition to the coils freezing a broken blower can cause the freon lines to freeze, as well. This can lead to even more issues with your condenser on the outside of your home.


As mentioned earlier, prior calling in any repair company make sure that your system has thawed out completely. No diagnosis or repair can be made on a frozen system. Some companies will charge to thaw out your system but as mentioned earlier, simply running the heat will aid in the system thawing pretty quickly.

Rather it’s a quick fix or a lengthy repair, R. A. Styron will always do a thorough inspection letting you know exactly what is going on and the best plan of action. R. A. Styron’s knowledgeable technicians come with years of experience and the tools needed to get the job done correctly the first time. You can rely on an honest, cost effective, and efficient job no matter the repair required. If you live in the Hampton Roads area give R. A. Styron a call to schedule your repair today!



Leave a Comment