Manassass, VA

PO Box 10258, Manassas, VA 20108

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Why is my AC Freezing Up?

If your air conditioning hasn’t been working the last thing you would expect to see are your air conditioner’s coil or refrigerant lines encased in ice, especially on a hot summer day. However, your AC freezing up is a more common problem than you might think.

The first thing you need to do is turn your AC system off. If your unit is still working to cool the air, then it will also continue to frost. In some severe cases, it may even be beneficial to turn on your heat to help the frost melt away. While your system is thawing it is important to take into account the water levels of the unit. If the drain pan inside of the machine’s evaporator coil overflows you may experience serious water damage throughout your AC unit.

Let’s take a few steps back though to discuss the why. The first and most important question to ask and answer is, “WHY, is my AC freezing up?” Once you are able to determine the why it is much easier to determine HOW to fix your unit.

Reason's Why Your AC Is Freezing Up?

1. Poor Airflow

If your unit is unable to get enough air, then there won’t be enough heat to aid in preventing the condensation located on the coil from turning into ice. Make sure to check and replace your air filters before doing anything else. It is important to know that clean filters can still cause poor airflow! Make sure to take the time to inspect all of the air vents in your home. You can do this by holding your hand in front of the vents to feel if the air is coming through. If there are no blocked ducts, closed or blocked grates, and all dampers are open, then poor airflow is most likely not the cause behind your AC freezing up.

AC freezing up

2. A Damaged Blower Fan

The blower fan on your air conditioning unit helps get cold air where it needs to go while pushing warm air outside. When the air inside of your unit cools it becomes denser and doesn’t travel as well as warmer air does. The blower fan helps move the cold air where it needs to go by essentially sucking out the hot air from your home, and moving the cooler air in to replace it. The effectiveness of your air conditioning unit relies 100% on your system having the correct balance of airflow and air pressure.

If your blower fan is broken, it will significantly change the airflow happening inside of your system. An abundance of condensation will build upon the coils, and the water droplets will not drain properly. Without hot air being pushed over the proper areas, a broken blower fan may be the culprit behind your AC freezing up.

3. Low Refrigerant

Another reason behind your air conditioner freezing up could revolve around your system’s refrigerant chlorodifluoromethane (which is also known as r22). This refrigerant has different physical properties at different levels of pressure and certain pressure changes can cause the r22 to act differently.

If moist warm air from your house moves over the evaporator, that moisture will then condense and freeze on the coils causing ice. If it is just minor frost you may not even notice but too much ice will begin to affect the flow of air. If left to build up, this ice will then begin to act as an insulator, preventing your air conditioner from working properly.

4. Dirty Coils

One of the most common causes of your AC freezing up is a dirty AC coil. The presence of ice in your system obstructs proper airflow, so what was once just a little bit of frost can become a giant block of ice quickly. Your evaporator coils have the potential to freeze because air conditioners work to dehumidify as they cool. The system will pull water from the air, which produces condensation that can build up on the coils. While this isn’t usually an issue, if your drip pan where the condensation produce falls into is overflowing, the coils can quickly become waterlogged and will eventually freeze.

Dirty coils may be the menace behind why your AC is freezing up because the layer of dirt on top of the coils can prevent the coils from absorbing water fast enough.

How to Keep your AC From Freezing Up Again

When it comes to making sure your AC will not freeze up, there are a few things that you can do. These preventative measures will help you combat freezing before it even has the chance to begin.

Pay Attention to your Vents

Checking to make sure that your supply and return vents are open and not blocked is extremely vital for proper airflow. If you have furniture sitting in front of or on top of vents make sure to move it so that air can easily pass through. Another important thing to do is to make sure to not close more than two to three supply vents at one time. While theoretically, you may think this is saving you money, you may be restricting your air flow too much and may cause your air conditioning unit to freeze up.

AC freezing up

Change and Check your Air Filters

We mentioned before that a clogged or dirty air filter may be impacting the airflow in your home. Making sure to change your air filters regularly will help to prevent your AC from freezing up as well as help to ensure better indoor air quality.

Check your Condensate Drain Line

If any part of your condensate drain system becomes clogged the water in the drip pan can become backed up and can even overflow over time. This excess moisture leaves your evaporator coil vulnerable to freezing.

Make Sure your Blower Fan is Working Correctly

A faulty blower fan can make life difficult for you and your air conditioner. This component of your air conditioner is responsible for generating airflow, so if there isn’t enough airflow the coil will freeze, or sometimes the system just won’t work at all. If your blower motor isn’t working and the cause of your AC freezing up it may be best to let the professionals step in.

Have our Trained Technicians Help with Regular Maintenace

The best way to prevent your AC from freezing up is with regular air conditioning maintenance. This maintenance will help to fix small problems before they become much larger ones. Our team at Express Tech Air is here to help you with all of your air conditioning needs. Whether your system is freezing up or just not working at all, we are here 24 hours a day, 365 days a year to help! Contact us today for more information about our residential air conditioning services.