Why is There Ice on my Air Conditioner?

It’s the middle of summer and you turn on your AC to cool down, but you get a blast of cold air instead. You go to the thermostat to adjust the temperature and see that it is set at 72 degrees, so why is your room still freezing? The answer could be that there is ice on your AC unit!

Technically, your AC system doesn’t use ice to cool down your home. However, the unit’s coils can freeze if the system isn’t working correctly. So, if you see ice on your AC unit, it’s a sign that something is wrong.

There are several reasons why your AC system’s coils might freeze. Here are a few of the most common:

Problem With The Refrigerant

Your AC uses a refrigerant to cool your home. This substance flows through your AC unit, and as it does, it absorbs heat from indoors. The refrigerant then carries this heat outdoors, releasing it into the air. If there is an issue with your AC’s refrigerant, it can cause ice to build up on the evaporator coils. This ice can eventually lead to a complete breakdown of your AC unit.

Dirty coils

Dirty coils can undoubtedly lead to ice build-up in your AC unit. The coils are responsible for transferring heat, so when they are covered in dirt and debris, they cannot work as efficiently. As a result, your unit puts in extra work to cool the air, causing ice to build up on the coils. In addition, when the coils are dirty, they cannot absorb heat as effectively, leading to ice build-up.

Dirty Air Filters

One integral component of your AC unit is the air filter. The air filter’s purpose is to trap airborne particles such as dust, pollen, and pet dander, which can help improve indoor air quality.
However, if the filter becomes clogged, it can restrict airflow and lead to several problems. One such problem is ice build-up on the evaporator coils. When the evaporator coils are cold but cannot circulate enough, moisture in the air can condense on them and freeze. This can cause your AC unit to malfunction and may even lead to a complete system failure.

So, how can you prevent ice build-up on your AC unit?

The best way to prevent this problem is to have your AC unit serviced by a professional at least once a year. A professional can clean the coils and air filter, and they can also check for any issues with the refrigerant. In addition, you should make sure to change your home’s air filter regularly. Doing so will help improve airflow and prevent dirt and debris from clogging the filter.


While it may seem strange, ice on your AC unit signifies something wrong. There are several reasons why this may happen, but the most common are dirty coils and filters or an issue with the refrigerant. As explained, dealing with this problem as soon as possible is essential to avoid further damage to your AC unit. If you detect ice building up on your AC unit, turn off the unit immediately and call a professional for help. Continuing to use the unit could damage it beyond repair. Ice build-up is a serious issue that should be addressed as soon as possible to avoid costly repairs or replacements.