Once the summer heat rolls around, many homeowners crank up their air conditioners to try and stay cool. If you overwork your air conditioner, you may be surprised to find frost on the outside of the unit. Frost on your air conditioner may seem out of place in such hot weather. However, there are a few possible explanations for the ice.

The following are some possible reasons that your air conditioner might have frozen over.

1. Limited Air Flow

One of the most common reasons for an air conditioner to freeze is blocked or limited airflow. Often, an air conditioner can’t run efficiently if dirt is clogging the air filter. If your air conditioner has limited airflow, turn the system off to start the defrosting process. Once the system has defrosted, try replacing the air filters.

You can prevent your air conditioner from freezing in the future by regularly replacing air filters. Use high-quality filters and replace them every two to three months. Damaged ductwork may also be limiting airflow to your air conditioning system.

If you can, inspect your ductwork for leaks, disconnected portions, or bends that could obstruct airflow. You may need to hire an HVAC technician to inspect any ductwork in hard-to-reach areas, like the attic. You should also hire a professional HVAC technician to conduct annual tune-ups on your air conditioner to keep your system clean and running efficiently.

2. Leaking Refrigerant

Another common cause for a frozen air conditioner is leaking refrigerant. You can identify if your refrigerant is leaking if you can see stains or dirt on the unit. Most dirt or stain marks are present under the A/C cover.

If you suspect leaking refrigerant, call an HVAC technician to locate and seal the hole. He or she will also be able to refill your air conditioner with refrigerant. If you try to add more refrigerant before sealing the hole, you won’t resolve the issue.

Even if you can get a professional HVAC technician to refill your coolant and make your A/C run again, it will only temporarily solve the problem. The only way to resolve leaking refrigerant is to seal the hole or buy a new system. If you have an older system that requires expensive repairs, consider investing in a new air conditioner.

3. Exceeded Temperature Range

Each air conditioner has a limited temperature range. Don’t try to use the air conditioner when outdoor temperatures are under 62 degrees, or your air conditioner may freeze. You may need to buy an air conditioner that can operate in cooler temperatures if you want to reduce your home’s temperature during cooler weather.

4. Dirty Evaporator Coil

Dirty evaporator coils can also cause ice to form on your air conditioner. You can check the coil for dirt by looking around the outside condenser or on top of the unit for debris. Sometimes, the coil appears clean from the outside but isn’t clean on the inside. If you notice pressure readings that are higher than normal on your unit, you may have a dirty coil.

Call an HVAC technician to replace or clean the evaporator coil if you need help locating dirt or cleaning the unit.

Never operate your air conditioner if the evaporator coil is broken. Operating an air conditioner with a broken evaporator coil can cause damage other parts of your air conditioner. In cases of severe damage, you may need to replace your entire air conditioning system.

If ice is forming on your home’s air conditioner, call an HVAC service immediately. An expert technician can help you pinpoint and repair any damages to your unit to prevent any problems in the future.