An air conditioning unit freezing up is a common problem among homeowners and determining the primary cause can be challenging. Whether you have a window unit or a central air conditioning system, several reasons can cause your unit to freeze up. A frozen AC system will not be able to cool properly and may even completely ruin the unit’s internal parts. Here are the main culprits of a freezing air conditioning unit.

1. Restricted Airflow

If there is insufficient air flowing through the AC unit, your evaporator coils can freeze and even cause your entire system to freeze and stop functioning. The most common cause of limited airflow is clogged or dirty filters. Dirt and dust can accumulate on the evaporator coils, clogging them in the long run. Airflow issues can also be caused by a malfunctioning fan or blocked vents and ducts.

Depending on the cause of the insufficient airflow, you might need to repair your ducts, clean your ductwork, or change your filters. To prevent this problem from recurring, consider having the ductwork sealed and regularly change the filters.

2. Stuck Contactor

A contactor refers to a small part found on the outside part of an air conditioner. If the contactor gets stuck, it can prevent the AC from entering the cooling mode or even cause the outside system to run when it’s not supposed to. You can notice this problem when you turn off your AC unit at the thermostat. If the outdoor part of the air conditioner continues to run after switching off the thermostat, you might be dealing with a suck contractor.

The only solution to this problem is to switch off the unit at your circuit breaker and have your HVAC contractor inspect the system and fix the issue.

3. Low Outdoor Temperatures

The temperatures outside must be within a specific range for your air conditioning unit to run effectively. If the outdoor temperatures are below 60 degrees Fahrenheit, even an AC unit in good working condition cannot function properly. If you run your air conditioner when the outside temperatures are extremely low, the pressure within the unit may drop, causing it to freeze up.

To solve this problem, turn off your AC system and allow it to thaw. Turning off your AC at night when temperatures are extremely low can prevent your unit from freezing up. You can also run your AC in fan mode or open doors and windows to ventilate your rooms.

4. Low Refrigerant Levels

If you regularly find yourself adding refrigerant to your AC system, you might be dealing with a leak inside the unit. Leaks may develop as the unit’s parts rub together or vibrate with time. They can also occur when fittings or joints become loose. Leaks can cause pressure in the evaporator coils to drop. As a result, moisture collects and later freezes on the coils. With time, the ice can build from inside the unit to the outside parts until the system stops working. Have your HVAC expert locate and repair all the leaks and refill the refrigerant.

5. Mechanical Components Failure

Your air conditioning unit can freeze up if there are some mechanical failures within the system. For example, broken valves, kinked refrigerant lines, a faulty blower fan, or a damaged fan motor can cause your AC unit to freeze up. Have a licensed AC expert examine and make the necessary repairs and replacements. Regular inspections and maintenance of your cooling and heating systems can also help ensure that all components function properly.

6. Dirty Evaporator Coils

A dirty evaporator coil restricts airflow through your AC, causing ice to form on the unit. In addition, as dirt continues to build up, your system will produce less cool air, causing it to freeze up. A dirty evaporator will also make your unit less efficient and might damage the system’s compressor in the long run.

To prevent your AC from breaking down, turn off the system until the coils get replaced or cleaned by an HVAC professional. Also, cleaning the evaporator coils regularly during routine checks can prevent this problem in the future.

Final Words

As you can see, your air conditioning unit can freeze up due to various reasons. However, you can avoid most of these causes with regular tune-ups and basic maintenance. If your system keeps freezing up, turn it off immediately and contact an HVAC professional from Medcalf Mechanical. We will inspect your AC system and solve the issue to restore your comfort and peace of mind.

Our company also offers a wide range of heating, cooling, refrigeration, and air duct services to the residents of Terre Haute, IN. Contact us now for any AC-related services, and our technicians will be glad to help.