A/C Failure: 3 Potential Causes Of Frozen Evaporator Coils

Has your central air conditioning become less efficient at cooling your home? There are a few potential causes, but one of the first things to check for are frozen evaporator coils.

Evaporator coils are in the air handler, which is the section of your central air system that's inside your home. Consult your manufacturer's guide for instructions in opening the handler to access the coils. Do the coils have standing frost? Then frozen coils are your problem since the frost keeps refrigerant moving through the system as quickly.

Here are a couple of potential fixes for frozen evaporator coils. Some are easy to perform yourself, while others you will want to leave to an air conditioning repair technician.

Air Filter Needs Changed

The air filter in your unit purifies the outside air so that pollen and debris don't end up inside your home. Filters need to be changed or cleaned periodically so that the outside debris doesn't buildup and block air from entering the system. Weakened air flow means less air is passing over the evaporator coils to help keep their temperature stabilized, which means that when the coils become cool they can start to frost.

Consult your owner's manual to see how often you are supposed to change your air conditioner filter. This is a job you can easily do yourself with the manual or by a few questions at the hardware store.

Refrigerant Leak

Your entire air conditioner system runs on refrigerant. The refrigerant begins in the outside condensing unit as a gas, turns into liquid in the condensing coils, passes inside to the air handler, and becomes gas again in the evaporator coils. It's that phase change in the evaporator coils that causes those coils to become cold. A fan then blows warm air across those cooled coils and back into your house.

An imbalance of refrigerant due to a leak can cause the evaporator coils to freeze up during that phase change. This is a major problem and should be handled by a professional technician. However, the repair might be so costly it's cheaper to simply buy a new unit. It's important to call a technician as soon as a refrigerant leak is suspected to maximize the chances of saving your unit.

Blower Motor

The air handler's blower motor and fan combination is important to both move warm air over the cold coils to cool your home, but also to keep those cold coils from becoming too cold. If the blower motor loses functionality, less warm air passes over the coils.

Unless you have electrician experience, leave the replacement of the blower motor to a professional company like Elite Heating, Cooling and Plumbing. It's a vital part in your air conditioner system and an incorrect installation could cause further problems.