Help! My air conditioning unit is frozen up!

If you are noticing that a hot day is getting hotter as you step in your house, you may have a frozen air conditioning system! Your central air conditioner may freeze up for a few different reasons. Insufficient airflow across your air conditioning unit’s evaporator coil, low levels of refrigerant, incorrect operating temperatures or even mechanical failure can all cause your system to freeze up.

Never fear though, your friends at UGI Heating, Cooling & Plumbing have a few simple tips that you can use to help determine the cause of the issue.

Check the air conditioning filter, if it is dark and filled with dirt, it needs to be replaced. The dirty filter may be restricting air flow causing decreased efficiency of the entire system and may lead to a freeze up. In many cases frozen coils can damage the fan or compressor by overheating them.

Restriction in airflow from your ductwork or extremely dirty ductwork. Your A/C system is designed to push and pull air through a precisely measured network of ducts. These ducts allow for optimal airflow which minimizes the stress and load on the system. When dirt builds up in your ducts, it changes the amount of air that can freely flow through the system. When this happens, your system runs inefficiently which could eventually lead to issues down the road. It is advised that you have your unit cleaned each year. Give your friends at UGI Heating, Cooling & Plumbing a call to schedule an annual cleaning and tune-up at which time our technician can advise you on ductwork cleaning.

You may have a water leak from the indoor unit. During the cooling season, the condenser in your A/C unit produces a lot of condensation which is supposed to run down the coils. This condensation on the coils may freeze. When the coils start to defrost, that excess water may overflow your collection pan and leak through the equipment and onto the floor.

A system undercharge with refrigerant could also cause a freeze up. If your system is low on refrigerant your evaporator coil’s temperature drops to below 32 degrees, causing moisture will freeze on the evaporator. This restricts the airflow, which amplifies the problem. On systems that are severely undercharged you may find ice outside on the outdoor unit’s compressor.

If the issue is just that your filter needs to be changed, you may be able to resolve the issue yourself. Be sure to turn the AC unit off while leaving the fan on (switch system settings to Fan Only) to allow the unit to thaw. Then change your filter and power the system back up to see if you are back in business.

If you need to have a professional come look at your system, make sure that you have defrosted the system completely and leave it turned off for when the technician arrives. Your technician will not be able to properly check the system mechanics and refrigerant levels while the system is frozen.

Yearly maintenance is recommended to check for possible mechanical failures before they occur and to keep your system operating at peak efficiency. Call your certified UGI Heating, Cooling & Plumbing technician to schedule an appointment to have your system evaluated and repaired. We service homes throughout Eastern and South Central Pennsylvania, the Lehigh Valley and more. We proudly live in, and serve, the following areas:

Eastern Pennsylvania

South Central Pennsylvania