Reasons Why Air Conditioners Freeze Solid

You turn on your air conditioner in the middle of a hot day, but notice that it isn’t cooling your home properly. Thermostat’s pointed to “cool” dial, the unit’s plugged in, but the air still isn’t getting any cooler. Chances are, the A/C’s own guts have frozen inside – but how does this happen?

One of the most common causes of a frozen A/C is a dirty air filter. Over time, dirt and grime accumulate on the filters and restrict airflow, thus keeping the cold air circulating inside. In turn, the unit’s guts freeze because the cold air can’t escape. Cleaning or replacing the filter can fix this.

Dirt and grime are not the only one that clog air filters. Improperly positioned furniture or any other items can block the A/C’s return air vent, or the opening where the air passes across the evaporator coil. Obstructive items can block overall air flow, so be sure to clear up the space near the air conditioner.

A malfunctioning thermostat is another culprit for internal freeze. If the thermostat dial isn’t working properly, the A/C will run continuously without turning off and on, even when the temperature’s set point is reached. This could definitely result in ice-covered coils.

Other reasons for the deep freeze may be an ailing evaporator fan or refrigerant leak. These fixes require a much more trained hand, so unless you’re trained to do air conditioning repairs, better call a service technician immediately.