Why Your Air Conditioner Is Not Cooling and Simple DIY Checks

The reasons an AC stops cooling are often multiple: a dirty air filter, blocked airflow around the indoor unit or condenser, incorrect thermostat mode or a set temperature that is too high. In some cases the refrigerant level is low or the compressor is malfunctioning, and those issues require a qualified technician.

Safe things you can try first include making sure the remote is set to “Cool” and the temperature is lower than the room, turning off the unit and waiting a few minutes before removing and cleaning or replacing the air filter if it’s dirty. Wash the filter with clean water, let it dry, and check that both indoor and outdoor units are free of leaves, dust, or other obstructions that could hinder the condenser’s heat release.

Stop and call a professional if after cleaning the filter the AC is still warm, you hear unusual noises, see ice on the coils, notice water leaking from the indoor unit, or suspect a refrigerant leak or electrical problem. Turn off the unit and let a licensed AC technician handle refrigerant work and any electrical repairs to keep you safe.