Why Won’t My AC Fan Turn Off?

The most common reason that your Air Conditioner fan won’t turn off is because there is a stuck relay keeping the circuit closed. If it’s not the relay, your thermostat likely has failed, or has a shorted cable. While there are other reasons, these are the most common.

Before calling a service technician to start replacing components, check the thermostat settings first. Set the desired temperature above the current room temperature so the air conditioner unit turns off (set the thermostat below room temperature in the winter to check your furnace). Fan still blowing after a few minutes? Double-check the thermostat and make sure the fan is not set to ON, and that it still runs when switching it to AUTO or OFF (if your thermostat has an OFF setting).

After you’ve ensured that the settings are correct, contact your trusted HVAC technician to troubleshoot further and resolve the issue. Here’s what they may find:

Stuck Relay – Relays in your air conditioner unit help open and close electrical circuits to turn components, like a fan, on and off. Over time, relays can fail or stick together from electrical currents, causing a circuit to stay closed and constantly supply power.

Malfunctioning Thermostat – A faulty thermostat can cause your AC fan to run constantly by not knowing when the desired temperature has been reached. If the actual room temperature is below what your thermostat is set for, there’s a good chance you’re due for a repair or replacement.

NOTE: Sometimes entire air conditioner units (not just the fan) can run nonstop in an effort to reach the desired temperatures. Often, these inefficiencies are a result of clogged or restrictive air filters, dirty or frozen evaporator coils, dirty or blocked condensers, or low refrigerant. Schedule an annual air conditioner tune-up to keep your system operating at peak performance.

Although a constantly running air conditioner fan can help battle allergies by keeping the air filtered, it causes unnecessary wear on the motor and increased energy costs. Don’t worry, call Reddi and we’ll take care of your air conditioner, as well as check for any potential issues while we’re there.

Resources found on our website are provided as general guidelines and Reddi Industries does not assume any liability resulting from the provided information.