Air Conditioner Won't Shut Off | AC Keeps Running

My Air Conditioner Keeps Running

When Turned Off

If your AC keeps running and you’re noticing one of the issues above, you’re in luck! Below, we’ll explain the steps to solve each of these common AC problems:

Fan is set to ON

If your thermostat setting is in the ON position instead of AUTO, this is a very simple problem to fix.

An AC fan typically runs separately from your air conditioning system. These two pieces of equipment work together to bring cool, comfortable air to your home. However, they don’t always work in synchronization. For example, the fan may shut off while the AC keeps running.

If you notice that the fan setting on the thermostat is set to AUTO, this means the fan will only run when your air conditioner is powered on and pumping cool air. However, if it’s set to the ON position, the fan will continuously run, even if the AC system is completely off.

Not sure if this is the problem?

To diagnose the issue yourself, head over to your thermostat and look at the fan setting. If it’s in the AUTO position, there could be another issue causing the trouble.

Faulty Thermostat

If your air conditioner won’t shut off, you could also have a broken thermostat. One way to tell is if you notice the indoor temp is lower than the thermostat setting you chose. If a thermostat is malfunctioning, it may have trouble understanding the temperature of the room. This can cause your AC system to run continuously or power on when it shouldn’t. 

Unfortunately, this issue usually means you need a new thermostat. Be sure to call an HVAC technician and ask them what to do next.

Short circuit

Another common culprit is when your AC unit short circuits. When this happens, whatever you enter on the thermostat probably isn’t recognized. That said, your AC system doesn’t know how to adjust. If you set your thermostat to OFF, the command isn’t getting to your AC unit. If your air conditioner keeps running when turned off, a short circuit could very well be the problem.

This air conditioning issue requires skilled HVAC expertise, so call a professional provider for assistance.

Hot outdoor temps

Are you dealing with this AC problem in the middle of July? If so, it may be due to the scorching outdoor temps. This issue is especially common in Arizona, Texas, Florida, and other locations with soaring summertime weather.

If the temperature is too warm, your AC unit may have trouble keeping up. To determine if this is the problem, crank up your thermostat 5-10 degrees and check to see if your unit powers down. If it does, this probably means your AC system is too small for your home. If an AC unit isn’t big enough for a space, it will have a hard time keeping up with the demand. This is a leading cause for why an air conditioner keeps running when turned off.

Sadly, the only way to fix this issue is to buy a new unit. If you call a professional, they can recommend a system that’s perfectly sized for your home.

Malfunctioning relay switch

Relays work by opening and closing electrical circuits that run throughout your air conditioner, including the fan. Over time, these relay switches can get stuck or damaged, resulting in poor communication between the thermostat and fan. While you can try to turn the AC system off, the fan may continue to work.

Unfortunately, this is a problem you shouldn't handle on your own. As this could be an electrical issue, it’s best to call a trusted professional.

If your air conditioner keeps running when turned off, be sure to read this blog to make an educated decision on what to do next.