Why Does My Air Conditioner Keep Running When Turned Off?

If your air conditioner keeps running when it’s turned off this could be a sign of shorted thermostat wiring. A continuously running air conditioner could also be triggered based on the settings selected for the unit. Although an easy solution might be available by just changing the settings of the thermostat, it’s more likely you’ll need to bring in a professional to assess and fix the problem.

Common Reasons Why Your AC Won’t Stop Running

There are a few common reasons why your AC is continuously running. Depending on the cause, you may need to contact an HVAC professional for repair. Let’s break down the most common causes of a continuously running AC unit.

Thermostat

If your thermostat becomes damaged or completely stops working, your AC unit could get stuck in a continuously running state. This usually isn’t an expensive fix but it’s best to get it sorted out quickly before more serious damage develops.

Limit Control Switch

If your thermostat is in working order, it may simply have gotten flipped to a manual setting. You’ll want you limit control switch to be set to auto in order to follow any other settings indicated on the thermostat.

This is a fix you can easily DIY. We cover the details in ‘Try These DIY Fixes’.

Outside Heat

Outside heat can play in your AC’s misbehavior. If you’ve set your thermostat to a specific temperature, your system will run until it reaches that temperature. Then it will flip back on each time the temperature of your home goes about what was designated.

This could become a problem if you keep your blinds open during the day, especially mid-day. The sun will beat into your home and cause the temperature of the house to rise, thus kicking the AC unit into action to cool it.

Wiring

This plays back into problems with your thermostat. Your thermostat may appear to be on. However, the wiring may still be causing problems in your AC unit. You’ll need to contact a professional for any problems with your wiring as this can be difficult, and potentially dangerous, for homeowners to DIY.

Is It Normal For My AC To Run All Day?

It is concerning when your AC won’t stop running even when turned off and it could be an indicator that something is wrong within your system. An AC unit that is too old or too small for your home may run all day which can only be fixed with a complete replacement of your AC unit.

Try These DIY Fixes

While you’re waiting on your HVAC technician to arrive, check out these spots around your unit. More likely than not, this will only put a bandaid on a larger issue. But it will help get your unit under control until a professional is able to make an assessment.

Check Your Thermostat’s Settings

Even before you call an HVAC professional, checking your thermostat settings should be the first step you take. This can lead to a simple, free solution to your problems. If your thermostat was accidentally reset it could cause the AC to begin running continuously.

To check the thermostat, bump the thermostat to about the room’s current temperature. Theoretically, the AC will be notified of this setting change and shut off the airflow.

If this doesn’t stop within a few minutes, you’re likely dealing with an issue unrelated to the thermostat. At that point, it’s time to call in an experienced HVAC professional who can quickly and easily identify the problem.