If your air conditioner keeps running when turned off, you're right to be questioning a number of things. Not only can it be annoying, but it’s also a drain on your energy bill and can indicate that you have a serious problem with your AC unit. If you’ve noticed that your air conditioner won't shut off or the AC is off but the fan keeps running, there are a few things that could be wrong with it.
Why Does the Fan Keep Running On My Air Conditioner?
1. The Unit Size Could be Wrong
When you notice that your AC is off but the fan keeps running, stop and think how long this has been happening. If it’s been a constant issue, then it’s very possible that your AC unit is the wrong size for your home. A properly sized air conditioning system will be energy-efficient and run somewhat continuously to maintain air temperature, but it shouldn’t run constantly.
If the unit is too small, it will need to work harder than normal to cool your home. If it’s too large, it won’t be able to remove moisture from the home properly. This usually results in a clammy feeling to the air that the air conditioner will work constantly to remove, without success, giving you an air conditioner that won't shut off. If this is the case, you may need to get your HVAC system replaced.
2. The Air Filter May be Dirty
While a constantly running air conditioner could indicate a huge problem, it could also be a simple fix. Clogged air filters prevent the AC unit from processing air properly. The dirt and debris collected in the air filter block airflow and make it so the AC unit needs to work a lot harder to sustain the desired temperature. Replacing your air filter every 30 to 90 days can resolve and prevent this issue.
3. Your Thermostat Could be Broken
If your air conditioner keeps running when turned off, it could have more to do with your thermostat than the AC unit itself. If your AC is off but the fan keeps running, you could have a thermostat glitch.
Your thermostat could be registering the wrong conditions in your home, causing your AC unit to run continually because it’s being told the home still needs to be cooled.
To test your thermostat, make sure that it’s in the correct “Heat” or “Cool” setting, and check to see if it’s set on an automatic mode or if the fans are in an always-running mode. You can also test your thermostat by changing the temperature higher or lower a few degrees and testing to see if your AC unit turns on or off.
If your air conditioner won't shut off or respond to temperature change, it’s likely an issue with your thermostat. If none of these tests work, consult an HVAC technician to diagnose the issue and get it resolved.
4. Excessive Heat or Humidity
Your AC unit is designed to keep your home cool and comfortable, removing unwanted moisture and heat from the air. In times of extremely hot or humid weather, your air conditioner will need to run much harder and more regularly to keep your home temperature as desired. You can offset this by installing ceiling fans, using box fans, or even talking with your HVAC technician about getting a whole-home humidification system for your home to take some of the workload off your AC unit.
5. Your Air Conditioner Needs Maintenance
Sometimes when a machine isn’t working properly, it simply needs an inspection, a good cleaning, and maybe a few tune ups. Your AC unit is no exception. Regular air conditioner maintenance can keep your equipment running smoothly just like any other appliance. Make sure to get your HVAC unit checked at least once per year, though ideally twice: once in the spring before the hot weather of summer comes, and once in the fall before the harsh cold of winter.
These checkups will better ensure that your HVAC unit is ready for the weather change. An HVAC technician should clean your unit and inspect it for potential problems, helping your system run as efficiently as possible.
Schedule Your AC Inspection Early
It’s always better to correct an issue with your air conditioner before it becomes a serious problem. If your air conditioner won't shut off, or you're noticing any other peculiarities with your unit, contact the experts at John C. Flood to get your unit inspected and the problem resolved as quickly as possible so you can go back to whole-home comfort.