Tuckers Air Conditioning, Heating & Plumbing Blog

Why Is My AC Shutting Off Too Early?


Is this happening to you? You set your home thermostat for the usual daytime temperature when it’s hot outside. The AC turns on, you can hear the compressor running, cooled air starts to flow from the vents. Then the compressor shuts off, but the house hasn’t gotten cool enough. You fiddle with the thermostat, and maybe the AC starts to cool again, but then shuts off early, and so on… 

This is a problem since you’ll have to go through hassles and raise your electric bills to try to stay cool. Why is this happening, and what can you do about it? We’ll look into that below.

The thermostat is faulty

One of the first problems to investigate is whether the thermostat is the source of the problem. If the thermostat is miscalibrated and reading incorrect temperatures in the house, it may sense that the AC has sufficiently cooled the house before it actually has. 

For example, a thermostat that’s reading the house as 3° cooler won’t keep the AC running to reach a setting of 78°F; instead, it will shut it off when the house is still 81°F. Playing around with the thermostat to overcome this problem isn’t a good idea, because it wastes power and puts strain on the AC that can lead to repairs or even the system overheating. It takes professionals to repair the thermostat through recalibration.

The air filter is clogged

Did you forget to put in a new filter in the HVAC system before you started using the AC for the season? If so, then the current filter may be clogged, and this can force the air conditioner to shut down early. Put in a new filter to see if this fixes the problem.

The air conditioning system is too old

If you’ve had this AC for more than 10 years, this failure to keep the compressor running until it reaches the home’s cooling needs may be a warning that the whole air conditioner is declining and heading toward failure. You can ask our technicians about a new AC installation in Frederick, MD: we’ll give you an honest assessment of the problem and go over the long-term costs of continuing to repair the AC versus getting a new one. 

The AC is short-cycling

Short-cycling is a general problem for an AC where it gets caught in its start-up cycle. Instead of completing a full cooling cycle (which takes at least 15 minutes), the system shuts off early and then turns back on again a short time later. This repeats over and over. Not only does this make it hard for the air conditioner to fully cool the house, but it also puts heavy wear on its components and drains immense amounts of power—the AC uses the most electricity when it starts the compressor. 

There are many different causes of short-cycling, from an oversized air conditioner to refrigerant leaks and bad ductwork. You’ll need to have professionals check out the system to discover why short-cycling is occurring and then have it corrected. 

Look to Tuckers Air Conditioning, Heating & Plumbing to solve any home cooling problem you may experience. We pledge to exceed expectations at every turn.