Why is My Air Conditioner Turning on and off?

Jack Russell dog sitting in front of a domestic electric fan because the air conditioner keeps turning on and off.

When an air conditioner (AC) turns on and off in rather quick successions, without running for longer periods, this is called short cycling. It’s fairly common, but when it happens it means there’s something wrong with the AC. Do not leave these occurrences alone. They will increase your energy costs, usually indicate a larger problem, and could lead to permanent damage of your unit, thus requiring a costly replacement. Short cycling also shortens your AC’s life span. Call a professional technician and have your unit inspected.

Any one of our experts at Chaves Heating & Air Conditioning can diagnose and repair this issue for you. Don’t delay. Call us at 877-7-CHAVES, so we can get your air conditioner back to its most efficient state for you.

While there are many possible reasons for short cycling, here are a few of the most common ones and what can be done to fix them.

Low Refrigerant

The coolant that flows through your system, helping to absorb heat and cool down the air inside your home, is called refrigerant. You may know it by its brand name of Freon®. When your refrigerant is low, the needed compressor-pressure levels are affected. This triggers your compressor’s low pressure control, shutting off your compressor. When the pressure rises and triggers your AC to restart, this causes the short cycling. If your refrigerant level is low, this indicates your have a leak, as refrigerant is cycled throughout the compressor, not burned off. Low refrigerant can also cause frozen coils. A professional technician can find your leak and prevent any further issues or damage.

Thermostat Location

Your thermostat acts as the sensor for your air conditioner, telling it when to cool your home. If its location is not optimal, such as near a window or too close to a vent, your thermostat will be sending misleading information to your AC. Suppose your thermostat is in the direct line of a vent’s airflow. This will cause the thermostat to think it’s cooler in your home than it really is, and your AC will shut off thinking it’s reached its desired temperature. Since the cool air is no longer flowing through the vent, the thermostat realizes your home is actually still too warm and triggers your AC to start up again. This is short cycling. Be sure your thermostat is located in a central location away from direct sunlight and vents.

Dirty Air Filter

Dirty air filters are one of the most common and easily remedied problems with ACs we see here in Hudson, MA. The dirty filters restrict airflow, which in turn causes so many problems, one of them being a frozen coil. This can cause your AC to malfunction and short cycle. Be sure to change your filters regularly to avoid any issues.

Oversized AC

An AC unit that’s too large for your home short cycles, because it cools your home too rapidly while it doesn’t dehumidify it properly. So it’ll shut down and start up frequently. You’ll more than likely also find that your home has hot and cold spots, and you’ll experience higher energy bills. If your AC is newly installed, talk to the technicians who installed it to see what they can do to help you.

Short cycling causes a whole host of problems with your AC, so if you notice your AC doing this, call one of our Chaves Heating & Air Conditioning technicians to assess the situation. You want your AC to cool efficiently and to last for years to come. Short cycling will short change you.

Need Air Conditioning Service?

Call us at 877-7-CHAVES or schedule your AC service online.


Chaves Heating & Air Conditioning provides heating, cooling, indoor air quality, commercial, and HVAC maintenance services to residents in Acton, Bolton, Clinton, Concord, Framingham, Lancaster, Leominster, Shrewsbury, Upton, Worcester, and other surrounding Massachusetts communities. Visit our service area page to learn more about how we can service you and to view the other communities in our core service area. Contact us today at 877-7-CHAVES or schedule service online.

Need HVAC Service?

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Call us at 978-562-5309!