Why Does My Central AC Shut Off Every Few Minutes? A Tampa Tech Answers

July 12, 2018

If your air conditioner keeps turning off and on by itself, your AC likely has a problem called short cycling.

Short cycling is bad news for your wallet and your AC system for 2 reasons:

  • Short cycling raises your energy bills

  • Short cycling causes additional wear and tear on your AC, which shortens the lifespan of your system

Since short cycling causes expensive damage, you’ll want to fix whatever is causing the issue ASAP.

In this article, we’ll look at 4 common causes of short cycling, and what you (or a professional) can do to fix each of them:

  1. Thermostat is in a bad location

  2. Dirty air filter

  3. Refrigerant leak

  4. Oversized air conditioner


Want a pro to stop your AC from short cycling?

Or visit our AC repair page for more information about our services.


Cause #1: Thermostat is in a bad location

If your thermostat is in a bad location—meaning it’s in a spot that’s usually a different temperature from the rest of your home—the thermostat can be “tricked” into thinking your home is hotter or colder than it actually is, which can cause your AC to turn on and off repeatedly.

Bad locations for a thermostat include:

  • Under a supply vent

  • Near a window

  • Next to a door that leads outside

Solution:

Have a professional reinstall your thermostat in a better location.

Cause #2: Dirty air filter

A dirty air filter could be what’s causing your AC to short cycle.

Here’s why: When an air filter gets too dirty, it restricts airflow into your air conditioner. Without enough warm air being pulled into your system, your evaporator coils can freeze over, which would cause your AC to short cycle.

Solution:

Check your air filter. If it looks like the one on the right in the image below, it’s dirty and you should replace it.

Dirty Vs Clean Fiberglass Air Filter1

If you change your filter and your AC keeps freezing over (you’ll know because you see pools of water around your indoor unit), contact a professional for help.

Cause #3: Refrigerant leak

Refrigerant is the liquid/gas that removes heat from your home’s air. If you have a refrigerant leak, it lowers the pressure in your system, which could trigger the low pressure switch at the compressor.

Once this switch is activated, your compressor will shut off. Then, pressure will rise and tell it to turn on again, and the fast on/off cycle will repeat.

Solution:

Contact an AC tech to verify if you have a refrigerant leak. If you do, you’ll need them to fix it. Refrigerant is a harmful irritant to humans, so make sure only certified professionals handle it.

Related reading:

Cause #4: Oversized air conditioner

If your AC is too big for your home, then it will cool your home really fast and then shut off.

While that may not sound like a negative, it is. You see, if your AC cools your home too fast, you’ll run into issues like:

  • High energy bills

  • Increased humidity

  • More hot and cold spots in your home

Solution:

Contact an HVAC expert to perform a cooling load calculation. This calculation takes into account many factors that will tell you exactly what size you need for your home.

Related reading: What Size Air Conditioner Do I Need For My Florida Home?

Need a professional to fix your short cycling problem?

We’ll send over one of our trusted professionals to help fix whatever is causing your air conditioner to shut off every few minutes.

For more information about what to expect when you hire us, visit our AC repair service page.


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