Why Is My AC Cycling On And Off?

8 November 2014
 Categories: , Blog


If your air conditioner keeps turning on and off, it probably is not generating enough cool air to condition your home to the right temperature. Turning on and off is technically referred to as short cycling. The problem will shorten the life of your AC unit and will also increase your energy costs. Unfortunately, there is more than one possible cause of your AC cycling on and off.

The AC is Too Big

Your AC unit might be too big for your home. An AC unit that is sized correctly will be cooling the air about as quickly as the heat is entering. If the unit is too small, it'll run constantly and will never fully cool your home. However, if the AC cools the space very quickly, it will then cycle off. While it may keep your home adequately cool, cycling on and off uses a lot of energy. Also, the unit might not remove enough humidity from the air.

There are Electrical Problems

The AC may turn on and off because it has an electrical problem. To function properly, an AC unit needs a steady supply of electricity and must not have any damage to the wires or connections. If so, the unit might keep cycling on and off. The AC may also regularly blow fuses and trip the circuit breaker.

The Thermostat is Malfunctioning

The thermostat is the device that determines how hard your AC works. If there is a problem with the thermostat, it may signal that the AC cycle off earlier than necessary. Luckily, thermostats are usually not expensive to replace.

The Compressors are Getting Older

AC compressors that wear out can start to cycle on and off. This will often happen as your AC gets older. However, the compressor can wear out sooner if you have a blown fuse or burnt wiring. Motors also have overload protectors that sometimes break and this can cause damage to the compressor.

There Isn't Enough Refrigerant

The AC unit needs a consistent amount of refrigerant to work properly. If you do not maintain the correct level of refrigerant, the AC will have poor cooling performance and the unit might cycle on and off repeatedly. Low refrigerant usually results from a refrigerant leak or from an incorrect refrigerant charge. If there is a leak, adding more refrigerant is only a temporary solution and you will need to eventually have the leak located and repaired.

The Coils are Frozen

When the coils freeze, the air filters might be dirty. By cleaning the filters and shutting the AC off to allow the coils to thaw, the AC unit will not cycle on and off. Otherwise, the unit will continue to malfunction.

If you are concerned with your AC unit cycling on and off, contact a professional such as those at Atlantic Heating and Cooling or others to help keep you cool.