6 Common Reasons Why AC Turning On and Off frequently (Short Cycling)

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If your air conditioning turns on and off frequently, you may be experiencing short cycling. Short cycling is when an Ac turns off after every 15 minutes or even after a short time immediately turning it on.

The following are disadvantages of short cycling:

  1. A lot of energy is wasted. This hikes up bills unnecessarily.
  2. The achieved temperatures are not comfortable or desirable.
  3. Short cycling simply means there is a fault in the systems which should be corrected.

One can simply correct and rectify short cycling alone without intensive prior training. Some fixes are easy, but some are complex which might require a trained technician.

Here are the 6 most common reasons your air conditioner may short cycle.

1.  A faulty thermostat

The thermostat is the brain of the air conditioner. The thermostat’s function is to send signals to the air conditioner system, turning it on or off respectively.

Like any other electrical equipment, a thermostat can malfunction.

The thermostat could be faulty or its wiring. If the thermostat is faulty, it should be replaced. If the wiring is wrong, it can be corrected, and the system will continue working. A qualified technician should check this.

2. Clogged Condensate Ducts

The air conditioner absorbs the moisture from your home’s warm air.

The condensation (moisture) is drained via a pipe, preventing it from leaking into your house.

A clog can also be created by debris and dirt in the condensate pipes. The condensation, instead of draining outside your home, backs up into the drain pan.

The water levels may rise up and, at a certain point, trigger a switch that responds by turning the air conditioner off.

You can quickly clear the line by locating the condensate line in the air handler (indoor unit). Pour distilled vinegar into the line after removing the cap and wait for 30 minutes before flushing the line with water.

One should seek help from a professional AC technician if the clog persists or the air conditioner keeps shutting off unnecessarily.

3. Lack of sufficient airflow into the AC

The Ac should properly suck in warm air in your home to effectively release cool air and cool your home. Lack of enough air flowing in the AC causes components such as the blower to overwork to produce the same results. As a result, the components overheat, and the AC shuts down.

A dirty air filter is the most common restriction of air flowing into the AC.

Once the filter gets clogged with dirt, air cant flow through to the AC. Air filters should be checked regularly and subsequently cleaned to remove dirt. If need be, the air filter should be replaced with a new one.

Causes of low airflow include:

  • Fan Problems:-A malfunctioning fan motor gives the air conditioner a hard time sucking enough air. A trained technician will have to inspect the fan and even replace it if faulty.
  • Blocked Vents:-All vents should always be open and unobstructed. This ensures air easily enters and exits the vents, respectively.
  • Leaking ducts:- A trained technician can help you look for disconnected ducts or leaks and repair or replace them effectively.

4. An oversized AC

If the air conditioner is oversized, it will end up cooling your home at a very fast rate and then shut itself off. Always consult an expert when sizing the right air conditioner for your home. This will save you a lot of downtimes and save you from unnecessary discomfort.

5. Wrong thermostat installation

If the thermostat is placed at the wrong location, it will cause short cycling. A trained technician can easily rectify this.

Such locations include direct sunlight reaching the thermostat(near windows) or under an AC vent. It becomes very difficult for the thermostat to detect the house’s real temperature in such positions correctly.

6. Low Refrigerant Levels.

The cooling substance in the air conditioner that helps in cooling your home is known as a refrigerant. A leak in the system causes a low level of refrigerant in the air conditioner.

This causes changes in pressure, and hence a switch is triggered to shut down the compressor, which is an essential electrical appliance in the air conditioner system.

The air conditioner stops cooling air once the compressor shuts down. Once the pressure levels return to normal, the compressor will automatically switch on.

A trained technician should regularly inspect for leaks and low refrigerant levels to prevent the system from consistently shutting itself off.

Signs of A Refrigerant Leak

  • Hissing sounds from the air conditioner.
  • Pooled water at the frozen evaporator coil(indoor unit)
  • Loss of cooling power.
  • It spiked energy bills.


We know that short cycling can be frustrating, and it’s not something you want to deal with. Fortunately, we have the knowledge and expertise needed to get your air conditioner back on track so you can enjoy a cold environment without interruption. If you need help or more information about our services, feel free to contact us today!

Related read: 9 Most Popular Air Conditioner Problems & How To Deal With Them

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