Why does the air conditioner switch itself off?

What to do if the air conditioner turns on and off repeatedly?


When it comes to short-cycling in air conditioners, it usually means that the unit turns itself off prematurely and then, not long after, turns itself back on. If you notice similar signs with your unit, it could be due to dirty or damaged parts, mechanical or electrical problems.


Why is it harmful for the air conditioner to frequently turns itself off?

If your air conditioning system turns on and off too often, it uses more electricity to get working again and again. This causes parts to wear out much more quickly and serious repairs may need to be made very soon. Frequent repairs and the extra energy the appliance uses will cost you dearly.


On top of that, you won't enjoy quality air conditioning and the constant switching on and off can be disturbing and even disrupt your sleep.


11 reasons why your air conditioner keeps turning on and off, and how to fix it


1. Thermostat problem

The job of the thermostat is to read the room temperature and signal the air conditioner how hard to work. Chances are this element has dead batteries or its electrical connection is intermittent. If you notice that the thermostat screen is blank or faded, change the batteries and check its connection.


2. Improper thermostat location

If the thermostat is placed in an inappropriate location, it may be reading the room temperature incorrectly and therefore also giving wrong signals to the air conditioner.


Here are some cases where the thermostat may be misreading the room temperature:

  • If it is near a window.
  • In cases where it is near a warmer room or appliances that radiate heat.
  • Under vents where there is direct airflow.

To solve this problem, you need to move your thermostat to a more central location.


3. A dirty air filter

This is the most common reason to have an air conditioner problem as a clogged filter does not allow airflow to pass freely. This can also lead to short cycles. This is why you should regularly check and change or clean your air conditioner filters.


4. Dirty condenser coils

The condenser coils are located in the air conditioner's outdoor unit and release heat from inside your home. Their placement is a reason homeowners often forget to check and clean them. If these components of the air conditioner are too dirty, they will overheat and, at some point, the unit may start to shut itself off. So check regularly to see if the coils need cleaning and schedule an appointment for professional air conditioner maintenance.


5. Too big air conditioner

If you've purchased an air conditioner that's too big for your home, it may start shutting itself off right from the start. Since the unit will cool or heat the room quickly, it will shut itself off too often. All of this will reduce the air conditioner's life, lead to higher energy bills, and cause discomfort in use.

It's not worth going through all that, is it? Make sure your air conditioner is properly sized. If you have already purchased an oversized unit, we advise you to replace it with a new one. But before that, consult a professional technician.


6. Refrigerant leak

The refrigerant is a liquid that circulates through a closed system, and for this reason, refrigerant leakage is not normal. If you have a Freon leak, it means that there are small holes through which it is leaking.

Low refrigerant is very dangerous as it is harmful to human health. In addition, the processes in the system are disrupted as it can no longer absorb heat through the coils.

The low pressure caused to the refrigerant leakage will cause the compressor to fail and the system to shut down. When the compressor shuts down, the pressure rises again and the unit turns back on. It is possible that this could cause irreparable damage.

If you suspect you have a Freon leak, be sure to contact a local HVAC company to locate and fix the leak.


7. Compressor failure

When the compressor is overloaded, it begins to run inefficiently, and this can cause the air conditioner to short cycle. If you notice that the compressor shuts off every 2-3 minutes - it is most likely overheating.

This is an important component of the air conditioning system that may be too expensive or even impossible to repair, and you may need to purchase a new air conditioner. So if you suspect that the compressor is overheating, contact an air conditioning repair company as soon as possible.


8. Frozen evaporator coils

Freezing of evaporator coils most commonly occurs when the system is contaminated or a refrigerant leak. Usually, what happens when the coils freeze is that the unit shuts itself off and turns back on after the ice melts.

If you see ice on the coils, check the filters. If they are clean, call a professional to measure the refrigerant level.


9. Electrical problems

You may have an electrical problem in many places in the air conditioning system - the thermostat, electrical connections anywhere in the system, or the circuit boards. You can call an electrician to determine exactly where the fault is.


10. Bad capacitor

The capacitor powers the air conditioner, and if it's damaged, it will likely cause the unit to shut off and turn on unexpectedly after just a few seconds.

Contact a local air conditioning repair company to diagnose and replace the AC condenser if necessary.


11. Clogged drain line

If the water in the system is not draining properly, the float switch will likely trip, and the air conditioner will shut off. If you do not have a thermostat and electrical problem and the air is not circulating, check if the drain line is clogged.

As you noticed, the short air conditioner cycle can be caused by many things, so if you are not sure what is going on, seek professional help.

If you need a new air conditioner, check out Fuji Electric's air conditioners on our website. There you will also find information on the distributors you can purchase them from. Contact us if you need professional advice.