Air Conditioner Turns On and Off Right Away

AC turns on and off

A clear sign of trouble in your air conditioner is if it short cycles, or turns on and off unexpectedly. It might give you a headache, especially if it happened during a particularly hot day. Don’t worry because this might be a simple problem you can fix yourself. If not, your HVAC contractor will be there to help you out.

Some Problems You May Solve Yourself:


Some settings with your thermostat might be causing your air conditioner to turn on and off. Check its timer and change it to suit your needs. You should also replace its batteries if the screen appears blank.

Air Filter

A common trouble that causes short cycling is a dirty and clogged air filter that needs some cleaning. Turn your unit off and clean the filter or replace it if needed.

Evaporator coil

Sometimes, the evaporator coil gets dirty or covered with ice. That will make it hard for it to process the air; and might shut down the system. It is simple enough to clean it up. To melt the ice, turn off your system for at least 24 hours, dry it up, and turn it back on.


The most exposed part of your unit is the condenser. You have to check it from time to time, and trim foliage near it so nothing will restrict its airflow. If something blocks it, it might cause the whole system to short cycle.

Bad Capacitor

It is relatively easy to spot a bad capacitor and replace one. You will be able to easily tell this if the short cyclings are accompanied by humming noises. You can purchase an identical capacitor with the correct voltage rating and capacitance to suit your air conditioner.

Problems that Require the Help of A Professional:

Electrical Parts

Some trouble with the electrical parts may also cause short cyclings. You need to ask an expert to check wirings, circuit boards, and others.

Oversized Air Conditioner

A unit too large for your system will work ineffectively. It will cause insufficient cooling and will turn off unexpectedly, as it will cool the place quickly but unevenly. Before installing a new air conditioner, consult your HVAC contractor so you can get the perfect one for your system and house.

Low Refrigerant Level

Refrigerant level goes down after using your air conditioner for several years. Your technician may detect this problem on regular services. If not, you may contact them to recharge it for you.
It can also go down because of a leak, which is highly unsafe. You will know if your unit makes loud screaming noises. Turn it off immediately and call an expert to fix it.
Low refrigerant level causes your unit to short cycle and work inefficiently as heat cannot be absorbed.

Broken Thermostat or Remote Control

Your thermostat might be broken if it still won’t function even if you get new batteries. This is, unfortunately, not an easy fix for you. It will make your air conditioner turn on and off unexpectedly.
The same goes with a faulty remote. It is best if you call a technician to fix it

Some problems might be easy for you, but some might not. Make plans with your contractor to avoid unexpected problems and emergency costs. Do not hesitate to call one to help you!