9 Reasons Why Your Air Conditioner Starts Then Stops Quickly [FIX IT]5 min read

by Ben | Last Updated: April 7, 2022


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When your air conditioner keeps turning on and shutting off after a few minutes, it’s called short cycling.

The cause of short cycling is usually some damaged part or poorly maintained unit. It happens there’s an electrical issue as well.

An air conditioner that turns off after a couple of minutes is what I call “walking dead” because it’s just a matter of time until your whole AC system will be damaged.

You need to act fast to fix these kinds of issues that are causing short cycling.

Once you fix it, you’ll notice how your electricity bills will “magically” drop.

Here are the main causes of short cycling:

9 Reasons Why Your Air Conditioner Starts Then Stops After A Few Seconds

1. Refrigerant problem

From what I’ve seen, this is one of the most common problems when your air conditioner stops after a short time.

Refrigerant is responsible for cooling down the air inside of your home while absorbing the heat and pushing it outside.

Low refrigerant levels are usually due to small leaks that shut off your compressor automatically because of low pressure.

When there are refrigerant leaks, your AC will start making weird noises.

It’s not good either when your AC turns back on because the compressor has shut down, so the pressure rises again and allows your AC to turn on.

Not dealing with refrigerant leaks immediately will ruin your whole cooling system after some time, so it would be smart to contact professionals.

2. Oversized unit

If you recently bought a new air conditioning system, and you notice that your AC suddenly shuts off – you probably bought a bigger unit than you actually need.

The problem is that your unit will cool your home much faster and once it reaches the desired temperature, it will shut off quickly.

It’s important that you know ways to save money on your air conditioning.

You might think this is an advantage for you, but in reality, it will bring you higher electricity bills, more often repairs, and definitely a shorter lifespan of the unit.

3. Thermostat problem

At first, you might think that the thermostat is not an important part of your unit, but I thought the same thing and I was making a big mistake.

The thermostat is responsible for controlling the whole temperature inside of your home. It signals the heat pump to regulate the temperature, so this is why it’s important that our thermostat works perfectly.

When the thermostat isn’t working properly, it won’t send the right signals to the air conditioner’s system – that’s why your AC starts and stops after a couple of minutes.

I’ve noticed that the brightness of the thermostat screen will usually decrease, it’s probably low on battery and you need to replace the batteries.

4. Bad thermostat placement

If you hired a professional to install your thermostat, they would never place it in the following places:

  • Near a window to expose it to daily sunlight
  • Near higher-temperature rooms in your house such as the kitchen or bathroom
  • Below the air conditioner to constantly receive cool air

If your thermostat is placed near places like this, I’d suggest moving it somewhere else.

The problem here is that your thermostat will receive a “fake” temperature and send the wrong signals to the unit.

5. Bad air filters

This is a common mistake and we’re all guilty of it because of our laziness.

If you’re someone who hasn’t maintained your air conditioner in a long time, you should go ahead and clean your air conditioner immediately.

When dirt and dust collect in your air filters, it will be less efficient and the airflow won’t be near as good as before.

6. Frozen evaporator coils

When you’ve made sure there isn’t any problem with your thermostat or filters, it might be that evaporator coils are frozen.

This issue is strongly connected to low refrigerant and dirty condenser coils.

You should unfreeze your air conditioner first, and if it doesn’t fix the problem – you should seek professional help.

Additionally, you will need to clean condenser coils if they’re full of dirt and grime. They’re located on your outdoor AC unit.

📍 Tip: Use the best AC Coil Cleaner to remove any dirt or dust within seconds.

7. Broken compressor

When your compressor is broken or starts overheating, your AC will shut off more frequently and start again once the compressor is cooled down.

The best solution is to replace the compressor immediately.

The biggest problem, if you don’t fix the compressor, is that it will slowly damage your other AC’s parts which will result in an overall shorter lifespan.

8. Electrical problems

When you’ve made sure you’re not dealing with any of the problems above, you’re probably dealing with electrical issues.

It could be bad wiring from the thermostat or circuit boards.

I had electrical issues and the electrician confirmed it was causing short cycling.

As I don’t have a lot of experience with electricity, I would recommend you to call a professional as he will be able to fix it for you immediately.

9. Run capacitor problem

The role of a run capacitor is to transmit the energy to the air conditioner, so it can turn on and keep cooling your home.

When the run capacitor gets broken, it can no longer transmit the same amount of energy as when it’s brand new.

The lack of energy causes your air conditioner to turn off after a minute or so.

If you have a warranty on your AC, contact the company and ask them for the same run capacitor model.

Use these 9 reasons as a checklist when you start inspecting your air conditioner.

Also, don’t forget to act fast before your whole AC system gets damaged.

Benas Leonavicius
Hey there! I am Benas, the founder of Home Caprice. Thanks for reading the article, I hope you were able to find what you were looking for. Me together with my team, are here to simplify heating and cooling for everyone. If you want more details about the website and our team, please check the about page.