COVID
Dear Clients, please note that all bookings will only resume after the COVID shutdown period.
Common Problems

10 Reasons Why Air Conditioner Turns On and Off

What's in the article?

Common Issues

What to Do if the AC Won’t Stay On

Turn to the Aircon Repair Experts

On those warm, summer days, an air conditioner really helps in keeping you cool while you go about your day. During nights, the AC provides you the comfort for a blissful sleep.


The air conditioner is a modern invention that has made home life more comfortable, which is why we homeowners take great care in maintaining it. However, even the most experienced homeowners would find themselves in frustrating situations when their air conditioner turns on and off in what is called short cycling.


Whether it is an indoor or outdoor AC unit turning on and off, a variety of issues can cause problems in your cooling system. Here are 10 of the most common reasons why AC units malfunction, and how to fix them.


Air conditioner control panel
The issue may be with the thermostat location instead of the AC unit.


1. Thermostat Location

The thermostat tells you the temperature of the room, but sometimes readings can vary per location. Placing your thermostat in a warmer or cooler place than the rest of the room can give you inaccurate readings. The air conditioner turns on and off repeatedly to make up for the imbalance in the thermostat reading.


Most likely, the issue is not that your AC won’t stay on, but the unit is trying to adjust the temperature to match the readings of the thermostat.


2. Refrigerant issues

Refrigerant is the cooling liquid that absorbs warmth from the air and provides the room with cool air. If your AC turns on and shuts off repeatedly, it may be because of a leak as low refrigerant levels cause the compressor to malfunction with the low pressure. When the unit is off, the pressure builds up again, the compressor powers up, and the cycle continues.


Contrary to popular belief, refrigerants in AC units don’t evaporate or run out unless there’s a leak. So if you frequently see your refrigerant levels on low, you might want to have a professional service check your unit for any cracks or holes.

3. Cooling System is Too Big

Is this problem happening to your newly installed unit? It may not be a problem with your AC unit at all, but rather with the size of your cooling system in relation to the size of your room.


A higher horsepower may cool down your space a lot faster, but is a factor when the air conditioner turns on and off right away. Your cooling system might be too big for your room, as the AC quickly cools down the room, and then shuts off once it reaches the desired temperature.


Consider moving the unit to a larger room, or replacing the unit with a smaller one. You can work with your maintenance provider to assess the proper horsepower you’ll need for the size of your room.


Modern living room with split-type air conditioner
AC units are dependent per location in terms of cooling power.

4. Airflow Issues

When airflow is restricted, the warm and cool air cannot properly circulate enough to cool down your room. The AC then becomes faulty and cannot perform as intended, causing the unit to short cycle.


Airflow issues may be caused by clogged drain pipes, frozen compressor coils, dirty air filters, and more. Talk to your maintenance provider to assess the source of the problem so you can find a solution to fix your AC issues. 

5. Busted thermostat

Check if your thermostat is functioning well. The thermostat is the main component of your entire AC unit that controls the temperature and fan, and a faulty thermostat provides inaccurate temperature readings that can mess up the cooling system.


Check if the batteries are running out, or if the thermostat itself has started to fail. Your AC issues may be fixed with something as simple as changing the batteries on your thermostat or remote control. 

6. Dirty condenser coils

Dirty or rusted condenser coils can restrict airflow and cause problems with cooling the air. If your air conditioner turns on and shuts off repeatedly, it might be due to frozen condenser coils that get icy. The AC unit shuts off when the ice is thick, only to turn back on when the ice melts.


To clean your condenser coils, you will need to look for professional cleaning services that can refresh your condenser coils to their original state.​​


Technician soldering circuits on electrical board
Electrical problems can be caused by faulty wiring, loose connections, or short circuits.

7. Electrical Problems

With new and cleaned units, the issue may lie with the electrical wiring which can cause air conditioner short cycling. The internal circuit boards may be faulty, or there might be a misconnection in the wiring of your unit and thermostat.

8. Capacitor Issues

Along with electrical problems, the capacitor may have been overloaded. A faulty capacitor cannot provide your AC unit with the initial power boost it needs to function properly. 


You may need to replace the capacitor if you notice your air conditioner turns on and off right away after a few seconds.

9. Dirty Air Filter

A dirty air filter can restrict air flow, causing cooled air to ice your unit. Similarly to the problem with dirty condenser coils, when the filter is clogged, the air conditioner turns on and off right away when ice forms or melts. 


Make sure to clean your air filter with a little soap and water at least twice a week to prevent issues with your AC unit.

10. Compressor Failure

Compressor failure can sometimes be caused by a refrigerant leak, but is still damaging just the same. Your AC compressor may be starting to overheat, break down, or malfunction, which is causing your unit to shut off repeatedly. 


Air conditioner compressors can become faulty from regular wear and tear, and you will need to contact your brand’s servicing company or a professional repair firm to replace the compressor.

Modern bedroom with black walls, grey bed, and split-type air conditioner
Summer nights are more comfortable with a working air conditioner.

What to Do if the AC Won’t Stay On

If you’ve tried to diagnose the problem, but you still have the problem of your air conditioner turning on and off repeatedly, then it’s time to call in the professionals.


Professional cleaning services are not only essential in aircon upkeep, but they can save you from further damage that may be costly. For more serious issues, a professional will be able to diagnose and repair the problem properly, allowing you to enjoy your AC unit longer.

Turn to the Aircon Repair Experts

Luce Aircon consists of seasoned professionals who will be with you through your entire AC journey, from installation and cleaning, to maintenance and repair. As a trusted aircon servicing company in Singapore, we cater to all types of aircon units across different brands.


Call or drop us a message today to book an appointment.

4.5
203 reviews
All our happy customers can’t be wrong! Let us take care of your home cleaning need.
Book Now

For More Tips & Tricks

Oops! Something went wrong while submitting the form.

Staff Writer

Staff Writer

This article is written by our passionate staff writers who seek to share our knowledge from our business

Related Articles

Let's talk

Book Service
Thank you! Your submission has been received!
Oops! Something went wrong while submitting the form.