What Causes An AC Compressor To Stop Working

The are various reasons why an AC compressor can fail or stop working. In many cases, the reason why an AC compressor fails has to do with problems that are often preventable.

Fortunately, you won’t have to put up with an AC that is not working for long. Here are a few tips from the experts on how to repair your AC compressor or to prevent any further damages from occurring.

What You Need To Know About AC Compressors

An AC compressor operates in two different ways. It compresses the refrigerant molecules together, and it operates as a type of pump that circulates refrigerant throughout the system. When the refrigerant flows into an evaporator inside a home or office, it works on absorbing the heat inside the building, before turning into gas. From here the gas is heated and squeezed even further by your compressor. The gas then turns into a heated liquid. The condenser coils then cool this liquid down.

When the refrigerant reaches the evaporator, where the cycle repeats, pressure decreases at the point of the expansion valve, which allows the refrigerant to easily absorb the heat before turning into gas. Any damage or leaks to a compressor could interfere with or slow down the process.

Related Read: What is an aircon compressor and how it works?

Reasons Why Your AC Compressor Has Stopped Working

If your heat pump or compressor has stopped working, your first step should involve checking on your power supply. The unit could be unplugged, or you may be faced with a problem that is more serious.

If you are an avid DIYer, you can either examine your AC compressor or contact an AC repair company for a comprehensive assessment. It is important to examine the unit to find the problem. Some of the common issues include tripped circuit breakers, broken thermostats, dirty and dusty air filters, or a blown fuse. Clogged or dirty filters often cause an AC compressor to stop working.

To operate a cooling system correctly, it is important to be realistic when it comes to the temperature you set your thermostat at. For example, if the outdoor temperature is at 110 degrees, avoid setting the thermostat at 65. Your AC unit is not designed for this. It is also important to be aware that a heat pump doesn’t work at optimal levels on freezing or extremely cold days. The unit operates on moving warmed air from one space to another. Once the mercury has dropped under 30 degrees, there is not much heat left for the system to operate with.

Common Reasons Why An AC Compressor Stops Working

Not all AC repair issues are expensive to fix. When you know that is causing the problem with your AC compressor, it becomes easier to work out how much it’s going to cost to repair the unit.

The common reasons why an AC compressor stops working include:

  • Blocked suction lines
  • Dirty condenser coils
  • The size of the suction line is wrong
  • Low refrigerant charge
  • Excess levels of refrigerant
  • Contaminants inside the system
  • Not enough oil lubricant
  • Electrical problems

Before an AC compressor fails completely, they commonly display the following warning signs:

Regular AC maintenance is one of the best ways to fix or catch a problem and to prevent an AC compressor from failing in the future.

How To Tell If Your AC Compressor Issue Is Serious

It is not always easy to make a decision on whether to call a professional HVAC technician to repair your unit or to try and fix the unit on your own. If you are experiencing any of the problems listed below, it is best to rather contact an expert to provide you with a thorough and professional diagnosis:

The On And Off Cycling Becomes More Frequent

This is commonly known as a “hard start”, and is usually caused by electrical issues inside the compressor.

Decreased Cooling

If your office or home is not feeling as cool or cold like it once did, the AC compressor could be experiencing suction issues. This is something best left to the professionals.


Overheating will definitely cause an AC compressor to fail or stop working which is usually caused by motor issues or faulty wiring. If your compressor has stopped working and you start to notice extreme heat or ice, call a professional.

There are many complicated as well as basic reasons why AC compressors no longer work. The ones listed above are just some of them.

Troubleshooting AC Compressor Issues

Has your AC compressor or air conditioner stopped running? While in most cases, an experienced HVAC technician is required for more in-depth troubleshooting, repairs, and, maintenance, here is a list of things to check before you call in a technician:

Check For A Tripped Breaker

Check the service panel for the breaker used for your AC. If it appears tripped, first turn it off, before you turn it back on. This will usually reset your control board, which will get the system operating again.

Test Your Thermostat

Check that the thermostat has been set to the correct temperature and that the batteries are still working. If the settings have been changed it can stop your AC from running.

Listen For A Buzzing Noise

When the system is starting up, go to your condenser unit on the outside of your home or office. If the system is not turning on, and the compressor is buzzing, you might need to replace the start capacitor. A professional technician will need to replace this part since it stores potentially hazardous, and high voltages.

Listen For A Clicking Noise

As your AC compressor engages, there should be a noticeable clicking sound. If you hear repeated clicking or no click at all, or the compressor is not starting, your relay may be faulty. This is another part that should only be replaced by an experienced aircon technician.

Key Take-Aways – Get Helps From Professional Aircon Service Company

AC compressors are one of the most common pieces of equipment that need to be replaced in an air conditioner. If your compressor has stopped working, you want to get it repaired or replace as quickly as possible before your home becomes unbearably hot and uncomfortable. For a quick diagnosis of what is wrong with your unit, call a professional aircon service contractor today! We can help troubleshoot any issues and come up with a plan for repair or replacement so you can stay cool all summer long.

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