AC Compressor Not Turning On: What To Check

Running into problems with your AC system during the summer is frustrating. If the air conditioning compressor isn’t working properly, it can cause your home or business to become a VERY uncomfortable place.

I have been handling air conditioner repairs in East Dundee, Hoffman Estates, Barrington, Elgin, and all the surrounding areas for years. At first, I worked for a different company, learning the ins and outs of HVAC, before deciding to open Compass Heating and Air Conditioning. Dealing with every aspect of home comfort is important, and your air conditioning is right at the top of the priority list.

What Is The AC Compressor?

AC Compressor Not Turning On: What To CheckThe AC compressor is a vital component of your air conditioning system, responsible for compressing and circulating the refrigerant throughout the unit. It’s found within the outdoor unit, also called the condensing unit, the compressor works in tandem with the condenser coil and evaporator coil to create a comfortable indoor environment.

As the heart of your AC unit, the AC compressor regulates the flow of refrigerant between the evaporator coil and condenser coil. When functioning properly, it helps maintain optimal temperature and humidity levels within your home.

If your AC compressor is not turning on, it disturbs the whole process of your air conditioning system. If you find that your AC isn’t working properly, here are a few things you can check out:

How To Troubleshoot AC Compressor Issues

There are several common issues that can affect the performance of your AC compressor. It’s not always as evident as you’d hope to find the issue with your AC system. In this section, we will discuss different problems and their potential solutions to help you troubleshoot and maintain your HVAC system.


One of the most common causes of AC compressor issues is low refrigerant levels. When the refrigerant level drops, the compressor may not turn on, or start blowing warm air or hot air instead of cold, comfortable air.

To check the refrigerant levels, use a refrigerant gauge to measure the pressure in the system. If the levels are low, you may have a refrigerant leak. In this case, consult a professional HVAC technician to locate and repair the leak and recharge the system.


Faulty valves within the compressor can lead to problems with the AC system. Malfunctioning pressure switches or winding problems in the motor can cause the compressor to stop working or struggle to turn on. If you suspect valve issues, contact a qualified technician to diagnose and repair the problem.

Read More: The Costs Of Replacing An AC Condensor 

Dirty Coils

Dirty condenser and evaporator coils can significantly impact the efficiency of your air conditioning unit. The dirt can act as an insulating layer, preventing the coils from effectively transferring heat. Regular maintenance, including cleaning the coils, can prevent this issue and improve the performance of your AC system.

Blocked Lines

Blocked refrigerant lines can cause your compressor to overheat and eventually fail. To prevent this, make sure to inspect the lines regularly and clear any debris or obstructions. A professional HVAC technician can also help flush the lines and check for any leaks or damage.

System Keeps Shutting Down

If your AC system keeps shutting down, it could be due to a malfunctioning blower motor or fan. The fan is responsible for distributing the cold air throughout your home or business, and if it’s not working correctly, the compressor may overheat and shut down.

With regular maintenance,a professional will check the fan and motor. Instead of worrying about inspecting these yourself, we recommend letting an experienced HVAC technician take a look.

AC Compressor Tries to Turn On But Won’t

If your AC compressor tries to start but won’t, it may indicate a dead compressor or an electrical issue. In this case, it’s essential to consult a professional technician to diagnose the problem and determine if the compressor needs to be replaced or if there’s a component that can be repaired or replaced.


Overheating can cause the AC compressor to stop working and may even lead to permanent damage. Factors contributing to overheating include low refrigerant levels, dirty coils, blocked lines, or a malfunctioning fan. Regular maintenance of your HVAC system can help prevent overheating and prolong the life of your compressor.

When to Call A Professional

AC Maintenance Guide: A Comprehensive ChecklistAs you can see, most of the solutions include calling an HVAC technician for professional help. Dealing with these components can be confusing, and the last thing you want to do is cause additional damage to a system that can be fixed easily by a professional.

Homeowners can safely check items like the power supply, air filter, or any obvious, visible problems. But, you need an HVAC professional to dig further into the system.

A certified AC technician has the expertise to troubleshoot more complex problems and work inside the unit without breaking anything else. This is especially so for compressor replacement, which is a large job with many different factors to consider.

Air Conditioner Maintenance

The best way to ensure that your air conditioner is operating properly is to schedule regular maintenance. As a part of the service, someone will inspect your compressor and make sure that it’s running in tip-top shape.

We recommend air conditioner service at least once a year, preferably before the summer. If you don’t get to it before the summer, anytime during the season works as well. AC service keeps your system operating efficiently and prolongs the system’s lifespan. Make sure that you schedule regular service to get the most out of your AC!


How do I reset my AC compressor?

To reset your AC compressor, first turn the power off to your AC system. If there is a reset button on the outside of your compressor, press the button for several seconds and release it. Once reset, turn the power back on and see if it works.

How do I know if my AC compressor is blown?

To know if your AC compressor is blown, consult a professional HVAC technician. If you reset your air conditioner and it still isn’t working, you know it’s at least time for a fix.

Why is my compressor not kicking on?

If your compressor is not kicking on, it could be an electrical problem, or an issue with the fan or motor. We recommend contacting a professional if your AC compressor is not working properly. AC repair services in Algonquin, IL.

Call Compass Heating and Air at (630) 504-8688, for AC repair services in Algonquin, IL.