#Home Improvement

Compressor Problems: Fixing An AC Compressor Not Turning On

Air conditioners are supposed to keep your house cool and comfortable. It can be frustrating to find out that your compressor is not turning on at the last minute. As a result, you have to deal with hot air coming from the vents or the air handler if it’s a ductless air conditioner. But there is no need to panic. Here are some tips that will help you troubleshoot your compressor issues. Let’s begin.

Low Refrigerant Level

This is perhaps the most common issue when it comes to the AC compressor not turning on. Most people are not aware of the fact that compressors operate based on a certain refrigerant level. This means if the refrigerant level is low, the compressor will struggle to perform at its peak.

In old air conditioners, low refrigerant is due to cracks, rust, or other damages. However, in the case of new air conditioners, it is mostly due to improper installation. Furthermore, inspecting and ensuring proper refrigerant levels is a crucial part of regular maintenance.

If your air conditioner is maintained by a professional, you should not be worried about the refrigerant level going low due to leakages or cracks. But if your compressor does not turn on or is tripping regularly, it means the refrigerant level is low. You will need to get it refilled by an expert.

Dirty Filter

Believe it or not, a dirty or clogged air filter can also prevent the compressor from turning on. Even though an air filter is commonly assumed to be a minor component but plays a huge role in terms of smooth performance of the air conditioner.

If the air filter happens to be clogged, the airflow will be impacted. As a result, the evaporator coil will end up being frozen and the refrigerant’s pressure will drop significantly. In this case, the compressor will be turned off because the low-pressure switch detects the low pressure of the refrigerant and it cuts power to the compressor.

To solve the issue, you will either need to clean the air filters or simply replace them if due.

Dirty Condenser Coil

You might be thinking that solving a simple compressor issue would be easy and straightforward. You need to keep in mind that every component inside an air conditioner works as a team to produce and distribute hot and cool air.

Similar to humans, air conditioners too fail to perform if a certain component fails to deliver. This is why mentioning the condenser and evaporator coils is important. While the evaporator coil is one thing, the condenser coil is another.

The condenser coil helps dissipate heat. However, if there are layers of dirt and dust accumulation, it makes it much harder for the coil to dissipate heat. As a result, the coil gets overheated to the point where the refrigerant pressure reaches an extremely high level resulting in the high-pressure switch to cut the power off.

Electrical Problems

If none of the issues mentioned previously are the cause, you should shift your attention to electrical problems. A compressor not turning on might be due to a bad capacitor, fuse etc. Then again, you should not play around with such things as you can get electrocuted.

Consult an expert who will determine the root cause of the problem. In addition to being electrocuted, you might end up damaging a component that is expensive.

Dormancy Issue

If your AC compressor is not turning on, you should check the fan to see if it’s working. If the fan fails to turn on, it could be a dormancy issue. This usually happens when the air conditioner has not been used for a while and layers of dirt and dust accumulation prevent the fan from rotating.

You can try starting the fan manually if you are aware of the basics. Plus, try cleaning the fans to see if they turn on automatically. If not, you will need to consult HVAC repair services Smithtown.

Thermostat Malfunctioning

Thermostat malfunctioning is a common issue as well since it is an electric component. A malfunctioning thermostat is a problem as it directly influences the performance of your air conditioner. If you observe that your air conditioner is acting unusual instead of calling an expert right away, you should check the thermostat.

If you have installed an aftermarket thermostat, it could be that the batteries are gone and need to be replaced. However, if that is not the issue, it means the thermostat needs calibration. And even if that does not solve the problem, your thermostat will be needing a replacement.

Tripped Circuit Breaker

If the circuit breaker has tripped, the air conditioner will fail to turn on. So, this is another issue you need to consider if your air conditioner fails to turn on. A circuit breaker acts as a safety tool preventing the air conditioner from being damaged if there is a power surge.

All you need to do is locate the circuit breaker and turn it on. However, if your air conditioner is tripping the circuit breaker, it means there is an electrical problem somewhere. Avoid trying to fix this yourself and call an electrician who can look at the circuit breaker and determine why it’s tripping to solve the issue.

Malfunctioning Compressor

Finally, if the air conditioner you own is several years old, it most likely means the compressor’s lifespan is up. Compressors are tough and rigid components but come with a timespan after which you should replace the air conditioner.

As a general rule of thumb, if the air conditioner happens to be 10 years or older, you should replace the entire unit. There is no point in replacing the compressor as there will be no guarantee it will work for long. Moreover, if the compressor is making strange noises, you should know that it’s dying on you.

In the case of a new air conditioner, the warranty will cover it but if it’s a few years old, you will need to pay for the replacement. In most case, buying a new AC unit is better than replacing the compressor.

What Can I Do To Prevent Compressor Problems?

The best way to prevent compressor and other expensive problems is to schedule professional air conditioner maintenance. Depending on the usage frequency, you should get your air conditioner maintained by an expert at least once or twice a year.

Professional maintenance does not only include cleaning but also ensuring proper refrigerant levels and smooth operation of the components. Some minor problems, such as cracks and leakages, go unnoticed until they turn serious.

However, a professional is able to spot them. This helps solve the issue before you end up with expensive repairs and replacements. What this also means is that instead of assuming it as an expense, you should think of it as an investment.


In conclusion, an ac compressor not turning on could be due to several reasons. The important thing is that you should be aware of some important tips that will help you kickstart the process. Make sure to inspect the air conditioner and keep it clean regularly. Plus, have air conditioner repair services Stony Brook on your side if the issue seems complicated.