6 Common Causes of AC Compressor Failure

6 Common Causes of AC Compressor Failure [2022] Phyxter Home Services

⭐ What Causes AC Compressor Failure?

In the same way, as we need our air conditioning unit to keep us cool during the boiling summer months, your air conditioner needs a functioning compressor to do its job properly.

In the event that a compressor suddenly gives out on a hot day, you will immediately become aware that your air conditioner is no longer producing anywhere near enough cooled air.

Failing to find the root cause can cause catastrophic failure of your AC and its components.

The reasons that a compressor can malfunction are numerous.

However, before we look at some of the most common ones, it is worth stopping for a minute to understand why the AC compressor is such an important component of a cooling system. 

🙋 NOTE: The same information in this article can be applied to Heat Pumps.

⭐ Air Conditioner’s Compressor – What Is It?

ac compressor cycle

Of all the parts that make up an air conditioning system, the compressor is probably the most important.

Here are a few basic points that you should know before reading the rest of this article:

The compressor is responsible for driving the refrigeration gases around the refrigerant lines.

Without it, you will have no cool air.

Compressors are quite durable and tend to last 15-20 years before they need replacing.

However, if you do not maintain it, the compressor may break down before this.

It is unwise to attempt to repair or replace a compressor without prior air conditioning experience.

Due to the delicate nature of an AC compressor failure, you should always call on the services of a licensed HVAC professional.

Checking AC Compressor

⭐ Common Causes of Compressor Breakdown

Now that we have clarified the crucial role of the air conditioner compressor, it is time to look at a few common reasons why they can malfunction.

🛠️ Dirty Coils

Dirty AC Evaporator Coil

As time passes, dust and dirt will naturally accumulate on an AC unit’s condenser coil.

This dirt can inhibit the efficiency with which the coil can perform heat transfer, meaning that the system has to expend more energy to reach the temperature dictated by the thermostat.

When heat cannot escape, and the system is put under extra strain, the compressor tends to overheat and break down.

If you notice that your AC unit appears to be laboring, it is a good idea to clean the coils using special cleaning foam to see if this resolves the issue.

Replacing the air filter regularly helps protect the evaporator coil from accumulating dust and allows for better air flow over the coil.

🛠️ Insufficient Refrigerant Charge

Phyxter HVAC technician checking refrigerant charge

AC compressors produce cool temperatures by pumping a refrigerant gas called Freon around a series of refrigerant lines. 

Refrigerant lines are sealed systems, and refrigerant levels should remain constant.

However, it may sometimes be the case that a refrigerant line develops leaks, which allows the refrigerant to escape.

When this happens, the system will overheat and sometimes cause your ac compressor to malfunction.

If you suspect that your system has a refrigerant leak, you should call an HVAC professional to take a look straight away.

Unattended refrigerant leaks can damage your AC unit and are difficult to fix without experience.

🛠️ Electrical Malfunctions

AC compressor failure caused by electrical malfunction

No electrical system lasts forever, and the same can be said for the circuit board and wiring in an AC unit.

Over time, acids and oxidation will build up and eat away at the contacts in the circuits and cause a power failure.

In the end, this will prevent power from reaching the ac compressor, causing it to shut down suddenly without much warning.

Unless you are a trained electrical engineer, you will struggle to diagnose and repair an electrical malfunction.

On the other hand, an experienced HVAC technician can quickly replace the offending wire or circuit board for a reasonable price.

🛠️ Clogged or Damaged Suction Lines

testing AC suction lines

Another issue that can cause sudden compressor breakdown is problems with the suction lines.

When refrigerant lines get older, the constant change in temperatures they are subjected to throughout their lifespan can cause them to develop cracks and holes.

Damaged lines can prevent the compressor from moving refrigerant around the system freely, reducing your system’s cooling capacity.

This puts additional stress on the compressor motor as it’s working hard trying to pump enough refrigerant through the system and will often result in an eventual breakdown.

If you notice that your system is struggling to produce cool air, it Is worth having an HVAC technician come and check the suction lines for damage.

If they find anything, they can replace the lines and top the system up with Freon.

🛠️ Inadequate Lubrication

AC Compressor failure caused by inadequate lubrication

Just like with any other motor, your compressor motor requires lubrication to keep all of its moving parts running smoothly.

In the event that your compressor motor is forced to run without being serviced with oil, it will not be long before it has worn out and needs replacing.

You can often add lubricant to a compressor motor without prior AC knowledge or training.

Find the oil lubricant entry point on your compressor and add some of the same type of lubricant as recommended in the unit’s instruction manual (be careful not to overfill and check the lubricant levels while filling).

However, if the motor in your compressor wears out before you have a chance to do this, you will need the help of a professional to install a new one safely.

🛠️ Contaminant Infiltration

Best Location for AC Outdoor Unit

If your house uses a central air conditioning system, the compressor will usually be located in the external unit outside your home or on the roof inside the condenser coils.

Unfortunately, exposure to the elements for prolonged periods gives ample opportunity for contaminants such as dust, dirt, leaves, bird droppings, and soot to find their way into your AC unit.

If this debris gets into the compressor, it may cause a malfunction.

To prevent contaminant infiltration, you should take care to clean the area around the external unit as well as inside it.

This routine should be performed every couple of months or so as part of a regular maintenance routine.

Dealing with other common AC problems? Check out: Top 18 Common AC Problems and Solutions.

⭐ Conclusion

Phyxter Approved Logo on Service Truck

AC compressor failure can be common and expensive if you fail to take care of your AC throughout its life span.

Understanding what could cause ac compressor failure can help your AC run efficiently and keep you and your family cool when you most need it.

A happy air conditioner is an inexpensive air conditioner! 

Air Conditioner repair is best left to the experts though if you think you can give DIY a go, here’s a great article on DIY AC Repair.

Contact Phyxter Home Services when you need an air conditioning professional to fix your HVAC system if it isn’t cooling how it’s supposed to.

Check out our page on Air Conditioning Services for more information or a free estimate in your area. We have highly trained professionals that are experts at air conditioning repair and can get your AC up and running in a jiffy.

Looking for a new replacement filter? Check out our next article and choose the right filter for your home: Air Filter Guide. MERV Filter Ratings and What They Mean For Homeowners.

Want to learn more about your home’s AC system? Feel free to check out our other Air Conditioning articles!

Jake Gibson

CEO @ Phyxter and HVAC Guru

About our blog

Phyxter (pronounced Fix-ter) is a national home services brand specializing in Residential HVAC, Electrical and Plumbing solutions.

Phyxter is laser-focused on writing the best articles and guides to empower homeowners to get the best out of their homes.

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