May 16, 2024
Common Problems with AC Compressors and How to Fix Them

When it comes to your home’s cooling system, its compressor is an important part. Situated in your outdoor condenser unit, your compressor is responsible for compressing the refrigerant vapor to remove heat. Unfortunately, just like any other system component, it can malfunction from time to time. Knowing the most common compressor issues can help you to get the problem remedied faster.

Dirty Condenser Coil

As hot refrigerant is pumped outside, it travels through the AC’s condenser coil to release the heat it’s accumulated. If the coil is covered with debris, like dirt and dust, it won’t be able to expel all of the refrigerant’s heat. Your HVAC technician will be able to use an industrial coil cleaner to remove stuck-on debris so that heat from the refrigerant traveling through it can be successfully expelled into the outdoor air.

Refrigerant Leak

Refrigerant is the magic substance that works to absorb heat from inside your home and expel it to the outdoors. This substance is present in your coils and in the suction lines that connect the two coils. Whenever a leak develops in one of these lines or coils, it can greatly reduce the efficiency of your air conditioning unit. Over time, as your AC unit loses its precious refrigerant, it will no longer be able to adequately cool the air in your home.

Lack of Lubrication

Your AC’s compressor unit houses many moving parts. To ensure that they all can work properly, the unit must be adequately and appropriately lubricated. When there is a lack of lubrication, you might hear screeching coming from the compressor as it runs or notice that it only runs for a few seconds at a time before shutting off. Having an HVAC professional perform service on your cooling system in the spring will ensure an adequate amount of lubrication inside your compressor for the upcoming summer months.

Electrical Malfunction

When it comes to your system’s compressor, it can experience electrical malfunctions from time to time. This can be a result of damage to its wires or their contacts. Furthermore, acid can build up where electrical problems happen and cause more damage to your compressor. Scheduling annual cooling system maintenance is a great way to help prevent this issue from occurring.

Worn Out Components

Unfortunately, the components inside your AC compressor aren’t built to last forever. If you hear an unusual noise coming from your compressor, like a screeching or grinding sound, a component may have reached the end of its lifespan. Typical culprits include worn-out pistons and bearings.


Another common issue that can cause your compressor unit to fail is overheating. This can be caused by several issues. Some of the most commonly experienced ones include running too long on dirty coils, low refrigerant, lack of insulation, direct sun exposure, and power surges.

Too Much Refrigerant

Each air conditioning system manufacturer will specify how much refrigerant is meant to go into a particular AC unit. Your unit should not be overfilled with refrigerant, as this can lead to excessive pressure buildup. If pressure levels get too high, they can cause your compressor to prematurely fail.

Outside Contaminants

With your compressor being located in your outdoor condenser unit, it’s exposed to the outdoors. While there is a metal housing on the outside of the unit, sometimes unwanted debris can still make its way inside. Whether it be a leaf, bird dropping, or even dirt, it can drag unnecessary moisture into your system. If left attached to your compressor unit, it can cause corrosion that can prematurely wear out your compressor.

Faulty Capacitor

Your cooling unit’s capacitor is responsible for starting up your compressor. When the capacitor becomes damaged or just reaches the end of its lifespan, it can fail to start the compressor. Fortunately, an HVAC expert can easily replace your capacitor, allowing the compressor to start again so that your system can work as usual.

Malfunctioning Relay

When your air conditioning unit starts up, its relay tells your capacitor that it’s time to give a boost of power to your compressor to get it started. When your relay is malfunctioning, it won’t alert the capacitor that it’s time to do its job. The most obvious sign that your relay is malfunctioning is that your compressor simply won’t start up.

Tripped Circuit Breaker

If your AC unit won’t turn on, you may find that the circuit breaker has tripped. In some cases, your compressor could be causing the trip if it’s overheating or experiencing a similar issue. You can try resetting the circuit breaker once to see if you can solve the problem. If it trips again, you should call in a professional since you likely have a cooling system issue that needs to be addressed.

Expert AC Service

Climate Control provides expert cooling services for the Portland, OR community. We can also assist with all your heating, commercial, indoor air quality, duct cleaning, generator, ductless mini-split, and water heater needs. Simply contact our office today to get the professional AC repair that you need.

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