What is the Most Common Part to Fail on an AC Unit?

Air conditioning systems work hard to keep homes and businesses cool, but over time, certain components are more prone to wear and failure. If you find yourself needing AC repair in Concord, CA, chances are one of these common parts has malfunctioned. Understanding which parts fail most often can help you recognize early warning signs and seek air conditioner repair before small issues turn into costly breakdowns.

In this blog, we’ll explore the most frequently failing AC components, why they fail, and how to prevent issues from occurring.

The Most Commonly Failing AC Parts

Capacitors

Capacitors are among the most frequently replaced parts in an AC system. They store and release electrical energy to help start the compressor and fan motors. When a capacitor fails, the AC unit may struggle to turn on or fail to cool properly.

Signs of a failing capacitor:

The AC unit won’t start or takes longer than usual to turn on
A humming noise comes from the outdoor unit
The system cycles on and off frequently
Warm air blows from the vents instead of cool air

Replacing a capacitor is a relatively inexpensive AC fix, but ignoring the problem can lead to further damage, especially to the compressor.

Compressor

The compressor is the heart of your AC system, responsible for circulating refrigerant between the indoor and outdoor units. It’s also one of the most expensive parts to replace.

Why compressors fail:

Low refrigerant levels cause overheating
Dirty coils force the compressor to work harder
Electrical issues can short out the compressor
Lack of maintenance leads to system strain

If your compressor fails, a technician may recommend air conditioning installation rather than repair, especially if your unit is older.

Fan Motor

Your AC unit has at least one fan motor, and possibly two—one for the condenser (outdoor unit) and one for the blower (indoor unit). These motors help circulate air and dissipate heat.

Common reasons fan motors fail:

Lack of lubrication causes overheating
Dirt and debris clog the motor
Electrical failures prevent operation

If your fan motor isn’t working, you might hear strange noises or notice weak airflow. Addressing this issue quickly with an air conditioner repair service can prevent strain on the rest of the system.

Refrigerant Lines & Leaks

Refrigerant is crucial for cooling, and any leaks in the system can lead to serious performance issues. If your AC unit isn’t cooling properly, low refrigerant levels might be the culprit.

Signs of a refrigerant leak:

Warm air blowing from vents
Ice buildup on refrigerant lines or coils
Hissing noises from the system
Increased energy bills due to inefficiency

Since refrigerant leaks require specialized handling, it’s important to contact heating and cooling contractors to safely repair the air conditioner.

Evaporator & Condenser Coils

Coils are responsible for heat exchange in your AC system. The evaporator coil absorbs heat from indoor air, while the condenser coil releases it outside.

Why coils fail:

Dirt and debris buildup reduce efficiency
Corrosion from moisture exposure
Refrigerant leaks cause freezing and damage

Regular maintenance, including coil cleaning, can extend their lifespan and prevent costly aircon repair.

Thermostat

A faulty thermostat can cause temperature inconsistencies and prevent your AC from running efficiently.

Symptoms of a failing thermostat:

The AC doesn’t turn on or off correctly
Uneven temperatures in different rooms
The thermostat display is unresponsive

Sometimes, a thermostat issue is a simple air conditioner fix, but in some cases, upgrading to a smart thermostat can improve efficiency and performance.

How to Prevent AC Part Failures

Preventative maintenance is the best way to avoid unexpected breakdowns and costly air conditioner repair. Here are some tips to keep your system running smoothly:

Change air filters regularly – A clogged filter restricts airflow and strains components.
Schedule annual maintenance – Professional inspections can catch small problems before they escalate.
Keep outdoor units clear of debris – Leaves, dirt, and obstructions can reduce efficiency.
Monitor refrigerant levels – If you notice weak cooling, have a technician check for leaks.
Listen for unusual noises – Strange sounds can indicate worn or failing parts.

When to Consider AC Replacement

If your unit is constantly needing air conditioner repair service, it might be time to replace it. Some factors that indicate air conditioning installation is the better choice include:

Your AC is over 10-15 years old
Repairs are becoming more frequent and costly
Your energy bills are steadily increasing
The system no longer cools effectively

Investing in a new, energy-efficient system can lower operating costs and reduce the need for frequent aircon repair.

Essential Guide to AC Repair & Installation in Concord, CA

For more in-depth information on keeping your AC system in top shape, check out our Essential Guide to AC Repair & Installation in Concord, CA. This guide provides insights on common AC problems, choosing the right technicians, and determining when to repair or replace your unit.

Contact Us for AC Repair in Concord, CA

If you’re experiencing issues with your AC unit, don’t wait for the problem to get worse. Our expert technicians provide reliable repair air conditioner services to keep your home cool and comfortable. Call us today at 925-755-4440 or send a message through our website to schedule your service.