What Causes an AC Capacitor to Fail and How to Prevent It

At Best Owner Direct HVAC & Electrical in Cornelius, OR, we know how frustrating it can be when your air conditioning system isn’t working properly, especially during the hot summer months. One common issue that many homeowners encounter is a failing AC capacitor. Let’s dive into what an AC capacitor does, why it might fail, and what you can do about it.

What is an AC Capacitor?

An AC capacitor is a crucial component of your HVAC system. It stores energy and stabilizes voltage to give the necessary jolt to the motors in your air conditioner. Think of it as the battery that helps start and keep your AC running smoothly.

Types of AC Capacitors

• Start Capacitors

Start capacitors provide the initial boost of energy to get the AC motors running. They kick in when your air conditioner starts up.

• Run Capacitors

Run capacitors provide continuous power to keep the AC motors running efficiently. They help maintain a consistent and stable flow of electricity.

Causes of AC Capacitor Failure

Overheating

• Environmental Factors

Capacitors are sensitive to heat. If your AC unit is exposed to direct sunlight or high temperatures, it can cause the capacitor to overheat and fail.

• Electrical Overheating

Running your AC unit for long periods can also cause electrical overheating. This puts extra strain on the capacitor, leading to potential failure.

Power Surges

• Lightning Strikes

Although rare, a lightning strike can cause a sudden power surge that might overload and damage your AC’s capacitor.

• Power Grid Fluctuations

More commonly, fluctuations in the power grid can lead to weaker power surges that gradually deteriorate your capacitor over time.

Aging

• Natural Wear and Tear

Like all components, capacitors have a lifespan. Over time, they can degrade naturally, reducing their ability to function properly.

Symptoms of a Failing AC Capacitor

Hard Starting

If your AC struggles to start or shuts off shortly after starting, it could be a sign of a failing capacitor.

Unusual Noises

• Humming

A continuous humming sound can indicate that the capacitor is failing and the motor is struggling to run.

• Clicking

A clicking noise can also be a warning sign that the capacitor is on its last legs.

System Malfunctions

• Difficulty Starting

When your AC takes longer to start or doesn’t start at all, a faulty capacitor might be the culprit.

• Frequent Shutdowns

If your AC unit frequently shuts down unexpectedly, it’s time to check the capacitor.

Consequences of Ignoring a Bad Capacitor

• Motor Overheating

A failing capacitor can cause the motor to overheat, which can lead to further damage.

• Potential Burnout

If left unchecked, the motor might eventually burn out, requiring expensive repairs or replacements.

• Increased Risk of Total System Failure

Ignoring capacitor issues can put your entire AC system at risk of failure, especially during peak usage times.

Detecting and Diagnosing Capacitor Issues

Visual Inspection

• Signs of Physical Damage

Look for signs like bulging, splitting, or leaking oil. These are clear indicators that the capacitor needs to be replaced.

Professional Electrical Testing

A professional can perform electrical tests to accurately diagnose capacitor issues and determine the best course of action.

Handling AC Capacitor Failures

Importance of Early Detection

Catching capacitor problems early can prevent more serious issues and costly repairs.

Professional Replacement

It’s crucial to have a professional replace the capacitor to ensure it matches your AC’s voltage requirements and is installed safely.

Preventive HVAC Maintenance

Regular maintenance can help catch capacitor issues early and keep your AC running smoothly all year round.

Contact Us

Understanding the role of capacitors in your AC system and recognizing the signs of failure can save you a lot of hassle and money. If you suspect your AC capacitor is failing, don’t hesitate to reach out to us at Best Owner Direct HVAC & Electrical. We’re here to help keep your home cool and comfortable.

For more helpful tips and information, check out our other blogs at Best Owner Direct Blog.