September 10, 2023

What Causes a Capacitor To Fail in an Air Conditioner?

what causes a capacitor to fail in an air conditioner

Does your air conditioner suddenly quit working on a sweltering summer day? HVAC technicians often find that the unit’s capacitor is to blame for mechanical breakdowns. What causes a capacitor to fail in an air conditioner?

This guide will explain why your air conditioner’s capacitor may break down and what you can do to prevent the issue. With this knowledge, you can keep your cooling system in good working condition. Reach out to experts for reliable AC repair in Hallandale Beach if you are dealing with unexpected mechanical issues. 

What Is an Air Conditioning Capacitor?

Before we dive into what causes a capacitor to fail in an air conditioner, let’s learn more about this critical component. All types of air conditioners contain the same key components, including coils, compressors, and capacitors. Coils and compressors help with heat exchange, while capacitors aid the compressor. 

The capacitor functions similar to a rechargeable battery. Its primary job is to store electricity so the motor and compressor receive an extra boost. Many air conditioners have two types of capacitors:

  • Start capacitor: Helps the motor fan and compressor power on
  • Run capacitor: Provides ample energy to keep the compressor and motor running

What Causes a Capacitor To Fail in an Air Conditioner?

Capacitor failure boils down to three distinct causes. Each of these issues impacts the overall condition of your cooling system, so don’t ignore them if you want to keep your unit running longer. You’ll need professional repairs and, in some cases, air conditioning replacement if the start or run capacitor starts to fail. 


Your air conditioning unit will experience normal wear and tear as it ages. The capacitors will face issues over time, but noticing the damage early is crucial. Experts can fix the piece for a relatively fair price at this stage, whereas extensive damage is harder to repair. 

Keep in mind how old your air conditioner is, and schedule maintenance to monitor the equipment. If you know what causes a capacitor to fail in an air conditioner, you should take the necessary steps to address the issue. 


The hot sun can do a number on your air conditioner. The system can overheat on extremely hot days, especially if it’s located on the roof or in direct sunlight. Capacitors can fail much more easily if the air conditioner is frequently exposed to dangerous temperatures. 

It’s also possible for the unit to overheat just by operating. Constant use will put more strain on the system and make it more prone to overheating, therefore putting the capacitor at risk. 

Power Surges

A sudden power surge that rips through your HVAC electrical systems can damage the air conditioning capacitors. Even if you experience small surges due to fluctuations in the power grid, your capacitors can slowly deteriorate. The air conditioner won’t be able to provide reliable cooling if surges often occur and damage your start and run capacitors.

How To Prevent Air Conditioner Capacitor Failure

Knowing what causes a capacitor to fail in an air conditioner makes it easier to prevent the problem altogether. Normal wear and tear is unavoidable, especially as your system ages. Regular maintenance will keep your system working properly and allow HVAC technicians to examine each piece of equipment. 

Experts recommend scheduling professional maintenance at least once a year to keep your cooling system working efficiently. During these tune-ups, a contractor will detect whether you have a damaged capacitor and perform repairs before the issue worsens. This is a great way to protect your air conditioner in the long run and get the most out of it.

Another way to prevent this issue is to be mindful of how much strain you put on your unit. Overheating is likely on extremely hot days. Protect your system by setting your thermostat a few degrees warmer. You can also use reflective blinds to keep your home cool and energy efficient.

It’s difficult to prevent power surges from damaging your air conditioner in severe weather. Consider investing in a surge protector to minimize damage.  

Contact Local HVAC Experts for Air Conditioner Repairs

Now that you know what causes a capacitor to fail in an air conditioner, reach out to our HVAC contractors with other questions about your cooling system. We’ll give you tips for prolonging the average air conditioner lifespan and help uphold the quality of your unit.

Contact Lion Air Conditioning Cooling and Heating, LLC, at (754) 227-2395 to speak with a specialist or schedule a repair service.