Air conditioners run on electricity, but they don’t receive power by simply plugging in a cord. Instead, capacitors are located in various parts of your system that provide an extra “boost” of power to the components that consume the most energy during every cooling cycle. Occasionally, those capacitors can blow out and prevent your air conditioner from operating properly. Today we’re going to talk about what happens when your air conditioner has a blown capacitor, how to identify a blown capacitor and how the problem can be solved!

What is a capacitor?

A capacitor is a device that is designed to store energy and provide it to your air conditioner during every cooling cycle. Capacitors are located near the motors for your system’s compressor, air handler, and outdoor fan.
When a cooling cycle begins, the start capacitors are used to provide an extra boost to those motors to help them start up right away. After each motor is running adequately, the start capacitors turn off and another set of capacitors, the run capacitors, are used to continuously provide extra energy whenever the motors need an extra boost. This helps ease the load on your air conditioner’s various motors while allowing them to run consistently.

What causes a blown capacitor?

Several things can cause a capacitor to blow, including:

  • A power surge or lightning strike.
  • If your home is struck by lightning or encounters a power surge, the surge can overwhelm your capacitors and cause them to blow.

  • A short circuit. If there is a short circuit in one of your air conditioner’s electrical components, any one of your capacitors can be affected.
  • A short circuit. If there is a short circuit in one of your air conditioner’s electrical components, any one of your capacitors can be affected.
  • Normal wear and tear. Capacitors can fail overtime due to old age and normal wear and tear.

What are the signs of a blown capacitor?

  • A burning smell.
  • Whenever an electrical component overheats, it tends to give off a burning smell. This can happen when your capacitor is overheating.

  • Hard starts. A hard start is when your air conditioner stutters while it’s trying to turn on and eventually fails to begin a cooling cycle. Blown capacitors are the number one reason for hard starts in an air conditioner.
  • A humming or clicking sound. When a capacitor is starting to die, it will often produce a clicking sound. If a capacitor is completely blown, your air handler or outdoor unit can start giving off a humming sound.

How can a blown capacitor be fixed?

Fixing a blown capacitor is as simple as swapping out the busted capacitor for a new one. This is a job that should only be performed by a professional technician who is adequately trained to replace the part. If you notice any of the symptoms of a blown capacitor that we listed above, contact Jerry Kelly Heating & Air Conditioning right away so we can send someone to your home to fix the problem before it causes other issues with your system.
If you have any questions about a blown capacitor in an air conditioner, or if you’d like a cooling system serviced or installed in your home, contact Jerry Kelly Heating & Air Conditioning, your St. Charles, MO, air conditioning contractor. We provide service all over the St. Louis area, including towns like Weldon Spring, Wentzville, and Winghaven, MO.

photo credit: gabbyportraits via photopin (license)

company icon