What is the lifespan of an AC capacitor?

Author: Morton Hyatt  |  Last update: Thursday, July 9, 2026

Like with everything in life, a capacitor has a lifespan as well. In general, you can expect most AC capacitors to last about 20 years. This is a fairly long lifespan, which is why most heating and AC repair companies will take a look at the capacitor last. They expect the capacitor to last for quite some time.

How often should you replace AC capacitor?

For most ACs, this is about 15 to 20 years. However, even though your air conditioner might be rated to last this long, this doesn't mean that all of its components will. In most households, AC capacitors need to be replaced approximately twice throughout an air conditioner's lifespan.

How do I know when my AC capacitor is bad?

A sure sign of a bad AC capacitor is a humming sound from within the access panel. Any humming noises indicate a problem with the air conditioning system or the components of the AC unit. Try turning the power on and off again to see if it was a one-time issue with the motor or a recurring problem.

Is it worth replacing the capacitor on an AC unit?

All AC and heat pump capacitors fail eventually.

Capacitors are one of the most common parts that need to be replaced on residential air conditioning systems. They typically provide several years of service, but you'll need to replace them at least once if you keep the same air conditioner for more than ten years.

What is the average cost to replace a AC capacitor?

For AC capacitor replacement, anticipate spending between $150 and $400, depending on the capacitor's type and accessibility. A bad AC capacitor is a fairly minor repair, and most HVAC technicians will recommend a repair rather than replacing the unit when the capacitor is the problem.

How long does AC capacitor last?

Is it OK to run AC with bad capacitor?

Can My Air Conditioner Run on a Bad Capacitor? Over time, the capacitor can become corroded or damaged, which can prevent it from working properly. While your HVAC system may still run, it's not wise to continue using the cooling cycle until an AC capacitor replacement is installed.

Can I replace AC capacitor myself?

Since AC capacitors are high-voltage components that might cause significant injury to you even if the power is out, it is strongly recommended against changing them yourself. Follow any instructions provided with your new unit purchase if you're thinking about replacing your own AC capacitor filter.

Why do AC capacitors fail so often?

Overheating. If your air conditioner is constantly running or is too old, this can cause the capacitor to overheat and fail. To prevent this, it's helpful to give your system a break every now and then by turning it off for a few hours. This will help prolong your air conditioner's life and its parts.

What damages AC capacitor?

Minor power surges or other fluctuations in power also overload the capacitor and may cause it to fail. Your AC capacitor may also fail if the fan motor burns out or is somehow impeded from spinning freely. The capacitor continues to send power to try and operate the fan but eventually overloads and burns out.

What are the 2 typical signs that a capacitor is bad or has failed?

Bad AC Capacitor Symptoms Checklist
  • Smoke or a burning smell from exterior air conditioning components.
  • A humming noise from your air conditioner.
  • Your air conditioner takes some time to start a cooling cycle once you turn it on.
  • The air conditioning system shuts off at random.

What is the most common part to fail on an AC unit?

#1 Most Common Air Conditioning Repair – Bad Capacitor

The fan of course makes a whirring noise, the compressor is like a deep buzz like a refrigerator running. Holding your hand above the fan should feel warmer than the outside air.

What is the life expectancy of an AC capacitor?

On average, AC capacitors last 10 years, but their life span can range anywhere from five years to 20.

Can I run my AC without a capacitor?

These components are essential for powering your air conditioner, enabling it to operate efficiently. Without capacitors, your system simply couldn't function. There are two main types of capacitors within your AC unit: start and run capacitors.

How do I know if I need a new AC capacitor?

After having your helper shut the system off, you will want to stand next to the blower or the HVAC unit to hear if the unit makes any noises when it tries to start. If you don't hear anything and the unit doesn't try to start, the problem is due to something other than the capacitor.

Does AC capacitor brand matter?

Branded and generic AC capacitors play the same role in the function of an air conditioner. There's no difference between them if you choose the right capacitor size for your unit. However, some AC manufacturers may insist on sticking with their branded capacitors to prevent voiding the warranty.

How much does it cost to replace an AC capacitor?

The average cost to replace an AC capacitor is $180. Prices usually range from $200 to $400 depending on the type of capacitor and system you have.

How long does it take to replace a capacitor on an air conditioner?

In most cases, replacing an AC capacitor will take between 1 and 2 hours. However, some more complex cases could take up to 4 hours.

What is the difference between a run capacitor and a start capacitor?

The start capacitor creates a current to voltage lag in the separate start windings of the motor. The current builds up slowly, and the armature has an opportunity to begin rotating with the field of current. A run capacitor uses the charge in the dielectric to boost the current which provides power to the motor.

Can I test a capacitor without removing it?

To perform a check on a capacitor while it is still installed in a circuit, an ESR meter will be necessary. If the capacitor is removed from the circuit then a multimeter set as an ohm meter can be used, but only to perform an all-or-nothing test. This test will only show if the capacitor is completely dead, or not.

Can you test an AC capacitor while running?

Yes with a multimeter and using the microfarad function to check a capacitor maybe nice.

Is it okay to run AC with a bad capacitor?

The simple answer is “No.” There are two types of capacitors–the start capacitor that signals the AC motors to start up, and the run capacitor that keeps those motors running through each cooling cycle.

How many capacitors are in an AC unit?

Depending on how your HVAC system is built, there may be two single capacitors or one dual capacitor in your outdoor unit. Systems requiring two single capacitors need a start capacitor and run capacitor to function properly.

What are the signs of a bad AC capacitor?

Most common first signs of a bad AC capacitor:
  • Vents Not Blowing Cold Air. ...
  • Higher Than Usual Energy Bills. ...
  • Unusual Compressor Humming Noises. ...
  • Older HVAC System. ...
  • Independent Shutdown. ...
  • Sluggish Turn On and Operation. ...
  • AC is Inoperable.

Previous article
Can an air purifier cause post nasal drip?
Next article
How do realtors count bathrooms?