How Long Do Air Conditioner Capacitors Last?

Two crucial pieces of powering your cooling system are the start and run capacitor. Without a functioning capacitor, your AC unit may suddenly stop working or fail to turn on and leave you in need of quick repairs. How long do air conditioner capacitors last before you need to replace them?

The experts at Fast Air Repair, Reddick's reliable heating and air company, reveal everything you need to know in this helpful guide. Discover how these devices work, their average lifespan, and how you can tell it's time to replace them. 

What Are Air Conditioner Capacitors?

Before we answer "How long do AC capacitors operate for?" let's first dive into what these devices are and how they function. The capacitor is a small but significant piece of any air conditioning system. It works similarly to a rechargeable battery that stores and supplies energy to your cooling system. 

You may have more than one capacitor within your unit, as most air conditioners feature a start capacitor and run capacitor. Start capacitors help your unit power on by producing the electricity needed to start the air conditioner's motor and fans. Normally this device only functions while the unit is starting to power up and will disengage once it's running. 

Run capacitors are responsible for keeping the unit running until there's enough cool air in your home to match the thermostat's temperature. If your run capacitor only powers one motor, it's known as a single-stage run capacitor. If it helps run more parts and your air conditioner has a condensing unit, this is known as a dual-stage run capacitor. 

How Long Do Air Conditioner Capacitors Last? 

The average AC unit may have a capacitor lasting up to 20 years. However, several factors can alter the life expectancy considerably. Below is a breakdown of common issues that impact the lifespan of your air conditioner capacitor. 

Temperature and Overall Use

Homeowners in warmer climates often find that their capacitors start to fail quickly. These devices are sensitive to heat and may not be able to hold a charge in hot, humid areas. Without any energy in storage, the capacitor can't kickstart your cooling system and keep it running. 

Those in hotter climates will need to use their air conditioning more often, which can also cause premature capacitor failure. Installing your air conditioner in a cooler, shaded spot can prevent overheating. Adjust your thermostat so the air conditioner doesn't run as frequently. This can also extend the lifespan of your capacitor. 

Incorrect Voltage

If you need a new capacitor after a few years, always count on licensed HVAC technicians for the job instead of attempting to replace it yourself. Amateurs often end up placing a new capacitor that doesn't match the voltage rating of the old device. As a result, the capacitor will fail more quickly. 

Age

Air conditioning capacitors generally last a while, especially if you keep up with regular maintenance. Any issues you face with the unit could be due to the capacitor's age and indicate that replacement is necessary. 

Signs Your Capacitor Is Starting to Fail

Knowing the answer to "How long do air conditioner capacitors last?" can give you a sense of when you'll need to replace this component. How can you tell if the capacitor is failing or if the issue lies in another part of the unit? Look out for the following signs and contact an HVAC technician for assistance. 

The Unit Doesn't Blow Cool Air

One of the most obvious ways to tell that something's wrong with your air conditioner is if it doesn't produce any cool air. Any number of mechanical problems can be responsible for this, including:

• Clogged air filters
• Faulty thermostat
• Failed fan or motor blower

You can troubleshoot this by changing your air filter and adjusting the thermostat settings. If the unit still won't blow any cold air through your house, contact a professional. You may need repairs to the motor blower, or the capacitor could be on the brink of failure. 

The Unit Is Slow to Turn On or Doesn’t Turn On at All

The answer to "How long do air conditioner capacitors last?" varies for start and run capacitors. Since start capacitors disengage once the unit is running, they will usually last longer than their counterparts. However, you'll know there's a problem with your start capacitor if the air conditioner has delays powering on or won't start at all. 

Your Air Conditioner Makes Strange Noises

It's common for your air conditioning system to make certain sounds while it's running. Get used to these sounds and take note of anything that is out of the ordinary. For example, if you hear a humming noise that doesn't usually occur, it could be the capacitor struggling to keep up its energy supply. 

The Air Conditioner Stops Unexpectedly

Just as the start capacitor may be the source of the problem turning on your unit, the run capacitor may be failing if the system suddenly quits working. Having your system suddenly shut down is not just an inconvenience; it's a good sign that your run capacitor doesn't have the energy to power the unit anymore. Reach out to a professional to get a new capacitor and restore your home's cooling. 

You Notice Smoke or Burning Odors from the Unit

Air conditioning capacitors hold a lot of energy and electrical charges. If they were to overheat, the device could start smoking or you might notice a burning smell coming from the unit. Turn off the air conditioner right away and contact a professional technician for repairs. 

Continuing to run the system with damage to the capacitor can cause further mechanical issues. 

Your Energy Bills Are Higher Than Normal

Air conditioning capacitors help supply energy to your cooling system. If they aren't working properly, the system has to work that much harder, which will reflect in your monthly energy bills. Be mindful of any steady changes in your energy costs, as this could point to issues with your capacitors. 

How to Check the Air Conditioner Capacitor

How long do air conditioner capacitors last, and how can you check the condition of yours? Reach out to a trusted HVAC technician at the first sign of a faulty capacitor. They will check the device and how much energy it's able to supply your unit. 

Experts use a tool called a multimeter, which measures the voltage your device receives when charged with a known current. If the inspection determines that your capacitor is starting to fail, a technician can replace it. Depending on the age and condition of your AC unit, it might be worthwhile replacing the entire system rather than just one piece. 

Say both your start and run capacitors are worn down, and your air conditioner is 12 years old. Experts suggest replacing the unit if it has frequent problems and is over ten years old. In this case, you can upgrade to a more efficient unit and enjoy brand-new capacitors that have a long lifespan. 

Contact Fast Air Repair for Professional Air Conditioning Repairs



How long do air conditioner capacitors last? How do I reset an air conditioner breaker that keeps tripping? The experts at Fast Air Repair have the answers to these questions and more. 

Contact our team whenever you have problems with your heating or cooling system. We'll inspect all components and perform repairs or replace the system if necessary. Call (352) 290-7968 to schedule an appointment with our friendly technicians.