Life Expectancy of Air Conditioner Capacitor

An AC capacitor lasts an average of 12-18 years. The main factors in capacitor life expectancy are initial quality, how heavily you use your AC and whether it gets regular maintenance.

This page discusses air conditioner capacitor lifespan. Factors affecting durability are explained as well as what you can do to maximize capacitor lifespan. The purpose of the capacitor is briefly explained, though most reading this will already be familiar with the purpose of an AC capacitor. 

Signs of a bad air conditioner capacitor are described that will assist you in troubleshooting a bad AC capacitor. FAQs about capacitor life expectancy conclude the discussion.

How Long Does an AC Capacitor Last?

FactorCentral ACWindow/Portable AC
Cheap Part, Cool Climate12-15 Years10-12 Years
Cheap Part, Warm Climate10-12 Years8-10 Years
Cheap Part, Hot Climate8-10 Years6-10 Years
Good Part, Cool Climate15-18+ Years12-15 Years
Good Part, Warm Climate14-18 Years10-14 Years
Good Part, Hot Climate12-15 Years8-12 Years

Central Air Conditioner Capacitor Life Expectancy

The data from technicians that replace capacitors as a routine part of their workload shows that air conditioner capacitors last 12-15 years. In other words, that is the average age of an

When you search AC capacitor lifespan, you’ll find reliable sources giving conflicting information. This page sets it all straight.

But what you’ll find are sites suggesting one of these AC parts lasts 5-20 years. One air conditioning company claims that a capacitor will last indefinitely because it is not a “wearable” part. This apparently means that it isn’t one prone to wearing out. But that would be wrong. Capacitors do wear out over time, and factors related to your AC use will impact how long an AC capacitor lasts.

Most sites that offer a number of years give the average lifespan of an air conditioner capacitor as 10 years.

Room Air Conditioner Capacitor Longevity

Window air conditioners and portable air conditioners have capacitors too. These room air conditioner types aren’t typically used as heavily as central air conditioners. But the parts used to manufacture them are usually not as good. As a result of these factors, window AC capacitor longevity is 8-14 years. For portable ACs, the capacitors last an average of 7-12 years. Capacitor lifespan for both types depends on the factors listed next.

AC Capacitor Durability Factors

How long does an air conditioner capacitor last? They are replaced on average in 12-18 years. Their durability is determined by:

Initial Quality – Some brands are known to use better parts. It’s that simple. Some of the capacitors used are made by the manufacturer, but often they are third-party parts produced by companies like Emerson and Genteq that specialize in the electrical components of HVAC equipment.

Brands with the best AC capacitors are Trane and American Standard, Carrier and Bryant, Payne (Carrier brand) and Heil, Day & Night, Arcoaire, Tempstar and Keeprite (ICP brands also owned by Carrier).

Brands with capacitors that do not offer superior longevity are Lennox and Goodman plus many of the other brands you can buy online and/or at big box stores. These include AirQuest, OxBox (Trane’s cheap AC brand), Ameristar, AirQuest, Royalton (at Home Depot), Weatherking, Blueridge (Alpine Air) and RunTru (a decent Trane brand). Generally speaking, the quality of Maytag, Broan, Gibson and NuTone is suspect at best. Equipment from these Nortek Global brands should be avoided.

Climate – This is stating the obvious, but if your climate is very warm and/or the cooling season is long (early spring well into autumn), then your AC capacitor and every other part on it is going to wear out more quickly.

In the South, Midsouth and Southwest, AC capacitor longevity is 10-12 years if the part was quality to begin with. Cheap capacitors last 5-10.

In cooler climates where running the AC is an occasional thing, then yes, a capacitor might last 20+ years. If you’re reading this, you likely don’t live in a climate with less need for AC.

Extreme Heat – In those hot climates, cheap and old capacitors start “dropping like flies” on the hottest days of the year. As a result, smart AC technicians keep a large supply of universal capacitors on their truck to swap out the bad ones ASAP. An AC capacitor is the most commonly replaced AC part.

Maintenance – There might be nothing you can do to prevent a capacitor from going bad. However, general maintenance can’t hurt. Keep the condensing unit (outdoor unit) coil clean, and the system won’t constantly work hard to get rid of hot air gathered indoors. And therefore, it won’t overheat and damage all the electrical parts including the capacitor. Most warranties say the AC owner must have annual maintenance on the unit or the warranty is voided! Is that a surprise? Well, warranty claims are rarely denied for lack of AC maintenance, but it does happen.

Wrong Voltage – Each AC model requires a capacitor with a specific voltage range. If someone previously replaced the capacitor with one with an improper voltage rating for that unit, it won’t work correctly and might fail within a few months or years.  

Signs of a Bad AC Capacitor

How to know if my AC run capacitor is bad? Or the start capacitor? Those are common questions. The signs of a bad AC capacitor are:

Intermittent Cooling: The system runs on an air conditioning cycle for more than a few minutes before cool air starts flowing. Or the airflow turns from cool to room temperature before the thermostat setting is reached. In these scenarios, the capacitor is still working, but intermittently. In other words, it might not give its electrical surge on the first try (start capacitor) or it might stop delivering the charge needed to keep the system running (run capacitor).

New Noises: The outdoor unit is making an unusual humming or buzzing noise – a hum or buzz it recently developed. The capacitor might be starting to fail.

Warm air: The system is running but won’t cool at all. And the fan will shut off, and the cycle will “quit” without air conditioning. While this could have other causes, a failed capacitor should certainly be considered.

Burnt Smell and/or Smoke: When a capacitor is “fried,” it might have a burnt electrical smell. You might even see smoke if you’re nearby at the moment it fails.

Start vs Run Capacitor

A capacitor is a battery-like device that stores energy to deliver to the system at a later time. Here’s a brief look at an AC run capacitor vs start capacitor.

Start Capacitors: They provide a surge or boost of power to get a motor moving, whether the compressor or the fan motor in a central air conditioner or room AC. The surge is normally 4-6 times the energy needed to run the AC. While the AC is running, the capacitor stores up enough energy for the next start of the motor or compressor.

Run Capacitors: These units provide a steady flow of electrical power to keep the unit running. They are often less durable because they are active during each entire AC cycle and not just at the start.  

Dual Capacitors: Many central air conditioners, window air conditioners and portable air conditioners use a dual capacitor with both a start and run capacitor integrated into a single unit. This means that the replacement part is more expensive, but not that much more. In fact, because the part cost is low, some AC technicians recommend preemptively replacing the capacitor after the AC is 10 or so to avoid a failure in the middle of a scorching-hot day.


Is capacitor replacement a DIY job?

Yes. With basic knowledge and safety skills for working with electricity, you can replace your AC capacitor in less than an hour. The first step is to safely discharge the electrical charge stored in the capacitor, if one remains. Then, it is crucial to get a new part that is the right type (start, run or dual) and of the proper voltage rating.

How much does it cost to replace an AC capacitor?

Air conditioner capacitor replacement cost is $10 to $100 for the part, but most are under $40. If you hire an HVAC contractor to provide and install the part, total AC capacitor replacement cost is $150 to $400 based on part cost, how easy access is to the part inside the unit, time of year and whether it is emergency service.

Written by

Rene has worked 10 years in the HVAC field and now is the Senior Comfort Specialist for PICKHVAC. He holds an HVAC associate degree from Lone Star College and EPA & R-410A Certifications.

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