Air conditioner unit

If one component of your air conditioning (AC) unit fails, others can quickly follow. A common issue is the AC capacitor, a vital energy storage device located in every air conditioner. Luckily, these components are fairly inexpensive to replace. Use our guide to identify if your capacitor is the problem and learn how much you can expect to pay to replace it.



What Is an AC Capacitor?

Air conditioners use a capacitor device that stores energy and delivers it back to the unit when a stronger jolt of energy is required to jumpstart the cooling cycle. An AC capacitor also provides additional energy throughout the cooling cycle.

There are two main kinds of AC capacitors: start and run capacitors. Start capacitors provide the energy required to start the cooling cycle, while run capacitors keep the AC system going until the cooling cycle is over. Many AC units have a single capacitor that performs both tasks. These are known as dual capacitors. Most units also have a blower capacitor that keeps the fan’s blower motor in the air handler operating.



How Much Does AC Capacitor Replacement Cost?

Air conditioning capacitors come in various sizes and models. Some capacitors are specific to particular AC units or heat pumps. Because of these factors, replacement cost varies, but most capacitors are priced between $9 and $50. The biggest portion of your total comes from the HVAC contractor’s labor cost, which is typically $170 to $400. The average AC capacitor costs around $180.

  • Low-end replacement cost: $120
  • Average replacement cost: $180
  • High-end replacement cost: $400



Other AC Capacitor Costs Factors

Though a fairly straightforward repair project, other factors influence each homeowner’s AC capacitor replacement cost. Below are the various cost factors associated with AC capacitor replacement. 


A local HVAC contractor will likely charge $60 to $200 to replace your capacitor. However, many HVAC technicians charge a flat replacement rate of $120 to $250.


The average cost of living is higher in densely populated areas such as cities; thus HVAC contractors charge more for their services. Labor costs tend to be lower in more rural areas.


AC capacitor replacement isn’t a simple do-it-yourself (DIY) job, but you can try to save money on labor by replacing the capacitor yourself. You should not attempt this repair unless you’ve done plenty of research, own the proper tools and safety gear, and understand electrical best practices and an AC system’s inner workings.

If you’re interested in a DIY replacement, you’ll need the following tools and gear: 

  • Insulated screwdriver: $15
  • Nut driver: $5
  • Safety glasses: $10
  • Safety gloves: $20

Type of AC Unit

Air conditioners and heat pumps require capacitors to run. Though both systems are similar, heat pumps require specific capacitors that are different from typical AC capacitors. Heat pump capacitors are slightly more expensive than air conditioner capacitors, so this can significantly influence the overall cost of your capacitor service call.

Type of Capacitor

One of the most significant cost factors for AC capacitor replacement is the type of capacitor itself. Run, start, and blower capacitors are the least expensive. Dual and heat pump capacitors could cost an extra $20.

Here are the average AC capacitor prices by type:

  • Blower capacitor: $9–$15
  • Dual capacitor: $15–$45
  • Heat pump capacitor: $15–$45
  • Run capacitor: $8–$30
  • Start capacitor: $9–$25



When To Replace Your AC Capacitor

AC capacitors have a reasonably long life span of around 20 years but eventually give out. Below are common signs you need to replace your AC capacitor. 

Burning Smell 

You might have a failing motor component if you notice a burning smell. This indicates that the coated wires within the unit are being overcome with heat. An AC capacitor holds a lot of electrical energy, even when failing. A fire hazard develops if the capacitor can’t deliver that energy where it needs to go. If a burning smell from your AC unit is getting stronger or you notice smoke around the unit, you should immediately call 911 to prevent a severe disaster.

Clicking or Humming Noise

A dying AC capacitor might make a clicking or humming noise while operating. However, other AC parts make similar noises when they break down. An HVAC professional will need to diagnose if it’s a capacitor issue or something else.

Difficulty Starting

Your AC unit should turn on effortlessly. It’s normal to hear or feel an AC starting, depending on its placement in the house. However, it shouldn’t sound like it’s straining or struggling. If it seems like your unit is attempting to kick on but doesn’t start the cooling cycle, its capacitor could be failing. However, there could be other parts to blame. You should work with an HVAC expert to figure out the problem.

Increased Energy Bills

Your energy bills will increase during the warmer months, but a large and unexpected increase might signal an issue with your air conditioning system. A high electricity bill could mean a capacitor is struggling to hold its charge and is constantly producing more energy to store. We recommend contacting your electricity company to ask for a daily breakdown of your home’s kilowatt usage. Analyze these reports to look for trends between the days you run your AC and those you don’t.

Warm Air

One of the most prominent signs your AC capacitor is failing is when the air conditioning unit isn’t blowing cool air and only blows warm air. In hotter climates, an AC unit with a failing capacitor can’t keep up, but if the blower fan is still functional, warm air blows throughout the home instead of cold air. If this happens, you should call an HVAC professional immediately. Not having air conditioning can be uncomfortable, and extreme heat can make it dangerous.



Contact a Professional

You can attempt a DIY AC repair, but it isn’t advisable. HVAC systems are complex and expensive. Hiring a professional HVAC company ensures repairs are completed safely and properly. They can also fix your AC capacitor promptly if it unexpectedly breaks.

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Frequently Asked Questions About AC Capacitor Replacement Cost



When to Consider a Broader Home Inspection

When purchasing or selling a home, it is critical to complete a thorough inspection to understand the condition of the property. A standard home inspection includes an assessment of a home’s systems and physical structure. After the process, the inspector will provide a report detailing their findings and recommendations.

If you are thinking about buying a home or putting your home on the market, we strongly recommend finding an ASHI home inspector in your area.