Your air conditioner’s capacitor is a small cylinder located in the outdoor unit that provides the electrical kick your AC needs to create cold air. Capacitors are fairly sturdy, but they do burn out over time. Luckily, this is an inexpensive air conditioner part to replace. The capacitor itself costs an average of $8–$45, but the overall price to have it replaced ranges from $80–$400.

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What Is The Average AC Capacitor Cost?

Fortunately, capacitor replacement is a relatively inexpensive HVAC repair job. If you purchase a new capacitor and try to replace it yourself, you may be able to do it for as low as $80, though this isn’t recommended. If you hire a professional AC service and request a high-end capacitor, you could pay as much as $400. The average cost of capacitor replacement is around $175.

Low-End	Average	High-End
$80	$175	$400

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What Is an AC Capacitor?

Air conditioning systems don’t run constantly—that would be a massive waste of electricity. Instead, they turn on when the thermostat shows the indoor temperature has risen to a certain level. To turn it back on, they need a jumpstart of electricity, and the HVAC capacitor is what provides that jump. The capacitor stores energy like a battery and uses it to start the system and keep it running steadily.

An AC unit may have one capacitor for starting and running or separate capacitors for these functions. When a capacitor fails, it’s essentially a dead battery that needs replacing. An AC system can’t run with a bad capacitor, so your air conditioning may work poorly or stop working altogether. Capacitors have a lifespan of about 10–20 years and are so inexpensive that it’s usually better to replace than repair.

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How Much Does Each Type of Capacitor Cost?

Unlike an evaporator coil or the cost of an entire HVAC unit, the unit cost for the various types of capacitors is actually quite low—typically under $50 unless you seek out a high-end branded unit. Labor to replace the capacitor makes up most of the total cost.

• Run Capacitor Cost: Once the start capacitor has started the cooling cycle, the run capacitor sustains it. The run capacitor keeps the AC compressor, the condenser fan motor, and the blower motor operational whenever the air conditioner is on. These devices cost about $8–$30.
• Blower Capacitor Cost: It’s not just air conditioners that have capacitors. Furnace blower motors also need this part in order to circulate heat throughout a home’s air ducts. Your home’s HVAC system may use the same blower motor for both heat and cooling, meaning that this capacitor has to work year-round. Fortunately, the part is inexpensive at $9–$12.
• Start Capacitor Cost: As the name implies, an air conditioning unit needs a start capacitor to start up. Similar to a car starter, this device provides a burst of energy to begin a cooling cycle (one that might be too much for a home’s electrical system to handle on its own) and then turns off once the unit is running. Start capacitors typically cost $9–$25.
• Dual Run Capacitor Cost: Instead of having separate start and run capacitors, some systems have a single capacitor that takes care of both. These devices are larger and cost a bit more—usually $15–$45—but they can supply power to much larger HVAC systems. Unfortunately, if one part of this capacitor fails, you must replace the whole thing.
• Heat Pump Capacitor Cost: Heat pump systems can also be used to bring cool air into a house and in some ways, operate very similarly to traditional air conditioners. A heat pump capacitor usually serves the same functions as a dual-run capacitor and thus costs about $15–$25.

AC Capacitor Type	Average Unit Cost	Average Total Cost
Run capacitor	$8–$30	$98–$230
Blower capacitor	$9–$12	$99–$212
Start capacitor	$9–$25	$99–$225
Dual run capacitor	$15–$45	$105–$245
Heat pump capacitor	$15–$25	$105–$225

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What Are Factors That Impact AC Capacitor Costs?

Aside from the type, here are some things that influence AC capacitor prices.

HVAC Unit Size

Larger HVAC units will require more powerful capacitors. Air conditioner capacitor size is measured in microfarads as well as volts, and an underpowered capacitor will fail to start the cooling cycle. Price doesn’t scale directly with size, but if you have a very large, powerful HVAC system, a capacitor with a high enough voltage rating will probably cost more.

HVAC Unit Type

A capacitor for a window unit or a mini-split system may be less expensive than one for a central air conditioner.

Labor Costs

Variation in AC capacitor replacement costs can be mostly attributed to labor. HVAC contractors may charge anywhere from $90–$200 depending on the type of system and how accessible the capacitor is. You may pay more if the technician has difficulty accessing the part. The HVAC company may also charge a flat service call fee no matter how quick the job is to complete.

Location and Climate

If you live in a hot climate that needs frequent air conditioning, you’re working your AC system heavily, which may lead to your capacitor burning out more quickly. The same is true for your furnace blower motor capacitor if you need heavy cooling in the summer and heating in the winter. Additionally, AC repair services may cost a bit more in the dead of summer when contractors are more in demand and can charge more for their time.

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Should You DIY vs Professional AC Capacitor Replacement?

Although some homeowners may be tempted to save on labor costs, replacing your air conditioner’s capacitor isn’t a do-it-yourself (DIY) job. In fact, most HVAC repairs are not DIY jobs. Jim Fuson, owner of 21st Century Home Inspections, says DIY repairs often lead to code violations, voiding the unit’s warranty or seriously threatening a homeowner’s well-being. Learn more about your options below.

Professional AC Capacitor Replacement

This isn’t even a job most contractors or handypeople can do. Professional HVAC technicians must be licensed in order to install or repair air conditioners, and it takes a great deal of education and training to receive a license. Here are the general steps an AC service professional will take to replace a capacitor.

1. Open the AC unit and locate the old capacitor.
2. Carefully remove and discharge the capacitor using a grounded screwdriver.
3. Use the same screwdriver to drain the residual charge from the wires.
4. Test the capacitor with a digital multimeter.
5. Potentially remove the bleeder resistor to test the capacitor with an analog meter.
6. If the capacitor is below the rated energy value, replace it with a new one.

A pro can complete the job quickly and efficiently, sometimes within half an hour. HVAC companies also typically offer a warranty on their work should further AC problems develop.

DIY AC Capacitor Replacement

You risk serious injury by trying to replace a capacitor yourself. That’s because capacitors are high-voltage devices that store electricity even when disconnected from power. You should also be careful when dealing with refrigerant lines, as the material is toxic, and a leak should be diagnosed, repaired, and recharged by a licensed pro. You can save yourself a lot of time and effort by hiring a professional from the start and using your time for other home improvement jobs.

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How Can You Save Money on AC Capacitor Replacement?

Even though you should hire a pro for this job, you can still save some money with the following tips.

• Purchase your own replacement capacitor and hire an HVAC technician to install it. However, make sure you purchase the correct size, voltage, and type.
• Recognize the signs of a failing capacitor early and shut off your AC unit immediately. Continuing to run it could cause much more substantial damage to other system parts.
• If possible, have your AC serviced in the off-season when contractors are less in demand.
• If you need more than one HVAC service, ask the company about package deals or discounts.
• Keep up with regular HVAC maintenance and cleaning to ensure your system is working as efficiently as possible.

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Our Conclusion

Although the capacitors themselves are relatively cheap, you’ll need to pay an HVAC professional to replace one or more of your air conditioner’s capacitors. Don’t take chances with your safety and your family’s comfort—have a licensed AC technician diagnose and repair this problem. If you don’t have a trusted HVAC repair company, we recommend getting quotes from at least three contractors before making your choice. 

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FAQ About Replacing an AC Capacitor

How do I know if my AC capacitor is blown?

Here are the telltale signs of a broken or failing capacitor.

1. Your AC takes a while to turn on.
2. Your AC doesn’t turn on at all.
3. Your AC doesn’t stay on long enough to cool your home.
4. Your energy bills increase unexpectedly.
5. You hear unusual humming noises from the outdoor condenser unit.
6. You see smoke or smell a burning odor coming from the outdoor unit.
7. Your AC isn’t blowing cold air

How long do AC capacitors last?

Most capacitors will last up to 20 years, though some may begin to fail after 10 years. If your air conditioning system is older, it’s a good idea to have an HVAC repair professional check the capacitor if the system isn’t working properly.

What causes an AC capacitor to fail?

Your air conditioner’s capacitor works by storing energy and then releasing it when the thermostat tells the system to turn on. Over time and with heavy use, the capacitor will burn out. Power surges like lightning strikes or power grid fluctuations may also cause an old capacitor to fail.

How many capacitors are in an AC unit?

Typically, your air conditioner will have either one dual run capacitor or both a start capacitor and run capacitor. Some furnace systems may also have a capacitor to power the blower fan motor.

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