How much does it cost to replace an AC capacitor?
National cost guides like HomeGuide put an AC capacitor replacement at $150–$400, even though the part itself runs about $15–$80. Most of the bill is the trip, the testing and the labor. With us, the $79 trip charge is waived when you approve the repair, and the price is written down before work starts.
Key points
- The capacitor is a $15–$80 part; HomeGuide puts the installed job at $150–$400 nationally, mostly labor and the trip.
- An outdoor unit that hums while the fan sits still is the classic sign.
- A good tech meters the old capacitor against its label, then checks the contactor, fan motor and coil for the reason it failed.
- In Minnesota, weak capacitors tend to quit on the first hot, humid week after the unit sat all winter.
- Our $79 trip charge is waived when you approve the repair.
Replacing an AC capacitor typically costs $150–$400 installed, per national cost guides such as HomeGuide, even though the capacitor itself is only about $15–$80 of that. The rest is the trip, the testing and the labor. With us, a service call carries a $79 trip charge that's waived when you approve the repair, and you get a written, flat-rate price before any work starts. The run capacitor is one of the cheapest parts in an air conditioner and one of the most common reasons an outdoor unit stops cooling.
What does an AC capacitor do?
A capacitor stores an electrical charge and releases it to get the compressor and the condenser fan motor turning, then helps keep them running. Most central air conditioners use a single dual run capacitor that serves both. It's a round or oval metal can with three terminals marked HERM (compressor), FAN and C (common). The label lists two microfarad ratings, such as 45/5 µF, and a voltage rating, usually 370 or 440 volts.
HomeGuide's range moves with the capacitor type (a single run, a dual run, or an added start capacitor), whether the unit takes a brand-specific part or a universal one, and local labor rates. The part is rarely what makes the bill.
The replacement has to match. The microfarad rating should be the same as the original, and the voltage rating the same or higher: a 440-volt can may replace a 370-volt one, never the other way around. A universal part is fine when its ratings match. A capacitor that's close but wrong stresses the motors it's meant to protect.
On our side, the finished repair carries our written 1-year parts-and-labor warranty. Full details are on our AC repair page.
Signs it's the capacitor, and what else it could be
| What you notice | Likely cause | What to do now | Who fixes it |
|---|---|---|---|
| Outdoor unit hums, fan blades sit still | Fan side of the capacitor, or a seized fan motor | Turn cooling off at the thermostat | Technician |
| Fan spins, compressor stays quiet, indoor air is room temperature | Compressor side of the capacitor, or a compressor that won't start | Turn cooling off | Technician |
| Clicks and hums, then the breaker trips | Compressor can't start: capacitor, hard-start need or failing compressor | Reset the breaker once; if it trips again, leave it off | Technician |
| Starts on a cool morning, struggles on a hot afternoon | Weak capacitor or a hard-starting compressor | Book a check before it quits | Technician |
| Domed top or oily residue on the can | Capacitor worn out by heat and age | Replace it before hot weather | Technician |
| Outdoor unit completely silent | Breaker, disconnect, thermostat, low-voltage wire or contactor | Check the breaker, disconnect and thermostat | You first, then a technician |
Some homeowners find the fan will start if they push a blade with a stick. That's a strong hint the capacitor is gone, and it's also a good way to get hurt, so skip it.
If the outdoor unit is completely silent, the capacitor is a less likely culprit. Check the thermostat, the breaker and the disconnect first, as covered in AC not turning on. If it hums, our post on a humming condenser walks through the other causes.
What does a tech check before replacing an AC capacitor?
A capacitor is easy to replace and easy to replace for the wrong reason. The order we follow:
- Power off and discharge. Pull the disconnect, verify it's dead, then discharge the capacitor. It can hold a charge after the power is off.
- Look. A bulged top, leaking oil, burnt terminals or a loose spade connector each tell part of the story.
- Meter it. Each side is measured in microfarads and compared with the label. The can lists a tolerance, commonly plus or minus 5 or 6 percent. Outside that band, it gets replaced.
- Check the contactor. This is the switch next to the capacitor that closes when the thermostat calls for cooling. Pitted or burnt contacts, or ants packed between them, can mimic a bad capacitor.
- Measure the motors. With the new capacitor in, the tech checks amp draw on the compressor and fan motor. A capacitor that failed because a fan motor is dragging will fail again.
- Look at the coil. A condenser coil matted with cottonwood fluff, grass clippings or dryer lint runs hot and pushes everything harder.
The last two steps are what separate a repair from a part swap. Most capacitors fail from heat and age, but a few fail because something else is overworking them.
Why do AC capacitors fail in a Minnesota June?
Heat is what wears a capacitor out. Here the outdoor unit sits idle from October to May, then gets asked to run hard on the first muggy week of summer. A capacitor that was already weak last August often gets through the mild days and gives up right then.
Timing makes it worse. Cottonwood seeds blow in June, and a coil coated with them runs hotter. Summer thunderstorms bring power blips. A condenser on the south or west side of the house, in full afternoon sun, runs hotter than one in shade.
A spring tune-up is the cheapest place to catch it. We meter the capacitor against its rating as part of every AC tune-up, which starts at $129 for the AC alone or $219 for furnace and AC together. If you want it on the calendar every spring, ask us about a maintenance plan. Our spring AC checklist covers the rest of that visit, and keeping the coil clean (how to clean your condenser) helps the capacitor last.
Other parts that change the bill
When the capacitor isn't the whole problem, one of these usually is. All figures are typical national ranges from HomeGuide's AC repair and capacitor guides, not our prices.
| Repair | Typical national range |
|---|---|
| Capacitor replacement | $150–$400 |
| Contactor replacement | $200–$450 |
| Condenser fan motor | $200–$700 |
| Hard-start kit | $100–$270 |
| Compressor, out of warranty | $1,800–$2,800 |
A fan motor that ran for days on a dead capacitor can overheat and need replacing too. On an older compressor that's getting hard to start, a hard-start kit can buy some time. If the compressor itself has failed on an older system, the conversation turns to replacing the AC, and we'll price both options so you can compare. Our AC replacement cost guide shows what goes into the price of a new system.
Can you replace an AC capacitor yourself?
Replacement capacitors are sold online and the swap looks simple. The risks are real, though. A capacitor can hold a dangerous charge after the power is off, and the terminals sit close together. A part with the wrong microfarad rating, or a lower voltage rating than the original, stresses the motors it's meant to protect. And a DIY swap skips the question of why it failed.
If you do electrical work already, you know the drill: disconnect pulled, charge discharged with an insulated tool, ratings matched exactly. If any of that is new to you, it's a service call.
What to do next
If the outdoor unit is humming and not starting, turn cooling off at the thermostat so the compressor stops trying. Then call 612-429-3465. We're open 7 days, 7am–9pm, and the $79 trip charge is waived when you go ahead with the repair. The price is the same whether you book AC repair in Minneapolis, AC repair in Saint Paul or anywhere else we serve.
Questions
Can I keep running my AC with a bad capacitor?
No. Turn the cooling off at the thermostat. With a failed capacitor the compressor or fan motor keeps trying to start, draws heavy current and heats up. Left that way for hours or days, a cheap capacitor problem can turn into a fan motor or compressor problem. The house gets warm either way, so shut it down and get it looked at.
How long does an AC capacitor last?
There's no fixed number of years. Heat and age wear capacitors out, so a unit in full afternoon sun or with a clogged coil goes through them faster. The practical approach is to have the capacitor metered against its rating at the spring tune-up. One that reads low in May can be replaced before it strands you in July.
Is the capacitor covered by the manufacturer's warranty?
Often, if the equipment was registered and is still inside its parts warranty. Most manufacturer parts warranties cover the part and not the labor or the service call, so you would still pay for the visit and the install. Your installation paperwork or the manufacturer's website shows the terms for your model.
Why does my AC start in the morning but not in the afternoon?
That pattern often points to a weak capacitor or a compressor that's getting hard to start. On a cool morning the compressor starts easily. On a hot afternoon the pressures are higher and a weak capacitor can't get it going, so the unit hums and trips out. A capacitance reading tells a tech which one it is.
Sources
- HomeGuide cost guides (2026 editions) homeguide.com