$100 – $400That is the typical AC capacitor replacement cost in 2026, parts and labor included, with a national average of about $175 (Fixr). This Old House gives the same $175 average with a slightly lower $80 floor. The capacitor itself is a cheap part: $8 to $45 in This Old House’s guide and $8 to $50 in Fixr’s. Most of the bill is the technician’s visit, which is why a $15 part can turn into a $200 repair.
The capacitor helps start the motors that run the fan and the compressor in your outdoor unit. When it fails, the system cannot start properly, and a failing one can blow fuses or trip breakers (Today’s Homeowner). It is one of the most common and least expensive AC repairs, so this guide covers only that part: the price of each capacitor type, what the bill is made of, the signs of failure, and why this is a job to leave to a technician. For every other failed part, from the contactor to the compressor, see our full AC repair cost guide.
AC capacitor replacement cost by guide
| Guide | Total, parts and labor | Average |
|---|---|---|
| This Old House (capacitor guide) | $80 – $400 | $175 |
| Fixr | $100 – $400 | about $175 |
| Today’s Homeowner | $100 – $400 | — |
| This Old House (AC repair guide) | $150 – $400 | — |
| PickHVAC | $100 – $250 | $175 |
| Smart Service | $80 – $400 | about $175 |
The guides agree closely on the top of the range ($400, except PickHVAC) and on the average ($175). PickHVAC is the outlier at $250 for the high end, but it is an HVAC lead-generation site whose own figures change from section to section, so treat it as the weakest of the six. Its capacitor-type prices also match This Old House’s table number for number, so the two are not independent evidence.
Cost by capacitor type: start, run and dual run
| Capacitor type | Part, This Old House | Installed, This Old House | Part, Smart Service |
|---|---|---|---|
| Run (single) | $8 – $30 | $98 – $230 | $6 – $30 |
| Start | $9 – $25 | $99 – $225 | $9 – $25 (standard); $80 – $180 (high-MFD or OEM-specific) |
| Dual run | $15 – $45 | $105 – $245 | $15 – $50; up to $90 (premium or OEM-matched) |
| Blower | $9 – $12 | $99 – $212 | $9 – $20 |
| Heat pump | $15 – $25 | $105 – $225 | $15 – $45 |
A run capacitor keeps the compressor, condenser fan and blower motor running while the AC is on. A start capacitor gives a short burst of power to get the cycle going. A dual-run capacitor combines two in one canister, one for the compressor and one for the fan motor, which is why it costs the most and has to be replaced as a whole if either half fails (This Old House). Ask the technician which type your unit has before you compare quotes.
The two guides split on OEM parts. Smart Service puts a high-capacity or manufacturer-specific start capacitor at $80 to $180, far above the $9 to $25 standard part. This Old House says unit costs are typically under $50 unless you choose a high-end branded part. If a quote is near the top of the range, ask whether the part is OEM or generic.
Estimate your AC capacitor replacement cost
Our estimate: the published ranges above multiplied out for your inputs. Not a quote. Installed prices by capacitor type from This Old House (April 2026). Service call range from This Old House's AC repair guide (March 2026); the surge protector range is from Smart Service (undated). Smart Service says the diagnostic fee is often credited toward the repair if you go ahead with it. After-hours calls cost more. State adjustment: BLS construction wages (May 2025), applied to an assumed 50% labor share. How we calculate
What the bill is made of
| Charge | This Old House | Smart Service | PickHVAC |
|---|---|---|---|
| Service call or diagnostic fee | $75 – $150 (repair guide); about $129 average (capacitor guide) | $90 – $150 | $80 – $130 in its table; $75 – $150 elsewhere on the page |
| Labor, hourly | $60 – $150 in one section; $90 – $200 in another | $60 – $150 | — |
| Time on site | sometimes within half an hour | 30 to 45 minutes | — |
| After-hours or peak-season extra | no figure given | 1.5 to 2 times the normal labor rate | $50 – $150 extra |
The guides do not agree on after-hours pricing: Smart Service gives a multiplier, PickHVAC a flat extra, and This Old House only says that service on nights, weekends or holidays costs more than a booked visit (This Old House). The labor figures are also unsettled: This Old House’s capacitor guide states two different hourly ranges on the same page. Smart Service says the diagnostic fee is often credited toward the repair if you go ahead, and PickHVAC says it is often rolled into labor, so ask before the technician starts. If the outdoor unit is hard to reach, labor can rise (This Old House).
Our estimate: the part is only about 6% to 18% of what you pay. We get this by dividing the part prices by the installed prices in This Old House’s table above for each capacitor type (for example, a $15 – $45 dual-run part against a $105 – $245 installed job). It is our own calculation from published figures, not a measured price.
Signs your AC capacitor has failed
- The AC is slow to start or will not start, or it hums but the fan blade does not turn (This Old House; PickHVAC).
- The system does not stay on long enough to cool the house, or is not blowing cold air (This Old House).
- The outdoor unit clicks on and off, or makes an unusual hum (PickHVAC; This Old House).
- Your electric bill rises for no clear reason (This Old House).
- A swollen or domed top on the capacitor; a healthy one is flat-topped (Smart Service).
- A burning smell or smoke from the outdoor unit (This Old House). Smart Service advises shutting off the breaker if you see burning or smoke, then calling a technician.
Most capacitors last 10 to 20 years, though heat and frequent use can shorten that (This Old House). These signs can also point to other failed parts, so a technician should confirm the diagnosis before you pay for a replacement.
Why you should not replace it yourself
A DIY part costs $30 to $80 in PickHVAC’s table, and it says online retailers sell the part for $10 to $30. The saving is real, but so is the risk: a capacitor stores electricity even when the unit is disconnected from power (This Old House). PickHVAC warns that a charged capacitor can give a severe shock at its terminals and must be discharged with insulated tools. Smart Service says professionals discharge it through an insulated resistor and recommends hiring a technician if you have never done it. Improper handling can also burst the capacitor or damage the equipment (PickHVAC).
This Old House adds that DIY repairs can void your warranty and may lead to code violations. For a $100 to $400 repair, the technician’s fee is the cheaper side of that trade-off.
What happens if you wait
Running the AC with a failed capacitor could cause much more damage to other parts of the system, according to This Old House. PickHVAC says it may overheat the motors. Smart Service points to a $1,800 compressor as the costlier outcome of waiting. Compare that with the $100 to $400 for the capacitor. Our AC repair cost guide shows what a compressor or fan motor repair costs, and if your unit is old and several parts are failing, see AC unit replacement cost and the full HVAC replacement cost guide before you spend more on repairs. If the failed part is a furnace blower capacitor, see furnace repair cost.
How to keep the bill down
- Book a regular appointment instead of an emergency visit when you can wait, since night, weekend and holiday service costs more (This Old House).
- Ask whether the diagnostic fee is credited to the repair.
- Ask which capacitor type your unit uses, and whether the quote is for an OEM or a generic part.
- Ask for a written quote showing part, labor and call-out fee separately, and compare at least two local quotes. Smart Service says prices for the same job can differ by up to 30%.
- Have the technician check the other outdoor parts during the same visit, so you do not pay a second call-out. Regular service can also catch a weak part early; see how often to service your HVAC.
Common questions
How long does the replacement take? A professional can sometimes finish within half an hour (This Old House); Smart Service says 30 to 45 minutes on site.
Is it worth repairing? Today’s Homeowner calls it a relatively inexpensive repair that is usually worth doing (Today’s Homeowner). The calculation changes only if the unit is old and other major parts are also failing.
Can I run the AC without a working capacitor? No. Without it, the system cannot start (Today’s Homeowner), and continuing to run a unit with a failing one could damage other parts (This Old House).
Why do some older guides show a $60 low end? An older Bob Vila article (June 29, 2022, older) gives $60 to $300 with a $170 average. The 2026 guides above start at $80 to $100 and top out at $400.
Sources
- This Old House, AC Capacitor Cost, updated April 7, 2026.
- This Old House, Air Conditioner Repair Cost, updated March 16, 2026.
- Fixr, AC Repair Cost: Understanding Common Issues and When to Replace, July 31, 2026.
- Today’s Homeowner, AC Repair Cost, updated May 22, 2025.
- PickHVAC, AC Capacitor Replacement Cost for Residential Systems, June 27, 2025.
- Smart Service, AC Capacitor Cost: How Much to Replace, undated (copyright 2026).
- Bob Vila, AC Capacitor Cost, June 29, 2022 (older).
