What it is
A capacitor is the jolt that gets your compressor and outdoor fan moving. They fail constantly, especially after a few hot summers, and they are the single most common thing a technician replaces.
What you would notice
- The outdoor unit hums but the fan does not spin
- You can start the fan spinning with a stick and then it keeps going (classic sign — and do not do this)
- The unit clicks on and then shuts off within a minute
- Air is blowing indoors but it is not cold
Can you do this yourself?
Partly yours
The part is trivial. The risk is not. A capacitor holds 400–600 volts after the power is off, and discharging one incorrectly is how people get hurt. If you do not already know how to discharge a capacitor, this is a job you pay for — but you pay for it knowing the part inside was $20.
What to say when you call
Red flags
- A quote over $400 for a capacitor alone, outside a genuine emergency call-out
- Being told you need a whole new condenser because of a failed capacitor
- Refusal to show you the old part
The call-out alone runs $100–$250 before any work, plus $40–80/hr on top, evenings and weekends. A whole new system is $3,800–$7,500 — compare every quote to that.
Where these numbers come from
- This Old House, AC capacitor cost guide — part $8–45, installed $80–400, average ~$175
- Angi, HVAC repair cost guide
Did it turn out to be this?
Nobody has ever published how often an AC call turns out to be something cheap — the best figure available anywhere is one company's marketing page. So we are building it. No account, no email, and your ZIP is cut to three digits before it is sent.
← Every AC repair, with both numbers
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