AC won’t start? It might be the capacitor
One of the most common — and cheapest — reasons an air conditioner quits in the heat is a failing capacitor. Here’s how we test for it, and why catching a weak one early protects the expensive parts.
What a capacitor does
The capacitor is a small cylinder that gives your AC’s motors the jolt they need to start and the steady push to keep running. When it weakens, the system struggles to start, runs hot, or quits altogether — usually right when you need cooling most.
The signs of a bad capacitor
Classic symptoms: the outdoor unit hums but won’t start, the fan needs a nudge to spin, the AC trips the breaker, or it blows warm air because the compressor can’t get going. A swollen or leaking capacitor is a dead giveaway.
How we test it — no guessing
We measure the capacitor with a meter and compare it to its rating in MFD (microfarads). On a recent call, a capacitor rated at 33 MFD tested at just 3.0 — far out of spec. That’s a part on its last legs, even if the AC was still limping along.
Why a weak one is worth catching early
A failing capacitor makes your compressor and fan motor work harder — and those are the costly parts. Replacing a cheap capacitor at the first sign of weakness can save you from a compressor failure that costs many times more.
Don’t guess — test it
If your AC won’t start or keeps tripping, don’t throw parts at it. We’ll test the capacitor and the rest of the electrical, find the real cause, and quote the fix upfront. We offer same-day and after-hours AC repair across the Salt Lake Valley — book an AC repair or call 801-960-5925.
Get a straight answer
Tell us what’s going on and we’ll give you honest options and upfront pricing — no pressure, no runaround.
See the difference a careful job makes
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