Air conditioner parts can get a humming, warm-blowing AC back to cold air on the same day. When the outdoor fan will not spin, the compressor clicks but never starts, or the unit trips off on hot afternoons, a failed capacitor is the most common cause, and it is one of the easiest repairs a homeowner can make with power safely shut off. BlueStars Parts stocks air conditioner replacement parts matched by microfarad (uF) rating, voltage and size.
Which Air Conditioner Parts Fix Your Problem?
Start with what the system is doing:
- Outdoor unit hums but fan does not spin: a weak or bulging dual run capacitor is the usual cause.
- Compressor clicks and will not start: a failed run capacitor or a hard start capacitor that has lost its rating.
- AC runs but blows warm air: low refrigerant, a dirty coil or a failing compressor capacitor reduces cooling.
- Unit shuts off on hot days: a capacitor drifting out of tolerance overheats the motor.
- Cold drafts around a window unit in winter: an indoor AC cover seals the gaps.
For a full checklist, read our guide on ac running but not cooling.
Popular Air Conditioner Replacement Parts
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Air Conditioner Parts by Brand and Rating
For capacitors, brand matters less than the numbers printed on the label. Match the uF rating exactly, use the same or a higher voltage (370V can be replaced with 440V), and check the can is round or oval to fit the bracket. For window and portable units, find the model tag on the side panel and shop lg parts, ge parts or frigidaire parts. Keep a simple ac parts list with your model number, capacitor rating and filter size to speed up the next repair.
Air Conditioner Repair Guides
Diagnose the problem before buying with these guides:
Air Conditioner Parts FAQ
How do I know if my AC capacitor is bad?
A bad capacitor often shows a bulging top, leaking oil or a reading below its rated uF on a multimeter. The fan or compressor hums but does not start. Always shut off power and discharge the capacitor before testing.
Which air conditioner compressor parts can a homeowner replace?
Homeowners can usually replace the run or dual capacitor, a hard start kit and the contactor. Compressor replacement and refrigerant work need a licensed technician because they involve the sealed system.
Can I use a capacitor with a different uF rating?
No. The uF rating must match the original, usually within plus or minus 5 or 6 percent. A wrong rating makes the motor run hot, draw extra current and fail early. Only the voltage can go up, for example from 370V to 440V, never down.
Where can I buy ac spare parts that match my unit?
Match the numbers on the old part first: uF, voltage and shape for capacitors, or the part number for window unit parts. Then order the same rating from a parts store that lists specs clearly, so the fit is right the first time.
Why Buy Air Conditioner Parts from BlueStars Parts
- Capacitors and valves listed with full uF, voltage and size specs.
- Fast US shipping when the heat will not wait.
- Expert support and DIY guides from a team helping customers since 2016.
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