A capacitor stores electrical energy and releases it in a burst to help motors start (start capacitor) and run efficiently (run capacitor). HVAC systems have capacitors on the compressor, condenser fan, and blower motor.
Capacitors are the most common HVAC failure point — they take a beating from Colorado’s temperature swings and gradually lose capacitance over time. A failed capacitor produces dramatic symptoms (system won’t start, motor hums but won’t spin, compressor trips breaker) from a $35 part.
Signs of a failing capacitor
- Outdoor unit hums but fan won’t spin
- AC compressor clicks but won’t start
- Higher electric bills as motors work harder
- Capacitor visibly bulged or leaking oil
- Burning smell from the unit
Capacitor replacement is one of the fastest repairs in HVAC — typically 20-30 minutes including testing. Most repairs run $185-$295 including the trip and labor. We carry common capacitor sizes on every truck.
Capacitors Store Lethal Voltage
Even with power off, capacitors can hold 400+ volts for hours. Don’t DIY a capacitor swap unless you know how to safely discharge one. Failed capacitor symptoms are a $185 service call worth paying for.
Related: Contactor, Compressor, Blower Motor.
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Right Way Mechanical is a family-owned HVAC contractor serving Wheat Ridge, Arvada, west Denver, and the Colorado foothills.