Derek ColeGM, Simmons One Hour Heating & Air · AI HVAC Answers

HVAC Capacitors

28 Jan 2026 · 0 min

Episode

28 Jan 2026 · 0 min

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Derek Cole discusses HVAC capacitor failure with a co-host. Capacitors degrade over time and can swell, burst, or lose capacitance from lightning strikes or power surges. Replace them when capacitance drops to about 5% of the designed value.

Questions this episode answers

May 29, 2018

Derek Cole

About 5% of the capacitor's designed value (replace when it falls to roughly 5%).

After you get years and years of wear and tear and them running with a motor, you will typically see them start, lose their value and fail. They can fail in multiple ways. They can swell and bust or they can just lose their power and not start or let the system run like it needs to. They also can fail if that motor is running during a lightning strike or a power surge. That incoming voltage can throw these capacitors off and need to be replaced.
Is there a good way to prevent these from going out or can you?
Well, there's really not a way that you can actually prevent them, but you can help catch that problem before it turns into an issue. To where you don't have air conditioning Routine maintenance. If you have regular routine maintenance, your system checked right like it needs to be, you can catch these when they start to lose their value. You do not want to see this value go below about 5% of what it's designed to do before you start changing them out.