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HVAC

Why does my AC or furnace turn on and off constantly instead of running normally?

What’s likely going on

Called "short-cycling," and it's usually a sign of something more specific than simple wear — an oversized system for the space, a dirty filter causing it to overheat and shut off as a safety measure, or a genuine mechanical fault. It also puts real extra strain on the system the longer it continues.

Is this a DIY job or worth calling someone?

Worth checking the filter first, since that's the free and safe step. Short-cycling that continues after a clean filter is a real diagnostic question worth having answered soon — the longer a system runs this way, the more wear it puts on itself.

Not sure, or ready to have someone take care of it?