What is short cycling and why is it bad for my HVAC system?

Short cycling is when your heating or cooling system turns on, runs for just a few minutes, shuts off, then starts again shortly after — instead of running a full cycle.

It's hard on the compressor (the most expensive part of an AC), wastes energy, and usually means the system is oversized for the space, has a refrigerant issue, or has a failing thermostat or control board.

A system that short-cycles will wear out significantly faster than one running normal cycles.