Quick answer
AC short cycling means the system turns on and off every few minutes instead of running full cycles. In Miami the common causes are an oversized system, a clogged filter or frozen coil, low refrigerant, a tripping float switch, a faulty or badly placed thermostat, and overheating from a dirty condenser coil. It wastes energy, leaves humidity behind and shortens compressor life.
Written by Sylvia Denton, HVAC Guides Editor. Updated 2026-09-22.
A healthy Miami system on a hot afternoon runs long, steady cycles, often 15 minutes or more at a time. That long run time is what pulls moisture out of the air. When a system short cycles, the compressor starts and stops constantly, the coil never gets cold long enough to dry the air, and the house ends up cool but sticky.
Every start is also the hardest moment in a compressor's life. A system that starts 10 times an hour instead of 3 is wearing its most expensive part out several times faster, and it uses more electricity doing it.
We diagnose short cycling by watching the system through several cycles and measuring what happens at the moment it shuts off: pressures, temperatures, the float switch, the thermostat signal and the compressor's safety controls.
