Definition
Short cycling is when an air conditioner, heat pump or furnace starts and stops in rapid, frequent cycles instead of completing normal run times. Common causes include oversized equipment, a clogged filter, a frozen evaporator coil, incorrect refrigerant charge, an overheating furnace and a misplaced or failing thermostat. It adds wear and reduces comfort and efficiency.
Why it matters to you.
In Central Kentucky's humid summers an oversized air conditioner cools the air in minutes and shuts off before it has run long enough to pull moisture out, leaving rooms cool but clammy. A furnace or heat pump that short-cycles through winter cold snaps adds start-up wear to its igniter, compressor and blower.
Practical guidance.
Check that the filter is clean and that the thermostat is not near a supply register, sunny window or lamp. If cycling continues, have a technician check airflow, refrigerant charge and safety controls, and for a replacement ask that the system be sized with a Manual J load calculation.
About this definition
Written by the Feistritzer Heating & Air Conditioning team — family owned and operated in Danville since 1976, Kentucky HVAC license M02584. Definitions inform; a whole-system diagnosis in your home decides.