Air conditioner short cycling on and off

Short cycling is when an air conditioner turns on, runs for only a few minutes (instead of the normal 15–20 minute cycle), shuts off, and then restarts shortly after — repeating this pattern continuously. This puts enormous stress on the compressor, which is the most expensive component to replace ($1,500–$3,000). Each startup draws a surge of electricity, so short cycling can increase energy bills by 20–40%. Common causes include a dirty or clogged air filter restricting airflow, low refrigerant from a leak, an oversized AC unit for the space, a malfunctioning thermostat reading incorrect temperatures, frozen evaporator coils, or an overheating compressor with a failing motor. An HVAC technician can diagnose the root cause, check refrigerant levels, clean evaporator and condenser coils, verify thermostat calibration, and inspect electrical components. Ignoring short cycling dramatically shortens the system's lifespan — a well-maintained AC lasts 15–20 years, but chronic short cycling can cut that to 7–10 years.