Problem Center · Heating
Why Is My Furnace Short Cycling?
The furnace turns on and off every few minutes.
What could cause this?
- Overheating from restricted airflow
- Flame sensor problems
- Oversized furnace
- Thermostat location or settings
- Venting or pressure switch issues
What you can safely check
- Replace a dirty filter
- Make sure vents and returns are open
- Check whether the thermostat is near a heat source or drafty spot
Don't open electrical panels or equipment cabinets, handle refrigerant, work on gas or combustion components, or bypass safety controls.
When it requires a professional
Short cycling wastes energy and wears the furnace. If it continues with a clean filter, request service.
How Air Mechanical diagnoses it
We look at temperature rise, airflow, flame sensing, limit operation, sizing and thermostat setup.
Every diagnosis starts with the system as it actually exists — equipment, controls, wiring and installation. The equipment has a brand. The problem has a solution.