Why Does My Furnace Keep Turning On and Off?

START HERE

Safe checks before scheduling service

1. Check the filter first because restricted airflow can contribute to overheating.
2. Confirm supply and return registers are open.
3. Note the approximate cycle length and whether the burner shuts off before the blower.
4. Check for a visible fault code without removing panels.
5. Schedule service if the pattern continues.

If you encounter exposed wiring, smoke, a gas odor, a carbon-monoxide alarm, or another immediate safety concern, stop troubleshooting and follow the appropriate emergency guidance.