Furnace keeps turning on and off
The furnace starts, runs a few minutes and shuts off, over and over.
What you're probably seeing
The furnace starts, runs a few minutes and shuts off, over and over.
Likely causes
- A dirty flame sensor.
- Overheating from poor airflow.
- A thermostat in a bad spot or failing.
- An oversized furnace.
Safe checks you can do now
- Replace the filter.
- Open closed vents.
- Check the thermostat isn't near a heat source.
When to call a pro
It keeps cycling after a new filter.
General information about common causes, not a diagnosis of your home.
FAQ
Quick answers
Who fixes furnace keeps turning on and off?
A heating and cooling company. Call (844) 511-3573 to connect with an independent local heating and cooling company.
How much does it typically cost?
Furnace repair: $125–$480 (ignitor $100–$250, flame sensor $80–$250, blower motor $300–$900) (HomeGuide 2026 national ranges). Your pro sets the real number after seeing the job.
When should I call?
It keeps cycling after a new filter.
Related
More heating & cooling problems
Fix nowPlumbing
Gas smell in the house
A rotten-egg smell near the stove, furnace, water heater or meter.
$45–$150 per hour, plus a $50–$200 service call
Fix nowHeating & Cooling
No heat
The furnace or heat pump won't come on, or the house keeps getting colder.
$125–$480 (ignitor $100–$250, flame sensor $80–$250, blower motor $300–$900)
This weekHeating & Cooling
Furnace blowing cold air
Air comes from the vents but it isn't warm.
$125–$480 (ignitor $100–$250, flame sensor $80–$250, blower motor $300–$900)