My hot air gas furnace comes on and cycles through. But sometimes the gas lights the burners and then they go out after 10 seconds and the blower is just blowing room temp air. The furnace is only 1 yr old. I checked the flame sensor and its clean. What else could be the issue...

  • Does the furnace display any error codes? When's the last time you changed the filter? – Tester101 Dec 20 '16 at 12:37
  • What make/model is the furnace? – ThreePhaseEel Dec 20 '16 at 15:27
  • Is the "flame sensor " (thermocouple) in the flame when it is burning? Occasionally a piece of ? Gets on the jet and blocks part of the flame. Without direct flame on the thermocouple the system shuts down thinking the flame went out. Usually thermocouples last for years but it could have failed. – Ed Beal Dec 21 '16 at 0:30

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.