During the heating time when the furnace is running to reach the temperature ask for, the burners will run for 3.5 to 4 mins.than shut off for 1 min. Then turn on again.it will do this until temp. is meet. The blower will run for another 3 to 4 mins. After furnace shuts off.

Is this sequence normal?

  • What is the make and model of the equipment? Does the furnace display any error codes? When is the last time you changed the air filter? It sounds to me like the furnace is overheating, and the burners are being turned off/on by the high limit switch. This commonly happens when the air flow through the furnace is restricted. The restriction could be due to a dirty filter, closed/block registers, closed/blocked returns, etc. – Tester101 Jan 26 '15 at 10:56

Probably. You'd have to inquire of the furnace maker if it is or is not. Speculating, since we have no information about what make or model furnace you have, it probably runs the burner until the heat exchanger is too hot, shuts off the burner until it's too cold, and starts it again. Very few furnaces have any ability to modulate the flame, so it's either on or off. In all likelihood the on/off time varies with the return air temperature (and thus, the heat load.)

The post-burn run to cool the heat exchanger after the call for heat is satisfied is certainly standard.

Your Answer

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

Not the answer you're looking for? Browse other questions tagged or ask your own question.