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?
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.
We had a furnace that did that... seemed much more economical to burn 1,500cfm for 3min., off for 1min., 1,500cfm, 1min off.. finishing on the fourth cycle. Than is consistently running 1,500cfm for 15min., non-stop %^)
