Blower kicks on and runs for a few minutes before Gas comes on and everything is normal and then the flame 'gushes' gas and you can see bright flame inside it (while cover is on) and then it goes back down to normal (this has been since this year). It has also had to be turned off twice tin January at fuse box because temp at thermostat showed house at 57 and furnace igition had to be turned off and then back on then back on at fuse to get it to work
Sounds like could be a couple of things, I've had the same problem w/our older LP furnace. Usually is a thermocouple if you have a standing pilot. There are usually 2 Auto Limit switches mounted on the housing facing the burner, sometimes under a small housing above the burner. 1 triggers the burner & blower on & the other trigger it off. Sometimes they have a small adjustable dial on them to set temp & sometimes not. They usually only have 2 screws to hold on & cost somewhere around $15 each. Otherwise burner may be defective. Description & model # would be good.