a few times the past couple of weeks, after turning thermostat up the furnace fires up, ignites pilot, a few seconds later the 3 burners kick in and a few seconds after that the registers are blowing out hot air. The problem is SOMETIMES after runnng awhile there will be a "pop" almost as if a backfire and the burner flames are put out. Furnace will continue to run but without burners so eventually the air leaving registers is getting cooler and cooler
Any ideas ??? Thanks .../gary
Any ideas ??? Thanks .../gary