I have been running pellet stoves since 1996 and i thought i had a good eye for what the flame characteristic looked like. well i finally bought a gauge and set my stove per the manufactures direction and what a difference it has made my ef3 is running like a champ glass is staying cleaner less pellet usage. And by looking at the flame i would have given more air so spend the the 45 bucks and get a nice digital meter and set the stove like it should be