Now I know why I cant hold a temp below 225 I just foud a horseshoe shaped crack on the dome rim and the wife found one on the base running from the rim down to the fire vent air intake door. Looks like I will calling headquarters tomorrow. I already have swaped this out once before like about three years ago because of a rim level defect. now this plus not too mention a cracked fire box which is the 3rd one. If the damn thing has to keep being changed out what the hell is the use in having one very discouraged.