I have always found it weird that my harman xxv didn't have an exhaust blower gasket. It seems odd to me, you have to silicone the whole exhaust system that is inside your house. The nipple that attaches to the stove has a gasket. but the exhaust blower has nothing. Is it because it is considered to be under negative pressure? i mean it is a metal to metal mate, if anything isn't perfectly flat or perfectly sized you will get a leak. if the blower mounting area is under negative pressure your blower could be pulling room air through the potentially drafty exhaust blower mounting area, instead of pulling it through the combustion chamber. Anyone have any thoughts on this? Anyone ever make a gasket for their harman?