I realize the glass is going to get dirty...im trying my luck with a used 4 year old Pel-PRO pellet stove,,,only used about 4 hours with a bag of cheap pellets that came with it..but main question is..Glass is pretty sooty and darkish brown...i did clean before using..but with clean streaks coming up glass about half ..sorta like there is air possibly leaking in that isnt suppose to?Read a few posts about air wash but this isnt one that has it or at least not mentioned in manual...so is stove sucking in air possibly and if so im sure this needs to be fixed and will effect running of stove