We have a BIS Nova ( now Lennox, I understand), installed 3 years ago- and we seem to a much more noticeable smell of smoke than the previous 2 winters. We open the door ajar, to get smoke moving up chimney before re-loading with wood, but that doesn't always prevent smoke from billowing out into the living room. We have a fan, and a couple of ducts to spread heat to another room. The other room sometimes has a coat of ash on the furniture right below the grate...is that to be expected? Or could that be a symptom?