hello guys new to the site . it is a great one at that.my ? is i have a insert that i installed last year for when it gets real cold ,but the bad thing is it smokes when every the door is open up . it is a lile 2 door the flue is clean as a whistle and is higher than the roof. i have even added a extra piece 4foot higher than the top of roof. what would make it smoke any help is appreciated.