Alright mate, all the above sounds right, on mine there was a open and shut grill on the bottom to collect the ash! im sure you have cleaned it and leave it in the open position, the baffle on the top leave that open to, sounds like there isnt enough air being pulled in through the fire itself ie: like above leave the window open give that a go, when we build houses we always make the chiminy 1.2 meters above the ridge or .6 of a meter below? a down draft will cause you big trouble and some work to the chimney will have to be done. my personal opinion is the stailess flue liner is good but won