I have had this stove for two years and just a few weeks ago the insert smokes when opening the door. I tried re cleaning the flue liner only got a small amount of klinker out of it. But it still smokes when opening the door. Now this year we had an addition added to the main floor and I think this causes a back draft. The addition is about 600 sq ft and only heated to 50* at this time, it also has a vent fan in the bathroom. I think this is the cause of my troubles the question is how do I solve the issue of the draft? Eventually the new room could be sealed off but it is my bedroom and the insert can heat that also. When it is completed and up to temperature will this solve the problem? Sorry for the long post but I would like to get answers before the construction is over and the construction crew leaves.