I have been burning for just one year and the Jotul 550 wasn't drawing very well. OK last year my wood wasn't really dry, so I resplit it and let is cure in the house for two weeks. I got good fires and no smoke out of the chimney. Fast forward to last week, every time I opened to refuel the house filled with smoke. Yesterdat I went ot my great stove dealer and was outfitted with flexible rods and a poly something brush. I cleaned the liner and only got 3/4 of a gallon of crystalline junk out. Looked like klinker. I resealed all the joints let it cure for an hour and fired it up real slowly. No smoke and a really nice fire. So what did I do that caused the major difference, cleaning, resealing removing the internals. It works but I really am at a loss what I did that made that much of a difference. Yes I an a bit of an over analyzer, the kind that wears A BELT AND SUSPENDERS TYPE.