i burn 24/7 when it gets cold....really the the only heat i use...i cleaned the chimney yesterday with the sooteater....man was i suprised...brown powder cam out of the chimney..enuf to fill maybe 2 shot glasses.....and then the only black soot came from the chimney cap...about 1/4 of a coffee cup....the soot eater broke off in the cap and went flying...ended up in my gutter...thats a different story...but i didnt know it was in the gutter i thought it was stuck in the chimney...so a neighbor came over and got on the roof to look for it in the chimney(i dont do roofs)...well we figured out it was in the gutter eventually...but anyways he told me the chimney was spic and span clean.....man am i ever pleased with what i found from a 1 year cleaning..