My first year of using my wood boiler with a 7X7 clay liner resulted in alot of creosote. It was even growing outside the top of my 25 foot chimney. Except for initial firing of wood, the stack temperature was hanging around 150 degrees.
I ordered a smooth, rigid, stainless liner from Olympia in Scranton and applied 1/2" of ceramic wool around it and dropped it down the chimney last August. All of this winter, it was burning at the same 150 degrees and I was wondering how the chimney was looking. So, yesterday I cleaned the pipes and looked up from the bottom and was pleasantly surprised to see no creosote or anything at all inside the liner. I might have removed two cups of white ash from the base. The insulated liners really work.