im just wondering about getting from 0 degree days to say 70 degree air. Im planning on changing my stack and probably scrapping my heat saver. I had one of my stack elbos come a bit loose the other day, and oddly enough, very little smoke was comming out of the crack. Before I retightened it, I walked out and looked at my chimney top and noticed way more smoke there. So I assume that much of my smoke comes from creasote inside the stack either from idling allot or some from the heat saver.