av8r wrote:Would it be possible for someone to burn enough anthracite coal in one season in a stoker to create enough flyash in the pipes to reduce the draft even a little? I would think you'd need a pretty significant accumulation of ash in a 6" pipe to reduce the small amount of draft required to run one of these stoves. Maybe I'm wrong.
Yes would be the answer. Some installs will have relativly no accumulation in a year and some may need to be cleaned 3 or 4 times a season. The only way to know is to get in there and clean it to see what is there. Once you know, you can determine how often yours needs to be cleaned. It doesn't take a lot of ash either, again, it depends on a lot of factors. Be safe and clean it, then you will know.