Well, I replaced the VanWert 1200 with an EFM 520. I solved the issue of breakdowns - I hope - but not of how the coal is burning. I was blaming the Van Wert, but it seems to be burning about the same.
The problem is that we are producing way too much ash. The ash also seems to not be all ash, some parts look like charred coal or rocks. More info that may or may not be relevant: The coal is undersized Buck, not Rice, but seems to burn about the same as in the Van Wert. The house temps are set around the mid-60's. We don't have programmable T-stats, so we adjust manually, occasionally. I don't know what the other stoker settings are, but we do have a damper.
The house is an old barn/carriage house. It is built into the side of the hill, so the basement is on one level on the mews and the main house is on the street level. The basement is stone, and the doors down there are very drafty. The windows on the house are old, single pane, and are somewhat loose. Most are covered by storm windows. There are three circulators, one to the basement (the temp is turned way down) and one to each side of the house, which used to be divided in two. The house is about 3500 sq. feet, including the basement, which is unfinished and uninsulated, other than the stone.
The house was originally clapboard, with aluminum siding on it when I grew up in it. I removed the old siding and put up cedar shakes over the clapboard. I tried to put put blueboard but the contractor ran into problems with the depth and the other trim. The walls have super old insulation - I think it's cellulose or something like that. I spoke to a contractor about trying to plug some of the leaks in the doors, basement windows, etc. Other than replacing the windows, I don't think major insulation is possible, and that's not on the list of things I can do right now.
The house is warm with the t-stats set at mid-to high 60's, unless it's in the single digits outside.
We just seem to be plowing throught coal. My bin takes about 7 tons or so, and it's going down fast. I was blaming the VanWert, but maybe unfairly. The ash, as I said, is not all coal ash. In short - please, from the experts - any suggestions on settings, tweaks, etc? I have been using coal all my life, but am fairly ignorant about stokers. Maybe it's the coal. It seems sinful to waste so much of it, but if it can't be burned, it can't.
We are going to try slowing down the feed, on the theory that it will have more time to burn. Any other thoughts (keep them on a "Coal Stokers for Dummies" level, if possible) would be greatly appreciated.