My Harman Magnum keeps burning itself out. It burns all the way to the hopper. I have it set according to the posts here, plus experimenting. The coal IS dry. I bought it in July and it's out of the weather. Here's what happens. At 1:30 this morning, it was burning perfectly. At 5 AM the fire was down to about an inch long and flames an inch high, all the way to the rear. The feeder is going and it's calling for heat, but no coal is pushing. When I empty the hopper, it's very damp, wet at the bottom, and I smell sulpher. This happened the same way about 5 times in 2 days. I push fresh coal through the feed area and it starts going perfectly again, then the same thing happens. Does anyone have any suggestions?