I have a Keystoker Hearth stove purchased used a number of years ago.
The stove is red with brass trim. It has an entirely flat back on it with the fluepipe exiting through the back at floor level. The front of the stove has three sides to it: the center one with a glass door into the fire box and below this a door about seven inches high to remove the ash pan.
I have always had a problem with keeping the fire on the burner tray (is this called a "grate" in auto-stokers also?).
Here's what happens:
1) The burning coal tends to slide off the burner tray into the ash pan. This reduces my heat output dramatically and I end up with partially burned coal in the ash pan. Additional coal being fed by the pusher causes more coal to slide into the ash pan. It's like the burner tray is TOO smooth.
2) The ashes building up on the burner tray which causes the coal to be heaved up behind the burning coal and ashes into a layer as thick as the sides of the burner tray. When this happens, the heat output is reduced significantly. The pusher gradually moves the entire mass of ashes and coal down the tray.
When the ashes fall into the ash pan, the burning coal fire keeps dribbling down also. I end up with a significant amount of partially burnt coal in the ash pan.
I called Keystone several years ago about this problem. In the case of number one above, he said if the stove was exactly level and this was occuring, I should raise the left side of the stove a quarter of an inch (1/4"). He said this would change the angle of the burner tray a few degrees (toward the horizontal). I did this but I end up with second problem above occurring more often.
I think the gentleman at Keystone also said that there should be about 1/2" freeboard on the burner tray. The few times that this occurs, that is that there is a half inch of the sides showing above the burning coal, I get GREAT heat output and great fuel economy.
Also, I do not have an owners manual for this stove. If anyone can email me a copy, I'd appreciate it.