I know the answer to this question has to be here somewhere, so forgive me for bringing it up again. I am new to coal burning. I am burning deep-mined nut coal in my Gibraltor coal stove. I can not keep my coal fire burning longer than 4 or five hours without attention. It doesn't matter if I keep the damper open or closed the fire goes out. I only keep about 3 to 4 inches of coal in the box at a time. Perhaps I need more. The fire bricks are about 4 inches higher than the coal. As the fire goes out there are patches of darkness where there is just ash mixed with unburnt chips of coal. Also I was wondering as I close the damper, what is a healthy coal fire supposed to look like if I expect it to burn for about 8 hours? Should all the coal be glowing red, or should the tops of the coal nuggets be black with a bright orange bed underneath?
There seems to be a lot of unburnt coal chips mixed in with the ash. Is this common?
Thanks for any help,