I've been burning a coal mix I got for free from someone who no longer burned coal in my Kodiak with pretty good results. It is a mix of sizes, from about 3" down to dust and everything in between. It is not very shiny, I'm guessing bituminous or softer anthracite. Anyway, I am emptying another basement from someone who gave up on coal. This is clean nut coal, shiny hard anthracite. It does burn cleaner when thrown on the fire, but I've been having some troubles with it. In the morning, the fire is out. It just looks like all of the coal is painted white and orange and still where I left it the night before. After a day or so of this I discovered that the bottom 4" or so of the coal bed was solid clinker. It seems as though very little ash will shake through the grate and is harder to get to full temperatue. I thought hard anthracite was better, why am I having do much trouble? I kind of got thrown into this when my oil burner blew up and I'm trying to learn on the fly. Thanks in advance for your help.