Op4_camper wrote:[quote="Dennis"]welcome,I believe your furnace along with all the US Stove/furnaces have a built in secondary draft in the firebox walls.Use the search button, top right corner and search for "burning bit. in a clayton" and read the "sucessfully burning ant in a clayton" this will give you a better understanding of using/burning coal in your furnace.The USS furnaces burn wood great, but are finiky burning coal, good luck and ask if you need help
I cemented those air passage in so the air don't by pass the fire.
He's burning bit. coal, so he needs some secondary draft[/quote]
I burn both I use the feed door vent for that with bit.
The problem with this stove is ash build up. There's a one inch ledge around grates and it builds up fast. I have a piece of rebar that I slide down both sides.
Also I only use the door when loading and for about twenty minutes after. Then I shut it and turn ash door back to about half to one turn open.. It's 21 degrees out house is 73. Its my only heat in this house. I yanked out oil furnace because I kept using it ,I would get lazy and burn oil.
When I first got stove the heat output sucked. Much easier and better since I cemented those air passages.
Of course that's what worked for me can't say for anyone else.