Berlin wrote:A combustioneer is an underfeed stoker furnace designed for burning bituminous coal. It has a hopper that holds well over 150lbs of coal and self-contained auger etc. The combustioneer 77b is fairly common as it was manufactured in large numbers by Will-burt mfg. for decades. They stopped production sometime in the late 80's if I recall correctly. 77b combustioneers are almost identical over the years. They extremely heavy well-built units; other than replacement of transmission seals and a re-wiring when I first purchased it, mine remains working w/ out replacing of any other parts since 1972 when it was made.
They were initially sold as a space heating "stove" with an integral fan; I recommend NOT using them like this at all. I recommend using them as an add-on furnace. The way they were manufactured allows for effortless conversion to forced air furnace: remove vent on top (slides off), attach hot air plenum. Remove fan on back (four screws, two wires) and cover opening w/ sheet metal. Install direct-drive squirrel-cage fan from craigslist etc. (usually less than $50 in good working cond.) on the left side of unit about 8" up from bottom (cut hole in sheet metal size of fan outlet). Make cold air return plenum around fan and screw to side of unit. attach wires from fan control and you now have an inexpensive, excellent, stoker furnace that burns inexpensive bituminous coal. Tend once/per day.
How well do they work with anthracite?
They work ok, but not as well as an anthracite specific appliance - They are a clinkering type stoker, so, the clinker has to be pulled from the ash on the hearth into the little ashpan in the stove once/day or every other day in mild weather; an anthracite appliance can go much longer in mild weather because of it's (usually) large ash pan. Anthracite will produce more ash as well; one of the nice things is that it melts ash from bituminous coal (usually less ash than anthracite by a few %) into a small compact chunk of iron/glassy rock, anthracite's higher fusion temp will produce more loose, volumnous ash and prevent as good a clinker from forming for easy removal. I've burned about 2-1/2 tons of coal so far this season and have just filled one 33 gallon trash bin to the top with clinker as of yesterday; now that bin is heavy, but the volume is not bad for the amount of coal burned.
They work w/ wood pellets too, but, there's no reason to burn anthracite or pellets in this furnace, it burns bituminous coal well and for far less cost than anthracite or pellets.