Abstract: A wood burning furnace includes a combustion enclosure made up of a lower closed generally rectilinear fire box which is defined at an upper portion thereof by a semicylindrical roof dome and a top cylindrical-shape smoke chamber supported on a rearward upright cylindrical smoke conduit and a forward upright smoke conduit, these conduits being supported on the fire box roof dome and open between the smoke chamber and fire box. The combustion enclosure is supported inside of a furnace shell above a fan compartment in that shell. The furnace shell and heating air baffles fastened to it are so constructed as to provide a heating air passage between the combustion enclosure and shell, and a blower in the fan compartment forces air from outside of the shell over the surfaces of the combustion enclosure and out the top of the shell to a location for use of heated air.