Abstract: A sheet metal inner fire box, has a grate, surrounded by refractory border in its bottom portion. Air, from an air intake port, in the front of the stove, passes upwardly through the grate and, thence, out of the discharge flue. An outer jacket houses the fire box and has walls which are spaced by baffles from the walls of the fire box to define an air plenum through which a blower directs the air to be heated. Water coils in the plenum are connected through a pump to the hot water heater.