Abstract: A heat storing fireplace including a fire-box surrounded by a heat storage medium which is either an enclosure containing a material having a high specific heat such as sand or gravel or a large number of heat conducting bags containing a high specific heat material. Exhaust gases are conveyed from the fire-box to an exhaust outlet by several conduits extending through the heat storage medium in a circuitous path in order to transfer heat from the exhaust gases to the heat storage medium. Heat is further distributed through the storage material by a heat conducting lattice fastened to the conduits and extending through the storage medium in a circuitous path. Combustion air enters the bottom of the fire box through a combustion air inlet jacket surrounding the exhaust outlet in order to simultaneously pre-warm the combustion air while thermally insulating the exhaust outlet from its support structure. A draft is created through the fire-box by an exhaust fan mounted in the exhaust outlet.