Abstract: The fireplace heater is adapted to be placed in a normal fireplace opening and functions as a heat exchanger through which room air is passed for indirect heat exchange with the combustion products. The heater includes a firebox which is mounted on a front frame member, and an outer frame or wrapper which is spaced throughout from the firebox to provide channels or passages through which the room air is directed for heating the same. The front of the heater includes side and top panels which are constructed and arranged to provide an airtight assembly.