Abstract: A low profile, high efficiency, fireplace boiler wherein a burner tray supports a number of gas fired burners and artificial logs within a hearth area of the firebox and about which logs the gas and flames are distributed. Combustion air is drawn from a conduit that surrounds an exhaust conduit at a chimney and circulated via a distributing manifold to the space beneath the burner tray, where it mixes with the fuel. Additional secondary air is directed from ports at intersecting levels of the tray to create flickering. Heated exhaust gasses are directed by a baffle to contact exposed walls of a liquid filled heat exchanger formed into the top and rear walls of the firebox and to pass through the bottoms of a number of vertical plenums mounted within the heat exchanger behind the baffle. A spring biased explosion door is provided beneath the burner tray. Liquid is circulated through the heat exchanger to distribution conduits arrayed about the premises.

Abstract: A single port, internal liquid heat exchange assembly for heating domestic water from a free-standing, low pressure wood fired boiler. A threaded manifold fastener retains the assembly in suspension within a single access port of a conventional water heater. An elongated manifold contains first and second coaxial flow columns which terminate at exposed inlet and outlet ports and communicate with each other within the manifold. Constructions are disclosed having concentric flow columns, convolute and expandable manifold walls, internal bypass ports, vibration dampeners, multi-ported flow transition zones and which may include a sacrificial anode.

Abstract: An outdoor, self-contained wood fueled furnace. The furnace includes a non-warping, laminated sheet metal door; a rear exiting flue with water discharge means; and a baffled, heat exchanger which surrounds the firebox. The door, particularly, includes an external panel which is secured with a single pin to a crossbroken first panel. An insulator is secured between the first panel and a second interior panel, and the first and second panels are riveted to each other.