Abstract: A wood burning stove includes a water circulating grate within the stove fire chamber which includes horizontally extending, vertically spaced, first and second tubular manifolds. Fuel supporting pipes, including bottom portions which define a "V", physically and fluidly interconnect the manifolds. An inlet pipe extends throughout the majority of the length of the bottom manifold, and the top manifold is connected--through a container having a larger cross-sectional area than the cross-sectional area of the manifold--to an outlet. The inlet to and outlet from the manifold are connected up to a hydronic space heating system. The container supports a heat exchanger comprising a finned copper tube, so that the heat exchanger extends generally horizontally and within the first manifold. The heat exchanger is connected up to a domestic hot water supply. The container also supports one or more electric resistance heating coils, which heat liquid within the container in emergency situations.

Abstract: A fluid heating system specifically designed for the use of solid bulk fuel, such as wood or the like. The burner unit includes a continuous coil of fluid carrying conduit which acts both as a grate for supporting the fuels of combustion and as the primary implement for circulating fluids in close proximity to the combustion material so as to maximize the heat absorption by the fluid. Primary and secondary combustion air inlets combine with a baffling system that maximizes the efficiency of the combustion process within the heat transfer coil. Room heating and hot water storage apparatus are also disclosed as desirable end uses for the heated fluid.