Abstract: A water and room heating unit for extracting heat from combustible material. The heating unit includes a firebox chamber formed from a plurality of water chambers that are arranged in a U-shape and are interconnected by a first network of pipes which also function as grates and a second network of heat extracting pipes having radial fins projecting therefrom. The firebox includes an air combustion control and a flue for extracting heat from the combusted gases to heat the surrounding atmosphere.