Abstract: A power production system is disclosed. The system includes a firebox, and fluid-containing heat transfer coils at the firebox sides. The heated fluid is conducted to a transducer for converting that heat into mechanical work. In the illustrated embodiment, the transducer includes a piston and cylinder arrangement. A converter is disposed adjacent the firebox to receive heat and the gaseous products of combustion from the firebox. The converter chemically converts the gaseous products of combustion into less objectionable materials.