Abstract: A combustion heating device for use for example with oil processing equipment defines a combustion chamber within which combustion wholly takes place. The combustion chamber consists solely of a sleeve and end plate defining a vertical cylinder and a layer of ceramic fiber insulating material inside the sleeve defining the inner surface of the combustion chamber. A burner is mounted in a bottom plate of the device which can be pivoted to an open position exposing the burner for service. Air channels are defined on the outside of the sleeve so that incoming combustion air passes over the sleeve and acts as a heat recovery for any heat escaping from the insulating material. An outlet duct at an upper end of the combustion chamber at right angles to the combustion chamber extracts the combustion gases so that all heat exchange takes place outside of the combustion chamber. The device improves heating efficiency and reduces corrosion of heat transfer surfaces.