Abstract: A venting system for the combustion chamber of a gas-fired heating plant has an elongate diverter box arranged vertically of the heating plant exteriorly thereof and having an upper portion and a lower portion with the latter having a bottom provided with a substantial opening disposed well above the base of the heating plant for the free admission of atmospheric air surrounding the heating plant into the diverter box and with the upper portion having selected openings for the reception of horizontally disposed pipings from the flue outlet for the combustion chamber and for the chimney flue with a vertical baffle depending from the closed top of the upper portion a substantial vertical extent into the diverter box and dividing it into a flue outlet section and a chimney flue section with said sections having thermostat means to indicate exteriorly of the sections the temperature of the gases therein and with a safety limit switch housed in the flue outlet section below the lower free end of the baffle and bei

Abstract: A venting system for a warm-air furnace, gasfired boiler or the like heating plant has an open bottom diverter box which is arranged horizontally externally of the heating plant substantially at the level of the top thereof. The top wall of the diverter box at one end section thereof is connected by a vertically upstanding U-shaped, internally unobstructed, ducting to the top of the combustion chamber of the heating plant so that fumes flow therethrough into such combustion chamber end section of the box while the top wall of the diverter box at the other end section is connected by a vertically upstanding, internally unobstructed, piping to the flue.