Abstract: A vertical tube water heater comprising a water tank within which are located a plurality of tubes and a vertical combustion tube provided at its upper end with a burner, the bottom ends of said tubes and combustion tube being in communication with a chamber located at the bottom of the tank and the upper ends of the tubes being in communication with a header chamber located at the upper end of the tank and which is in communication with an exhaust duct, the arrangement being such that when the water heater is operating at low temperature settings any condensation formed within the tubes is evaporated or drained and can not reach the burner to extinguish it or its pilot light.

Abstract: A vertical tube boiler having a plurality of vertical tubes which extend through a water tank and communicate with a combustion chamber and a chamber provided with a flue outlet, the tank being provided with a transverse plate located above the bottom or firing plate of the tank and provided with holes 20 through which the tubes extend with a clearance gap being provided between the periphery of each hole 20 and the outside of the associated tube, through which gaps water flows upwardly to create upward currents in the water within the tank to hold any scale removed from the outside of the tubes in suspension and if such scale drops to the bottom of the tank, then it accumulates on the plate and not on the firing plate thus preventing burning out of the firing plate.

Abstract: Apparatus for cleaning the interior of the tank comprising a spray head which can be inserted into the tank, the head having spray arms which are rotated about a vertical axis by a shaft driven by a motor and are rotated about a horizontal axis through only substantially 180 degrees by gears in mesh with gear racks carried by a frame connected by a piston rod to a piston movable within a cylinder attached to the underside of a plate which mounts the spray head to the tank, the spray head being fed selectively with water from a tank and chemical cleansing liquid from a tank by a valve controlled system which includes a heater for heating water and a heat exchanger for heating the chemical cleansing liquid, said system including a pressure pump for supplying the water and liquid to the spray head and a scavenge pump for removing liquid from the tank.