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: 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.