A plastic ball float is connected to a high or low pressure lever action float valve which either rises or falls depending on weather the tank is emptying or filling. When the tank empties, the float falls and the arm which is connected to a washered “Piston” retracts from the “Seat” of the valve causing the water to gush in. Conversely when the float rises; the piston slowly closes against the seat and shuts off the water supply. Plastic floats are acceptable when there is no danger that hot water could ever enter the tank. In all other circumstances, it should be made from copper.