It barely cracks open, too much flow. So it closes again, repeating the process over and over. Without adding valve speed controls, the quick vibration can sound and feel like a machine gun. You just exchange one set of problems for another. Electronic options such as variable speed pumps offered by companies like Franklin, Goulds, Grundfos, Hays, Meyers, and others also have minimum flow problems.
Small leaks can cause destructive cycling.
With high purchase cost, and complicated electronics, these super high RPM pumps are not likely to pay for themselves in energy savings. These small variable speed pumps have all the same problems as any variable frequency drive. The most dependable water systems use heavy duty, standard speed pumps and motors that have long been the established and proven mainstay of reputable pump and motor manufactures. The simple patented design of the Cycle Stop Valve is the only design that contends with all the problems associated with other types of pump controls. The Cycle Stop Valve insures minimum flow to cool the pump and motor.