The present application relates to improved valves, especially valves for plumbing fixtures, fittings and water supply systems and installations for washing, showering, bathing and the like employing such plumbing fixtures and fittings, are disclosed herein. The concepts have particular, but not exclusive, application to a mixer valve, especially to a thermostatic mixer valve and, more particularly, to an electronically controlled thermostatic mixer valve. In other embodiments, the concepts may be applied to flow control valves and to applications of such flow control valves in plumbing fixtures and fittings and parts thereof including, for example, a mixer valve.