Leonard Valve officially began manufacturing thermostatic mixing valves in 1911, and was incorporated in 1913. The founder, Frederick C. Leonard, was a watch repairman and electrician, among his many talents. The story goes that Mr. Leonard would frequent barber shops for a clean shave. Trim after trim, he became disgruntled when the warm towel that was used to clean his face was either scorching hot or lukewarm, and thus began his quest to develop a device that could provide stable hot water temperatures.