Abstract: A system having a microprocessor to provide an adjustable control of the temperature and pressure of water at the outlet of a single adjustable valve. The water temperature at the valve outlet is constantly monitored. A processor compares the actual water temperature with a specifically requested temperature for the water at the valve outlet, and provides signals to relays and a control circuit for a motor which adjusts the temperature of water by the relative proportions of hot and cold water discharged through the valving to the outlet. The system with the microprocessor provides a multi-speed control of the motor having variations in the speed of adjustment of the valve so as to effect a quick valve movement to a temperature in the vicinity of the desired temperature after which fine tuning provides the exactly requested temperature.