Tempered water mixing system

A tempered water mixing system, comprising:

• a main mixing valve having a cold water inlet, a hot water inlet, a discharge outlet, and thermostatic blending means for blending cold and hot water inflows coupled respectively to said cold and hot water inlets to provide a tempered water discharge outflow at a selected temperature level at said discharge outlet;
• a cold water supply conduit for supplying cold water to said cold water inlet;
• a hot water supply conduit for supplying hot water to said hot water inlet;
• a discharge flow conduit connected to said discharge outlet;
• a high temperature limit valve connected along said hot water supply conduit and including means responsive to the temperature of said discharge outflow for modulating hot water flow through said hot water supply conduit to prevent the temperature of the discharge outflow from exceeding a preset upper limit;
• and
• a flow control valve connected between said cold water supply conduit and said discharge flow conduit and including means responsive to the pressure differential between the cold water supply and said discharge flow outlet conduit to permit a bypass flow of make-up cold water from said cold water supply conduit to said discharge outflow conduit when said pressure differential exceeds a predetermined limit.