Patent attributes
Apparatus and methods for providing fluid such as water at a controlled temperature. In some embodiments, hot and cold fluid is provided to a thermostatically controlled mixing valve, which then provides fluid at a mixed temperature to a plumbing system. The thermostat provides a first loop for closed-loop control of fluid exit temperature, and preferably there is a second, electronically controlled closed loop for adjusting the temperature of fluid exiting the valve. In yet other embodiments the electronic control loop is fail-fixed, such that a loss of electrical communication to the actuator results in the actuator maintaining its last position. In yet other embodiments there is a system including a flow sensor and a recirculation pump such that the temperature of the fluid exiting the valve cannot be adjusted if there is insufficient flow, or if the pump is actuated.
