A bypass valve is for support between hot and cold water lines that connect to respective hot and cold fixtures. The bypass valve includes a valve body having an internal chamber, a hot water inlet port, a hot water outlet port and a discharge port; a bi-metal spring; a support member for mounting the bi-metal spring within the internal chamber of the valve body; and a shuttle mounted to the bi-metal spring and constructed and arranged to mate with the discharge port in a closed position of the bi-metal spring. The bi-metal spring assumes an open position to disengage from the discharge port at a predetermined water temperature to enable the hot water to discharge through the discharge port to the cold water line.

Temperature control device (1) has a hot water inlet (12), a cold water inlet (14) and an outlet (16) for tempered water. A diffuser (18) is provided in the device (1) to disrupt the flow of hot water after it enters the device (1). The disrupted hot water emerges from the diffuser (18) into a chamber (20) in which it is melded with cold water that is able to enter the chamber (20) from the inlet (14) when a piston (22) is spaced from a seat (24). The melded hot and cold water result in tempered water that is discharged from the outlet (16). A temperature sensitive device (26) is provided, which is responsive to changes in ambient temperature. A temperature setting mechanism (52) is provided which is operatively associated with the temperature sensitive device (26) and permits the maximum temperature of the discharged tempered water to be adjusted.