Abstract: A hot water tempering system for use with a standard water heater storage tank includes a heat exchanger interposed between the hot water outlet means and the cold water inlet means for transferring heat from hot water exiting from the tank to cold water entering the tank. In this way the temperature of the hot water is tempered. The system is characterized by the fact that the cold water inlet means comprises a first conduit which passes through the heat exchanger to receive heat transferred from the hot water, and a second conduit which bypasses the heat exchanger and delivers cold water directly to the tank. The two inlet conduits are connected to a cold water mains inlet by way of a diverter valve which, in response to the water temperature in the upper region of the tank apportions the water flow between the two conduits.

Abstract: The invention provides a self-contained automatic temperature-responsive three-way line valve. A tubular valve member is axially slidable between first and second limit positions for selectively directing fluid from an inlet port to a first outlet port or a second outlet port. The valve member is disposed between a pair of opposed compression springs, one being a conventional spring biasing the valve member to the first limit position and the other being an SME spring which overcomes the bias of the first-mentioned spring when the fluid exceeds a given temperature.

Abstract: A fluid tampering system for use with a standard water heater storage tank includes a heat exchanger which interposed between the outlet means for conveying heated fluid from the storage tank to a distribution system and the cold fluid inlet means, so that heat energy is transferred between heated fluid exiting and cold water entering the storage tank. Preferably, the heat exchange is complete and water exiting the heat exchanger in both the inlet and outlet conduits are of about equal temperature. In order to avoid the water exiting the water heater to the distribution system becoming too tepid, a bypass conduit either in the inlet means or in the outlet means may be provided triggered by a bypass valve located in the outlet conduit. As a safety feature, a safety shut-off valve is located in the outlet conduit before the distribution system to automatically shut-off the conduit where water exiting the system is above a desired maximum temperature.