Abstract: An assembly for use in a system for heating water comprises a heat exchanger for heating cold water to produce overheated hot water and a blending chamber in which the overheated hot water is mixed with cold water to produce blended hot water. An inlet valve controls the flow of cold water to the heat exchanger. A bypass valve controls the flow of cold water into the blending chamber. A flow restrictor restricts the flow of cold water from the bypass valve into the blending chamber when the demand for blended hot water increases above a predetermined amount.

Abstract: A control valve assembly 10 for use in a system for heating water is disclosed. The system includes a source of steam 12, a steam condensate trap, a source of cold water, a heat exchanger 14 to transfer heat from the steam to the cold water, and an outlet where heated water is used. The control valve 10 assembly includes a dual valve structure which splits the flow of incoming cold water, directing one portion of it to the heat exchanger 14 and bypassing the other portion of the incoming cold water around the heat exchanger. The two portions of the incoming water rejoin in a blending chamber 16 which is connected with a water line to supply blended hot water to an outlet such as a shower or faucet. A controller 36 within the control valve assembly 10 is responsive to the demand for blended hot water.