Abstract: A hot water recovery system includes a hot water source; a hot water delivery line connected between said hot water source and at least one plumbing fixture along with a cold water delivery line connection between said plumbing fixture, a cold water source and said hot water source; a pump, interconnected between said hot and cold water delivery lines, enables circulation of water from the hot water delivery line through the cold water delivery line and into the hot water source, thus eliminating the need for a separate recirculation system. A control system causes the pump to circulate water from the hot water line into the cold water line and back to the hot water source when a hot water valve on said plumbing fixture is turned on; and a temperature sensor stops the pump, via the control system, to prevent heated water from being circulated through the cold water delivery lines.

Abstract: A demand recovery hot water system in accordance with the present invention provides for return of hot water from a plurality of plumbing fixtures to a hot water source. A transfer tank is provided with a movable piston which enables circulation of hot water without significant loss thereof. Continuous circulation is not required thus reducing operating costs.

Abstract: A plumbing system in accordance with the present invention provides for accelerated hot water delivery to a plurality of plumbing fixtures from a hot water source. Flow switch means are provided to enable a pump to circulate hot water to the plumbing fixtures in response to water being withdrawn from a plumbing fixture. In addition, the hot water source may include a hot water recovery apparatus for withdrawing hot water from circulation pipes subsequent to cessation of water flow from a plumbing fixture.