Abstract: A heating system providing an instantaneous source of hot water to either a water sink or to a source of heat or to both. The system includes means for receiving cold water and converting it to hot water where the cold water is converted to hot water essentially instantaneously, obviating the need for a water storage tank. The heat in the water is converted to a source of space heat utilizing a water to air heat exchanger. The system also includes means for directing the flow of hot water to the water to air heat exchanger in response to a demand for heat signal, and means for directing the flow of hot water to hot water sinks. A flow rate detector monitors the flow to the sink and provides a signal indicative thereof.

Abstract: A fluid flow rate detector for controlling an electric switch in a circuit for regulating fluid flow, the detector including inner and outer portions where fluid is received in the inner portion and flows out into the outer portion through perforations in the inner portion. A magnetic slug is disposed in the inner portion and moves away from a home position in the direction of fluid flow when the flow exceeds a predetermined rate. The slug then is deposited in a zone between the perforations and an end cap of the inner portion so as to permit the flow of fluid to occur at a substantially unimpeded rate. A magnetically activated electric switch responds to the movement of the slug and opens and closes an electric switch in response to the fluid flow rate. The detector can be used in a system dually providing a source of hot water to a hot water sink and to a source of heat.