Abstract: A system and a method for controlling a pump in a recirculating hot water system is provided. In one embodiment, the invention relates to a method for controlling a temperature of water in a recirculating hot water system including a storage tank for storing heated water, a recirculation conduit including a supply conduit for supplying the heated water to users via a plurality of outlets having a first outlet and a last outlet and a return conduit for returning an unused portion the heated water to the storage tank, a pump for circulating the heated water, the pump disposed along the return conduit, the method including measuring, at a point along the recirculation conduit, a temperature of the heated water provided from the storage tank, and controlling a speed of the pump, disposed along the return conduit, based on the measured temperature.

Abstract: A system and a method for controlling a pump in a recirculating hot water system is provided. In one embodiment, the invention relates to a method for controlling a temperature of water in a recirculating hot water system including a storage tank for storing heated water, a recirculation conduit including a supply conduit for supplying the heated water to users via a plurality of outlets having a first outlet and a last outlet and a return conduit for returning an unused portion the heated water to the storage tank, a pump for circulating the heated water, the pump disposed along the return conduit, the method including measuring, at a point along the recirculation conduit, a temperature of the heated water provided from the storage tank, and controlling a speed of the pump, disposed along the return conduit, based on the measured temperature.

Abstract: A system for controlling a water heating system senses the temperature of new (unheated) water and uses any drop in that temperature as an early, quantitative measure of the demand for hot water within the system. The heater itself is turned "on" and "off" with respect to a control set point temperature (T.sub.C) which increases with decreasing inlet water temperature. Thus, the control set point is increased above a baseline by an amount related to the amount of unheated water drawn into the heater to replenish the heated water being used. In a preferred embodiment, a calculated demand value proportional to the drop in inlet water temperature (T.sub.I) is summed over time to reflect the time during which a given demand condition continues. When the heater is ultimately turned "off", signifying that the hot water supply temperature (T.sub.S) is substantially higher than the control temperature (T.sub.C), the control temperature is reset to its baseline value.