A method, system or computer usable program product for controlling an on-demand hot water heater including providing a plurality of nodes for receiving hot water from an on-demand hot water heater in a hot water delivery system, receiving a demand with a node identifier for hot water at a node, determining a hot water temperature for the node from a centralized database, the database including a set of node identifiers with a corresponding set of preset hot water temperatures, and controlling a temperature of hot water flowing from the water heater based on the determined hot water temperature.