The Taco Hot-LinkPlus-e SmartPlug is designed to upgrade any domestic plumbing system. It adds intelligence to your system by learning when hot water is used in the home. The pipe-mounted temperature sensor records daily hot water usage patterns during the course of a week. Recorded data is used to automatically run the 006e3 at the same times the following week. So hot water is always available when it's needed. If your usage pattern changes, the SmartPlug adjusts automatically.