The 3rd generation Nest Learning Thermostat is slimmer sleeker & even more beautiful. With a bigger sharper display & far sight you can see the time or the temperature you've set from across the room. & now it even controls your hot water tank. The Nest Thermostat learns the temperature you like then programs itself. It uses built-in sensors to confirm no one's home & It knows how long it takes to heat your home so you're comfortable when you get there. When you leave it turns itself down so you save energy. & you can check your Energy History with the Nest App to see how much you've saved.