A water heater including a cold water intake, a hot water output, a fluid pathway arranged between the cold water intake and the hot water output and adapted to convey water flowing from the cold water intake to the hot water output. A heating element is adapted to heat water that is in the fluid pathway. A power electronics unit is coupled to the heating element. A controller is configured to regulate a temperature of the water in the fluid pathway to an adjustable hot water temperature by controlling the power electronics unit. A water draw-off detector is adapted to detect a water draw-off event and a water sensor is adapted to determine a reference parameter corresponding to a temperature of the water.