A control system for an electric water heater having an upper heating
element and a lower heating element includes a control module that
controls operation of the electric water heater by selectively toggling
the upper and lower heating elements between an ON state and an OFF
state. The control module maintains a stratification of water within the
water heater including a first volume maintained at a set point
temperature and a second volume held at a setback temperature, which is
less than the set point temperature. The setback temperature is low
enough to maintain the stratification yet high enough to allow the upper
heating element to heat water from the second volume to the set point
temperature prior to exiting the water heater.