A water heating system including a tank to store water, a temperature sensor positioned to detect a temperature of the water, and a temperature control element configured to alter the temperature of the water. The system also includes a controller configured to control the temperature of the water based on a first temperature threshold during a first time period and monitor the amount of time that the temperature control element is in either the activated state or the deactivated state during the first time period. The control then determines a second temperature threshold for a subsequent time period based on the monitored amount of time.