Patent ID: 7603204

Claim:
A system for controlling a temperature of a liquid residing within a tank, comprising: a temperature sensor configured to detect the temperature of the liquid; a temperature control element configured to alter the temperature of the liquid, the temperature control element having at least an activated state and a deactivated state, wherein heat is applied to the liquid when the temperature control element is in the activated state; a clock; and logic configured to maintain the temperature of the liquid at a first temperature threshold by adjusting the temperature control element between the activated state and the deactivated state during each of a first plurality of time periods, the logic further configured to monitor usage of the temperature control element by determining an amount of time that the temperature control element is in the activated state during each of the first plurality of time periods based on a time value indicated by the clock, and the logic further configured to maintain the temperature of the liquid at a second temperature threshold by adjusting the temperature control element between the activated state and the deactivated state during a subsequent time period corresponding to one of the first plurality of time periods, wherein the second temperature threshold is automatically selected based on the amount of time that the temperature control element was determined to be in the activated state during the one of the first plurality of time periods corresponding to the subsequent time period.