Games We Play: The New and The Old

Apparatus and method for controlling a hot water heater to heat water during off peak load hours to a desired temperature by the end of a predetermined period of time. The heating is in partial increments, the water being heated a partial amount in each of a plurality of predetermined time segments with a view to reaching the desired temperature at the end of the predetermined time period. The water is heated by adjusting the heater at each segment to its maximum power or a portion thereof. The method includes the steps of computing the heater power required for the next time segment, setting the heater power accordingly, waiting until the end of the time segment, determining the new temperature of the water, and repeating the steps until the end of the time period.