Patent ID: 6880493

Claim:
A method for operating a gas fired residential water heater having a water storage tank with a hot water outlet and a cold water inlet dip tube therein, the method comprising: detecting a first temperature of water in an upper portion of the tank; detecting a second temperature of water in a lower portion of the tank; applying heat to the tank to minimize stacking of water temperature in the tank in response to first, the first temperature at the water in the upper portion of the tank being below a set point temperature plus a fixed, upper temperature differential, and second, the second temperature of the water in the lower portion of the tank being less than a set point temperature minus a fixed, lower temperature differential; applying heat to the tank in response to first, the second temperature of the water in the lower portion of the tank being above the set point temperature minus the fixed, lower temperature differential, and second, the first temperature of the water in the upper portion of the tank being less than the set point temperature minus a fixed, upper temperature differential, to maintain water in the upper portion and lower portion of the tank at a desired temperature.