Patent ID: 8111980

Claim:
A water heater comprising: a tank; an inlet that adds cold water to the tank; an outlet that withdraws heated water from the tank; a temperature sensor operable to sense a temperature related to a water temperature; a combustion chamber having a thermal relation to the tank; a gas heating element disposed in the combustion chamber; a valve connectable to a gas source and connected to the gas heating element; and a controller in communication with the valve and the temperature sensor, the controller being operable to selectively generate a control signal based on the sensed temperature, the selectively generated control signal controlling the valve to provide fuel to the heating element in bursts, each burst followed by a period during which gas is not supplied to the heating element, the controller being further operable to approach a water temperature setpoint with a plurality of bursts, wherein the gas heating element comprises a first combustive section and a second combustive section and wherein the water heater further comprises one or more gas manifolds comprising a first passageway to deliver fuel to the first combustive section and a second passageway to deliver fuel to the second combustive section, wherein the first combustion section and the second combustion section are independently controllable.