Patent ID: 8286594

Claim:
A water heating apparatus, comprising: a combustion chamber; a burner assembly located within the combustion chamber; a variable flow premix low range blower assembly communicated with the burner assembly for supplying premixed fuel and air to the burner assembly, the low range blower assembly being operable over a low flow rate range extending from a low range low end to a low range high end; a variable flow premix high range blower assembly communicated with the burner assembly for supplying premixed fuel and air to the burner assembly, the high range blower assembly being operable over a high flow rate range extending from a high range low end to a high range high end, wherein the high range high end is greater than the low range high end; and a control system operably associated with the low range blower assembly and the high range blower assembly to selectively operate one or both of the blower assemblies as needed in response to heat demand on the water heating apparatus.