Patent ID: 7299768

Claim:
A gas-fired water heating apparatus comprising an upright cylindrical thermally insulated storage tank, an axially extending exhaust gas pipe passing centrally through the storage tank, said exhaust gas pipe being provided with an inlet for admitting exhaust gas at a free end thereof, a combustion chamber arranged under the storage tank, and an atmospheric gas burner arranged within the combustion chamber, said atmospheric gas burner having a complete premixing fuel gas/air supply system; in which the exhaust gas pipe has a pipe section extending within the combustion chamber and the pipe section of the exhaust gas pipe within the combustion chamber extends deeply into the combustion chamber until said free end is in the vicinity of a bottom of the combustion chamber, and in which the pipe section of the exhaust gas pipe within the combustion chamber is arranged eccentrically to a remaining portion of the exhaust gas pipe that passes centrally through the storage tank.