Patent ID: 7063132

Claim:
A water heater comprising: a tank having a wall defining an interior for holding water; and a heat exchange assembly positioned at least partially within said interior of said tank, said heat exchange assembly having a metallic outer tube positioned within said interior of said tank, said outer tube having a wall with an inner surface and end portions positioned within said interior of said tank; and a metallic inner tube extending within said outer tube and having end portions extending through said wall of said tank, said inner tube having a wall with an outer surface; wherein a portion of said outer surface of said inner tube contacts a portion of said inner surface of said outer tube, thereby facilitating the transfer of heat between said inner tube and said outer tube; and wherein an elongated passageway is defined between a portion of said outer surface of said inner tube and a portion of said inner surface of said outer tube, thereby facilitating the flow of fluid along a length of said outer tube and said inner tube.