Method and apparatus for preventing bacteria proliferation in an electric water heater

An electric water heater comprising a tank defined by a cylindrical side wall, a top wall and a dome-shaped bottom wall;

• a cold water inlet disposed for releasing cold water under pressure in a lower portion of said tank, two or more resistive heating elements to heat water in an upper and lower region of said tank, temperature sensing means for sensing water temperature in said upper and lower regions of said tank, control means to actuate at least one of said two or more resistive heating elements when said water temperature in at least one of said regions falls below a set point temperature value as sensed by said sensing means, said dome-shaped bottom wall defining a surrounding cavitated zone defined in said lower region of said tank between a lower end of said cylindrical side wall and said dome-shaped bottom wall, said surrounding cavitated zone defining a bacteria proliferation zone, convection means constituted by an inverted shallow cone shape baffle plate having an outer circular peripheral edge and a water passage means, said baffle plate being retained in said lower region of said tank and housing a substantial portion of a lower one of said resistive heating elements extending in said tank lower region, said resistive heating element being disposed in an upper chamber integrally formed along a top end section of said baffle plate and in communication with the space under said baffle plate spaced from said dome-shaped bottom wall, said upper chamber having an elongated slot opening for releasing hot water from under said baffle plate heated by said resistive heating element and causing heated water to flow about said outer circular peripheral edge and under the baffle plate and in the immediate area of said dome-shaped bottom wall and said surrounding bacteria proliferation zone at a temperature sufficient to kill and prevent bacteria proliferation, and a controller for controlling the duration of the heated water flow about said outer circular peripheral edge of said baffle plate sufficient to kill and prevent bacteria proliferation in said immediate area of said dome-shaped bottom wall.