An electric water heater having a water holding tank defined by a cylindrical side wall, a top wall and a dome-shaped bottom wall. A cold water inlet is disposed for releasing water under pressure in a lower portion of the tank. Two or more resistive heating elements heat water in an upper and lower region of the tank. The lower portion of the cylindrical side wall and the outer circumferential portion of the dome-shape bottom wall form a circumferential cavitated area inside the tank in which sediments deposit forming a bed in which bacteria can proliferate. A conduit is secured about at least a substantial circumferential portion of an outer surface of the cylindrical side wall adjacent the cavitated area. A resistive heating wire is disposed in the conduit and has connection leads extending out of a free open end of the conduit to an access area to provide connection to power terminals and a control for controlling the supply of power to the resistive heating wire.