Abstract: 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.

Abstract: A hot water temperature sensing cut-off system and method for use with electric water heaters to preclude the flow of unsafe water from the water heater into the hot water distribution conduit to prevent the risk of bacteria transfer in the hot water distribution conduit. One simple solution is to mount a temperature responsive shut-off valve between the hot water supply outlet conduit of the tank of the water heater and the hot water distribution conduit and wherein the valve will shut-off water flow upon detection of an unsafe water temperature below 125 degrees Fahrenheit. Another solution is to use a controller to operate a shut-off valve. A temperature sensor is located to sense the water temperature at the intake of the hot water conduit and feeds a signal to the controller to operate a closure component of the valve to shut-off the hot water supply upon detecting a predetermined low water temperature fed to an inlet end of the control shut-off valve.

Abstract: An electric water heater is described and wherein the bottom portion of the water holding tank is provided with various forms of electric heating elements to heat the water in the lowermost region of the tank adjacent the dome-shaped bottom wall to a temperature sufficient to prevent the proliferation of bacteria growth such as the Legionella bacteria in such lowermost region. The insulating foam support base of the water heater also provides a thermal barrier to the heating elements while biasing the heating element on the dome-shaped bottom wall in a region to insure excellent heat transfer to the cavitated zone surrounding the dome-shaped bottom wall where sedimentary deposits occur to create a culture medium for bacteria growth.

Abstract: An electric water heater is described and wherein the bottom portion of the water holding tank is provided with various forms of electric heating elements to heat the water in the lowermost region of the tank adjacent the dome-shaped bottom wall to a temperature sufficient to prevent the proliferation of bacteria growth such as the Legionella bacteria in such lowermost region. The insulating foam support base of the water heater also provides a thermal barrier to the heating elements while biasing the heating element on the dome-shaped bottom wall in a region to insure excellent heat transfer to the cavitated zone surrounding the dome-shaped bottom wall where sedimentary deposits occur to create a culture medium for bacteria growth.

Abstract: An electric water heater is described and wherein a bottom resistive heating element extends in at least a portion of the cavitated circumferential area defined inside the tank between the tank side wall and the dome-shaped bottom wall and wherein deposits accumulate to create a culture medium for bacteria growth. The bottom resistive heating element heats water in this cavitated area to a temperature sufficient to sanitize a lower region of said water holding tank and to kill bacteria such as the Legionella bacteria.

Abstract: 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.

Abstract: A water holding tank for electric water heaters is described and particularly an improvement to the bottom end construction of the tank to prevent bacteria proliferation and the elimination of the cavitated circumferential area where sediments deposit to form a culture bed for bacteria to proliferate. Instead of modifying the shape of the bottom wall the improvement is a simple solution in that a filler material is set in at least a lowermost portion, and preferably a major portion, of the cavitated circumferential area to isolate that area from the interior of the water holding tank and form smooth flat surface areas which are planar to cause sediments to disperse and not form beds for bacteria to proliferate.

Abstract: An electric water heater is described and wherein the bottom portion of the water holding tank is provided with various forms of electric heating elements to heat the water in the lowermost region of the tank adjacent the dome-shaped bottom wall to a temperature sufficient to prevent the proliferation of bacteria growth such as the Legionella bacteria in such lowermost region. The insulating foam support base of the water heater also provides a thermal barrier to the heating elements while biasing the heating element on the dome-shaped bottom wall in a region to insure excellent heat transfer to the cavitated zone surrounding the dome-shaped bottom wall where sedimentary deposits occur to create a culture medium for bacteria growth. In one embodiment a heating wire transfers heat to the lowermost region from the lower end of the surrounding side wall of the tank and access to the heating wire is provided for connection and removal thereof.

Abstract: A method and an apparatus is described for preventing bacteria proliferation in a bottom end of a water holding tank of an electric water heater. Different water convection devices are described for convecting heated water from inside the tank and into the bottom end of the tank to raise the temperature at the bottom end sufficiently high to prevent bacteria growth and particularly at a temperature of at least 46 degrees C. where the Legionella bacteria can not survive. The temperature at the bottom end of the tank is monitored and the convection devices controlled to maintain the desired hot water temperature. An added benefit of the invention is that it also prevents sediment deposits and water temperature stratification in the tank bottom end section.

Abstract: A method and an apparatus is described for preventing bacteria proliferation in a bottom end of a water holding tank of an electric water heater. Different water convection devices are described for convecting heated water from inside the tank and into the bottom end of the tank to raise the temperature at the bottom end sufficiently high to prevent bacteria growth and particularly at a temperature of at least 46 degrees C. where the Legionella bacteria can not survive. The temperature at the bottom end of the tank is monitored and the convection devices controlled to maintain the desired hot water temperature. An added benefit of the invention is that it also prevents sediment deposits and water temperature stratification in the tank bottom end section.

Abstract: A method and an apparatus is described for preventing bacteria proliferation in a bottom end of a water holding tank of an electric water heater. Different water convection devices are described for convecting heated water from inside the tank and into the bottom end of the tank to raise the temperature at the bottom end sufficiently high to prevent bacteria growth and particularly at a temperature of at least 46 degrees C. where the Legionella bacteria can not survive. The temperature at the bottom end of the tank is monitored and the convection devices controlled to maintain the desired hot water temperature. An added benefit of the invention is that it also prevents sediment deposits and water temperature stratification in the tank bottom end section.

Abstract: An electrical water heater adapted for energy management and a method of controlling the consumption of electrical power from the power supply grid of a utility is described. The bottom resistive heating element of the water heater is a dual element resistive heating element which has a high power rated resistive heating element to heat water and a further low power rated resistive heating element. The power rating of the low power resistive heating element is calculated to be lower than the supply grid diversified mean load. A controller has a communication link with a utility which manages the power supply grid. The utility can control the resistive heating elements of the dual element in such a way, and depending on conditions of the grid, to conserve energy and regulate its frequency thereby resulting in a cost saving to the consumer and the utility. The low power rated resistive heating element is also connectable to an alternative power source.

Abstract: A dielectrically insulated secondary tubular flue for mounting inside a water holding tank of a gas-fired water heater is provided to increase the efficiency of the water heater. The secondary tubular flue has opposed tubular end sections and an helical tubular section integrally formed therewith. The tubular end sections each have connecting end sections adapted to form a part of a dielectric connector for securing the secondary tubular flue inside of the water holding tank by the dielectric connectors.

Abstract: A water holding tank for electric water heaters is described and particularly an improvement to the bottom end construction of the tank to prevent bacteria proliferation and the elimination of the cavitated circumferential area where sediments deposit to form a culture bed for bacteria to proliferate. Instead of modifying the shape of the bottom wall the improvement is a simple solution in that a filler material is set in at least a lowermost portion, and preferably a major portion, of the cavitated circumferential area to isolate that area from the interior of the water holding tank and form smooth flat surface areas which are planar to cause sediments to disperse and not form beds for bacteria to proliferate.

Abstract: An electric water heater is described and wherein the bottom portion of the water holding tank is provided with various forms of electric heating elements to heat the water in the lowermost region of the tank adjacent the dome-shaped bottom wall to a temperature sufficient to prevent the proliferation of bacteria growth such as the Legionella bacteria in such lowermost region. The insulating foam support base of the water heater also provides a thermal barrier to the heating elements while biasing the heating element on the dome-shaped bottom wall in a region to insure excellent heat transfer to the cavitated zone surrounding the dome-shaped bottom wall where sedimentary deposits occur to create a culture medium for bacteria growth. In one embodiment a heating wire transfers heat to the lowermost region from the lower end of the surrounding side wall of the tank and access to the heating wire is provided for connection and removal thereof.

Abstract: An electrical water heater adapted for energy management and a method of controlling the consumption of electrical power from the power supply grid of a utility is described. The bottom resistive heating element of the water heater is a dual element resistive heating element which has a high power rated resistive heating element to heat water and a further low power rated resistive heating element. The power rating of the low power resistive heating element is calculated to be lower than the supply grid diversified mean load. A controller has a communication link with a utility which manages the power supply grid. The utility can control the resistive heating elements of the dual element in such a way, and depending on conditions of the grid, to conserve energy and regulate its frequency thereby resulting in a cost saving to the consumer and the utility. The low power rated resistive heating element is also connectable to an alternative power source.

Abstract: A hot water pulsating alarm system and method for electric or gas-fired water heaters is described. A sensor senses the water temperature in an upper region of the water tank of the water heater and feeds temperature signals to a controller. The controller operates an electromechanical valve connected to the pressurized cold water supply line of the water tank. Upon detecting a low temperature value stored in the memory of the controller, the controller causes a shut-off electro-mechanical valve to close and open in a predetermined sequence and during a predetermined time period. This causes interruptions of hot water being drawn from the upper region of the water tank to feed a hot water supply conduit and creating a pulsating water temperature change in hot water being discharged through fixtures connected to the hot water supply conduit.

Abstract: A hot water pulsating alarm system and method for electric or gas-fired water heaters is described. A sensor senses the water temperature in an upper region of the water tank of the water heater and feeds temperature signals to a controller. The controller operates an electromechanical valve connected to the pressurized cold water supply line of the water tank. Upon detecting a low temperature value stored in the memory of the controller, the controller causes a shut-off electro-mechanical valve to close and open in a predetermined sequence and during a predetermined time period. This causes interruptions of hot water being drawn from the upper region of the water tank to feed a hot water supply conduit and creating a pulsating water temperature change in hot water being discharged through fixtures connected to the hot water supply conduit.

Abstract: A method and an apparatus is described for preventing bacteria proliferation in a bottom end of a water holding tank of an electric water heater. Different water convection devices are described for convecting heated water from inside the tank and into the bottom end of the tank to raise the temperature at the bottom end sufficiently high to prevent bacteria growth and particularly at a temperature of at least 46 degrees C. where the Legionella bacteria can not survive. The temperature at the bottom end of the tank is monitored and the convection devices controlled to maintain the desired hot water temperature. An added benefit of the invention is that it also prevents sediment deposits and water temperature stratification in the tank bottom end section.

Abstract: A high efficiency condensing flue gas-fired water heater is provided with a secondary tubular flue mounted inside the water tank and secured thereto by dielectric connectors to electrically isolate the secondary tubular flue from the tank. The secondary tubular flue has an intermediate helical section and opposed connecting end sections which each form a part of the dielectric connectors. The connectors do not require any welding for its installation to the tank and a compression nut and dielectric insulators provide for a leak proof and electrically isolated connection. The method of securing the secondary tubular flue is also described.