A storage electric water heater includes a tank, an inlet tube, an outlet tube, an isolating member, and a heating device, wherein the tank has a storing space. The inlet tube and the outlet tube are disposed in the tank. The isolating member is disposed in the storing space to divide the storing space into a first chamber and a second chamber. The first chamber communicates with the inlet tube and the outlet tube. The heating device is disposed in the second chamber and includes a tube body and a heating element. Two ends of the tube body communicate with the first chamber, so that water in the first chamber could enter an interior of the tube body. The heating element is disposed on a tube wall of the tube body. Thermal energy generated by the heating element could be transferred to the interior of the tube body via the tube wall to heat up water in the tube body, thereby facilitating the thermal convection of water in the first chamber.

A multi-functional retrofit cover plate assembly and method for an electric water heater to provide interconnection with an alternative energy system to heat water in a water holding tank of the electric water heater. The cover plate is adapted for replacement connection over a bottom access opening formed in an outer casing of the electric water heater which permits access to a bottom resistive heating element and electrical connections. The retrofit cover plate is shaped to define an internal dedicated compartment. A dual resistive heating element is provided for replacement of the bottom resistive heating element. An electronic switch unit is further provided and it has a power cut-off switch for connection to an alternative supply voltage. A temperature sensor is provided for mounting against an outer surface of the tank of the water heater to feed actual temperature signals of water temperature within the tank, in a lower region thereof, to the electronic switch unit which operates the power cut-off switch upon a predetermined temperature having been attained in the tank of the water heater. The retrofit cover plate and the assembly also make it possible to covert the water heater to a high temperature water heater or to adapt the electric water heater to a thermal fluid heat source.

A water heating system is provided. The water heating system includes a tank having a wall, a water inlet defined through the wall and configured to allow ingress of water into the tank, and a water outlet defined through the wall and configured to allow egress of water from the tank. The water heating system also includes a first heating element disposed in a first portion of the tank. The first heating element has a substantially elongate shape and is inclined at a first predefined angle with respect to a base of the tank.

The disclosed technology includes systems and methods for operating a fluid heating device comprising a heat pump and an electric heating element. The disclosed technology can include a system and method that can receive current data from a current sensor and temperature data from a temperature sensor, determine whether the current is greater than or equal to a threshold current and whether the temperature is greater than or equal to a threshold temperature, and output a control signal to heat the fluid using the heat pump only or the electric heating element only based on the current data and the temperature data.

A fluid heating device comprising a heat pump and an electric heating element can include a system and method that can receive current data from a current sensor and temperature data from a temperature sensor, determine whether the current is greater than or equal to a threshold current and whether the temperature is greater than or equal to a threshold temperature, and output a control signal to heat the fluid using the heat pump only or the electric heating element only based on the current data and the temperature data.

An improved boiler apparatus having multiple resistive heating elements are provided with fixed resistances that can be rewired to allow dual voltage capability and at the same time, reduced watt density. For 120V operation, the large diameter 9-ohm coil is used alone to provide the lowest possible watt density. For 240V operation, all three heating coils are wired in series, creating a low watt density but high wattage heater.

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.

A system and method for controlling power to a water heater. The method comprises providing the water heater in a locked state, wherein at least one heating element of the water heater is inoperable when the water heater is in the locked state, coupling a digital key module to a communications port of the water heater, and receiving a digital key from the digital key module through the communications port. The method comprises coupling an electrical grid controller to the water heater through the communications port and placing the water heater in an unlocked state, wherein the at least one heating element of the water heater is operable when the water heater is in the unlocked state.

The present invention relates to a terminal device for connecting a heating apparatus with an electricity supply, in particular for a tubular heating apparatus for household appliances, wherein the heating apparatus includes at least one electric resistance heating element. The terminal device comprises a mounting and reception section arranged for being electrically connected with the electric resistance heating element of the heating apparatus, a connector section arranged for being electrically connected on its one end side with an electrical power supply and on its other end side with the mounting and reception section, and a thermal fuse unit for detecting an excess temperature of the heating apparatus, which is in heat transfer contact with at least the mounting and reception section and which is connected in the electric supply circuit for supplying the electric resistance heating element of the heating apparatus with electricity. Moreover, the mounting and reception section comprises a cavity for receiving at least the thermal fuse unit.

An electric water heater has upper and lower electric resistance type heating elements respectively controlled by a single pole, double throw upper thermostat and a single pole, single throw lower thermostat. The upper and lower thermostats are operatively interconnected by a wiring harness having outer conductor end portions that are connected to a terminal block portion of an external junction box to provide the water heater with a variety of heating element operating modes without having to replace either of the thermostats, vary the wiring harness interconnections therebetween, or vary the connection between the outer conductor end portions and the terminal block. The water heater may thus be advantageously manufactured in a single variant that may be easily and quickly modified in the field to selectively alter the heating element control mode of the water heater.