A tankless water heater system (100), with a heat exchanger device (20) comprising at least one hollow chamber (21, 22, 23, 24 ) and at least one electrical heating element (52, 53, 54), and: a controller device (30) with a temperature control unit (35), a tap event counter unit (32), a down-time counter unit (33) and a time delay unit (34); an electrical switching element (41, 42, 43) for connecting or disconnecting one or several heating elements (52, 53, 54) to/from a power supply; an outlet temperature sensor (27) linked with the temperature control unit (35); a flow rate sensor (29); wherein: the tap counter unit (32) is connected to the flow rate sensor (29) and is triggered when water flow rate exceeds a tap indication threshold {dot over (V)}.sub.0 the down-time counter unit (33) is triggered and retriggered by the tap counter unit (32) and both provide a down-time event signal after any inactivity period with no water flow and records the duration of inactivity; the time delay unit (34) is connected to and triggered by the tap counter unit (32) starting a delay period t.sub.OFF which duration is switched from a short default delay period to a long delay period by the down-time signal provided by the down-time counter unit (33); and the switching elements (41, 42, 53) are triggered by the time delay unit (34) only after the delay period has elapsed.

A safety system and method to prevent water within a top portion of a tank of an electric water heater to drop below a safe temperature during a load shedding period, other than a full emergency grid failure, by a power provider whereby to prevent the propagation of harmful bacteria in a top portion the tank. A control device monitors the water temperature in the top portion of the tank by the use of a temperature sensor. If the control device detects a temperature of the water in the top portion of the tank inferior to 140 degrees F., it will by-pass the instructions of the power provider and connect power to one or more of the resistive heating elements of the tank until a predetermined temperature above 140 degrees F. is attained before switching off the resistive heating elements.

An instant electrode water is provided. The instant electrode water heater comprises a housing for containing water therein with the housing having a water inlet and a water outlet. A plurality of electrode plates is disposed inside the housing. The electrode plates are placed such that the electrode plates are oriented parallel to each other and have a predetermined distance between two successive electrode plates for directing water received at the water inlet through successive channels, with each channel being formed by two successive electrode plates, to the water outlet. A plurality of electric contacts is disposed in the housing such that each electric contact is in a touching relationship with a respective electrode plate for providing AC electric power thereto. Electric control circuitry is connected to the electric contacts for controllably providing electric power thereto. The electrode plates may be contained in an electrode cartridge which is removably disposed in a cavity of the housing. The electric control circuitry may comprise current sense circuitry for providing a current sense signal indicative of an electric power usage of the electrodes. A microcontroller is connected to the current sense circuitry, an AC electric power supply, and a user interface. The microcontroller determines supply of the AC electric power to the electrodes in dependence upon the current sense signal and the user input signal and provides a supply control signal indicative of the supply of the AC electric power to the electrodes to the AC electric power supply.

An electric water heater tank adapted for connection to a controller, the tank including one or more electrical heating elements temperature sensing means mounted on the exterior of the tank wall and adapted to obtain a measurement of the temperature of the water in the tank, the temperature sensing means and each heating element being connected to an externally accessible connection means. The tank can include one or more heating element control means each connected to a corresponding one of the heating elements. The element control means can be connected to the externally accessible connection means.

A tankless water heater for use in a recreational vehicle uses one or more water chambers, each with a heating element, through which cold water flows and is heated. The system is connected to the alternating current of the recreational vehicle and controls the water temperature by sending the current through one or more TRIACs that change the firing angle of the current in order to increase or decrease power flow to the heating elements depending on the sensed temperature of the outflowing water that is compared against the selected temperature or to match the amount of power flow desired to be sent to the heating elements. The user selects whether to control the unit via a temperature selection or an amount of power flow selection.

A continuous-flow heater for heating a liquid includes a fluid-accessible channel arrangement with at least one heating channel configured for heating the liquid with at least one electric heating element arranged therein, an electronic control system configured to control electronic circuit breakers in order to electrically operate the heating element and to control the heat output of the heating element, a flow measuring device electrically connected to the electronic control system and configured to detect the volume flow rate of the liquid flowing through the channel arrangement and to provide a pulsed measurement signal, and a safety circuit connected on the input side to the flow measuring device and on the output side to the electronic control system in order to provide a supply voltage for controlling the electronic circuit breakers depending on whether the volume flow rate is greater than a minimum volume flow rate specification.

A liquid heating appliance for making a beverage, the liquid heating appliance comprising: a plurality of heating components for heating a liquid, where at least a first of the plurality of heating components is powered using mains power, a power management system, wherein the power management system comprises: a controller, and an energy storage device, wherein the controller is arranged to control an amount of the mains power applied to the first of the plurality of heating components, and further arranged to control an amount of stored power from the energy storage device to be applied to at least a second of the plurality of heating components.

A variable power water heater is disclosed. In embodiments, the variable power water heater includes a water tank, a heating element, a power supply circuit, a switch, and a controller. The heating element may be disposed within or coupled to the water tank. The power supply circuit may be configured to generate a power signal for the heating element. The switch may be configured to couple the power supply circuit to the heating element, and the controller may be configured to toggle the switch according to a pulse width modulation (PWM) scheme to control a duty cycle of the power signal transmitted from the power supply circuit to the heating element.

A water tank management system that connects either to a hot water tank directly or to an electric panel connected to the tank. The system comprises at least two temperature sensors, each of which is attached on the surface of the hot water tank near respective heating elements. The system comprises a control box which includes a solid-state relay that modulates the flow of electrical power to the heating elements in order to lower the energy used by the tank. The modulation is controlled by a program stored in a memory in the control box or communicated to the control box via an external controller. The system optionally comprises a third temperature sensor placed outdoors to measure the ambient outdoor temperature. With this feature, the system can activate a program to reduce energy consumption when the outdoor ambient temperature is outside a critical temperature range.

A tankless water heater includes a heater assembly, a temperature sensor, a flow sensor, a first heating element, a second heating element, and a controller. The heater assembly includes a water inlet, a water outlet, and a heating chamber defining a water flow path between the water inlet and the water outlet. The temperature sensor measures the temperature of water flowing through the heating chamber. The flow sensor measures a flow condition of water within the heating chamber. The first and second heating elements are located in the heating chamber and include first and second wattages, respectively. The second wattage is different from the first wattage. The controller is coupled to the first and second heating elements and the temperature and flow sensors. The controller is configured to regulate the amount of electrical current flowing through the first and second heating elements in response to the flow condition.