A method for controlling a water heater comprising: receiving report information transmitted by a user-wearable device at a predetermined frequency; determining whether a user is coming back according to user location information included in the report information; and if the user is coming back, turning on a return water pump to permit water outputted from a water outlet of the water heater to return to the water heater through a water return port. The present disclosure determines a movement direction and the user location by using report information transmitted by the user-wearable device. If the user is coming back, the return water pump is turned on to permit water to return, so that the user can take a hot bath immediately after arriving home, thereby improving user's experience.

A fluid sensor system detects one or more performance characteristics of a heating system that heats a fluid. The sensor system includes a probe having a finite length a portion of which is to be immersed in the fluid. The probe includes a resistive heating element and a fluid temperature sensor for measuring one or more performance characteristics, wherein the fluid temperature sensor is configured to measure a fluid temperature, and the resistive heating element is operable as a heater to create a temperature differential between the fluid and air to detect the fluid, and as a sensor to measure a fluid level.

An indicator generating method for generating an indicator which is suitable for maintenance prediction of a water heating system is proposed. A power state indication device generates a high power consumption signal if a heating device of the water heating system is activated. The time duration of the activation is such an indicator, if no water flow is present. Furthermore, the time interval between subsequent activations is such an indicator. A predictive maintenance method processes these condition-based indicators and determines a remaining useful lifetime according to a predictive maintenance model. The predictive maintenance device outputs a maintenance signal indicating required maintenance, if the remaining useful lifetime drops below a predetermined threshold. The methods may be performed by water heating systems or beverage makers.

A water supply system includes a main water tank that is configured to store water and includes a heater to heat the stored water to close to but below a boiling temperature thereof, to provide main heated water. A dispenser water tank receives a portion of the main heated water, and is free of any heating elements to add heat to the water stored therein, and providing dispensable heated water. A water mixer includes a first pipe for receiving the dispensable heated water from the dispenser tank and a second pipe for receiving utility water from a faucet that supplies utility-provided water, with a mixing chamber from which the waters from the first pipe and the second pipe are dispensed and/or in which these waters are admixed.

In a method for operating a heating device, fluid is initially introduced into a fluid chamber, then the heating elements of the heating device are switched on and a leakage current is detected as a temperature-dependent current flow through a dielectric insulation layer. A supply voltage of the heating devices is measured and is taken into account in an evaluation of the temperature at the fluid chamber as a function of the leakage current. The leakage current is converted into a leakage voltage by means of a resistor, which is then divided by the measured supply voltage. Subsequently, the quotient obtained may be multiplied by a compensation value in order to obtain a normalized leakage signal, which is normalized to a base value of the supply voltage. The normalized leakage signal is used, if a particular absolute value of the leakage signal is exceeded or if a particular slope of the profile of the leakage signal is exceeded, in order to top up the fluid chamber with more fluid and/or to reduce the heating power of at least one heating element.

The present disclosure discloses a dynamic equivalent circuit of a combined heat and power system, and a working method thereof. Controlled sources are used to represent a thermoelectric coupling source; equivalent inductance is used to represent a delay of a heat transmission pipeline; equivalent resistance is used to represent a heat load and a heat loss of the heat transmission pipeline; and equivalent capacitance is used to represent a heat storage water tank. A circuit model is used to uniformly represent two thermoelectric heterogeneous energy sources, and a single power simulation tool may be used to simulate a combined heat and power system, so that the simulation system has a simple structure and is easy to develop and maintain.

A water heater and methods of operating the water heater are provided. The water heater appliance includes a tank, a cold water inlet conduit extending into the tank, a heating element within the tank, a hot water conduit extending from the tank to a mixing valve, a mixed water conduit downstream of the mixing valve, and a user interface. The method includes and/or the water heater is operable for receiving, from the user interface, a user value for a tank temperature setpoint. An upstream water heater is detected and a capacity thereof is predicted. The tank temperature setpoint is then adjusted based on the predicted capacity of the upstream water heater.

A portable heating and cooling container for keeping retained liquids heated or cooled in the same compartment. An insulated vessel with a foam or vacuum insulating layer keeps the retained liquids at a consistent temperature for long periods of time. A heating component is attachable to an outside of an insulated vessel. The heating element is not used when the retained liquids are desired to be cool or cold. The heating component may penetrate either a double sidewall of the vessel housing or the vessel lid. A resistance heating element is retained within the insulated vessel to heat the retained liquid on demand as desired allowing for access to heated liquids remotely.

Control of temperature of water delivered by a dual-stage water heater having an external boiler with a first heater as first stage and an internal duct (water booster) with a second heater as second stage. A control loop based on a measured water temperature in the boiler and controls the first heater. A second loop calculate a reference booster water temperature based on the temperature error at the outlet (difference between a measured outlet water temperature and a reference outlet water temperature) and controls second heater based on error between reference booster water temperature and measured booster water temperature. The reference outlet water temperature depends on type of beverage (e.g. espresso, cappuccino) and includes a temperature profile with different temperature for different sub-beverages (e.g. coffee, milk). Takes into account physical response times, inertia of heater and anticipate sudden changes of reference water temperature at hot water outlet.

The disclosure includes a hot water circulation device, and a hot water device monitoring system including a circulation passage; a circulation pump circulating hot water in the circulation passage; a closed expansion tank in which a water chamber communicating with the circulation passage and an air chamber filled with a predetermined pressure in initial state are partitioned by a diaphragm; and a control unit controlling hot water circulation. The hot water circulation device includes an air chamber pressure sensor detecting pressure in the air chamber; a closing valve cutting off water chamber from the circulation passage; and an open valve opening to atmosphere from between closing valve and water chamber. The control unit closes closing valve and opens opening valve during hot water circulation, detects pressure in the air chamber by the air chamber pressure sensor, and issues a warning notification when the pressure is not within predetermined pressure range.