In one aspect, a first device includes a processor and storage accessible to the processor. The storage bears instructions executable by the processor to receive input from a water heater meter that monitors a water heater and provide an output comprising information pertaining to a time estimate related to the provisioning of heated water based on the input.

A method and a device to heat water in an electrical boiler are disclosed. The method include the steps of storing user's requests of hot water in association with corresponding times of requests, heating water in advance to a next user's request, wherein the next user's request is estimated on the stored user's requests. The device is the hardware implementing the method.

A temperature control unit includes a fitting, a heating wire, a first temperature sensor, and a housing, which contains the first temperature sensor and portions of the fitting and the heating wire. The fitting includes a fluid inlet, a fluid outlet, a flow channel extending from the fluid inlet to the fluid outlet, and a passage extending through a wall of the fitting to the flow channel. The heating wire extends through the passage and into the flow channel. The first temperature sensor is secured to an external surface of the fitting opposite the flow channel and is electrically connected to the heating wire.

An apparatus includes a high-pressure tank, a controller, a valve, controlled by the controller, and a heater.

Systems and methods for integrating photovoltaic (PV) energy into water heater systems are disclosed. The disclosed technology includes determining whether a current water temperature is less than a first PV heat point that is greater than a normal heat point, and if so, outputting instructions for PV energy to be transferred from a PV system to a heating device of the water heater. If the current water temperature falls below a second PV heat point that is less than the normal heat point, the disclosed technology includes outputting instructions for energy to be transferred from a utility system to the heating device.

A smart circulation control instantaneous-heating storage heat exchanger includes a heat exchanger, a cold-water pipe, a hot-water pipe, an internal circulation pipe, and a control unit. The heat exchanger includes a storage space. The internal circulation pipe includes a two-way valve and a circulation pump. The control unit is connected to the two-way valve and the circulation pump. The internal circulation pipe functions to return a part of heated water back to the storage space to enhance thermal conversion efficiency and save energy and improve controllability. Positions for supplying cold water and returning water are made at different sites, and the circulation pump and the internal circulation pipe are used to selectively execute functions of anti-freezing, pre-heating, and heat balancing. An external circulation pipe is additionally included such that by means of the two-way valve and the circulation pump, switching can be made between internal and external circulations.

A tankless water heater, comprising: a flow channel with a cold-water inlet pipe, a heating unit with an heating element configured to heat water flowing through the heating unit and a hot-water outlet pipe, and a control unit configured to control the tankless water heater, wherein the control unit is configured to receive a power limitation signal of an external facility management system and to control a heating output of the heating element depending on the power limitation signal.

A water heater system includes a water heater having a first water outlet and a second water outlet. The water heater system further includes a flow detection device coupled to the first water outlet to detect a water flow through the first water outlet. The water heater system also includes a flow control valve fluidly coupled to the second water outlet. The flow control valve is configured to control a flow of water through the second water outlet based on whether the water flow through the first water outlet is detected by the flow detection device.

A heat pump may include a compressor configured to compress a refrigerant, a first temperature sensor configured to detect an outdoor temperature, a second temperature sensor provided in heating pipes connected to a heating device, and a controller. Based on a first sensing value of the first temperature sensor, the controller may be configured to control a compressor, control power to a boiler, and/or calculate an expected efficiency of the heat pump. Based on the expected efficiency and/or a second sensing value of a second temperature sensor, the controller may be configured to control power to the boiler.

The present invention improves the user-friendliness of a hot-water supply apparatus when using hot water supply and air conditioning. A switching control unit 27, which switches between heat medium flow paths 4 and 5 according to an air conditioning ready state or a hot-water supply ready state, switches a heat medium flow path to the hot-water supply ready state by a switching valve 21 in the case where air conditioning is not used by the time an air conditioning standby time elapses during standby in the air conditioning ready state.