A room heater is operated on receiving an on-command from a thermostat when a detected temperature detected by a second room-temperature detector falls below a first reference temperature, and is stopped on receiving an off-command when the temperature detected by the second room-temperature detector is above a second reference temperature that is set higher than the first reference temperature or when the thermostat is manually operated to be switched off. A setting temperature for temperature control to be carried out when the on-command is received again is updated according to a difference between the set temperature and the temperature detected by the first room-temperature detector on receiving the off-command. When the off-command is received before passing a predetermined period of time after receiving the on-command, the updating of the set temperature is prohibited if the temperature detected by the first room-temperature detector is below a predetermined minimum lower reference temperature.

The present disclosure provides a method and a system for controlling a heat pump water heater. The method includes: receiving a turn-on instruction; detecting the current temperature of the water in the water tank and the ambient temperature; acquiring a turn-on temperature difference according to the set temperature of the heat pump water heater and the ambient temperature, and acquiring a turn-on threshold according to the turn-on temperature difference; determining whether the current temperature is less than the turn-on threshold; if no, maintaining the current state; and if yes, controlling to enable the heat pump system to heat the water in the water tank.

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.

The autonomous energy saving device (2) enabling the control of a water heater (1) connected to a power grid comprising a phase P, a neutral N and a protective conductor T operating on a permanent power supply or during rate periods using a switch or timer, said energy saving device (2) comprises inputs E1, E2, E3 and the outputs S1, S2, S3 and between inputs E1 and E2 and the outputs S1 and S2 at least one primary circuit board (7) comprising at least one electronic component (3, 4) and a control algorithm to remove or reduce the heating times of the water heater (1) without changing the technical characteristics of the water heater, and in order to adapt its operation to the needs of the user.

A method for controlling a water heater is provided. The method includes: controlling operation of a blower when a first condition is satisfied; and controlling an air outlet to be partially or fully opened according to a first parameter or a first instruction. Furthermore, a device for controlling a water heater is provided, including a processor and a memory having program instructions stored thereon. When the program instructions are executed, the processor performs the method for controlling the water heater. Moreover, the water heater is provided, including a housing, a blower, an air-out channel, a heating part, and the device for controlling the water 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.

This invention provides an electronic control for combination (fuel-fired boiler and electric heat pump) building space and water heating systems that optimizes operation of such within the operating temperature limits and heat capability of both the heat pump and boiler unit in the combination system. In a diagnostic mode, the controller assesses the ability of existing heat radiation systems in thermostatically controlled zones to meet heating loads at different operating temperature limits of the heat pump and boiler. The system/controller provides information to guide most effective deployment of system heat-dissipation devices. In its normal operating mode, the controller is capable of receiving input signals from zone thermostats, the boiler and heat pump, along with current outdoor temperature and other data, processing and evaluating inputs over time, and outputting control signals. The controller facilitates use of a combined heat pump and boiler heating system with minimum equipment, installation, and operational cost.

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.

An apparatus and system for a combination space and water heater including a controller device and a method for control. The controller device is a self-contained system that can be added to, or in combination with, existing water heaters and hydronic air heating systems using standard plumbing connections, and provides a potable water system without any need of an intermediary heat exchanger. The controller device automatically monitors a heating capacity of the water heater and the hydronic heating coil over time, and correlates measured heating loads with one or more environmental temperatures, thermostats, user settings, and/or a supplemental heating system.

A heating and hot-water supply apparatus performs a heating operation by heating a heating medium with a heater and circulating the heating medium through a heating terminal, a hot-water supply operation by circulating the common heating medium through a hot-water supply heat exchanger, heating service water through heat exchange with the heating medium, and supplying hot water, and a simultaneous operation of the heating operation and the hot-water supply operation, and controls a distribution ratio of the heating medium between the heating terminal and the hot-water supply heat exchanger. The apparatus determines whether the heating terminal proceeding in the heating operation is a suspendible terminal to suspend the heating operation or an unsuspendible terminal not to suspend the heating operation in response to a request for the hot-water supply operation.