Disclosed herein is a water heating system including a water heater having a tank, and a first temperature sensor disposed toward a top end of the tank to measure a first temperature and a second temperature sensor disposed toward a bottom end of the tank to measure a second temperature. The water heating system can further include a controller communicably coupled to the first temperature sensor and the second temperature sensor, where the controller determines an amount of heated water in the tank based on one or more algorithms and measurements made by the first and second temperature sensors.

When a heating operation mode using a heating unit is specified and when a hot water supply request using the hot water in a hot water storage tank does not occur, an air conditioning apparatus transmits a first selection signal for selecting the heating unit to a three-way valve. When the heating operation mode is specified and when the hot water supply request occurs, the air conditioning apparatus transmits, to the three-way valve, a second selection signal for changing a destination of circulation of secondary refrigerant from the heating unit to a coil heat exchanger, and transmits an operation start signal to a refrigerant indoor unit.

A pump device is proposed for arrangement on a recirculation line of an industrial water system including a feed pump, a check valve and a bypass line for the check valve. The bypass line is arranged in parallel to the check valve and wherein a combination of the check valve and bypass line is arranged in series to the feed pump.

A fluid heating system including a fluid supply subsystem having a fluid heating device, a fluid output subsystem, and an intermediary fluid device. The fluid heating system also includes a control device for the fluid supply subsystem, a first temperature sensor, a second temperature sensor, and a control circuit coupled to the control device. The control device is configured to control one selected from a group consisting of the fluid heating device and an amount of water input to the intermediary fluid device. The first and second temperature sensors are configured to output first and second temperature signals, respectively. The control circuit is configured to generate a first control signal based on the second temperature signal, determine a multiplier, generate a second control signal based on the first temperature signal, and send a main control signal to the control device based on the first and second control signals.

A digital fluid heating system may include a solar collection system configured for focusing sunlight on a focal axis, an elongated flow element arranged and configured for transporting fluid along the solar collection system at the focal axis, and a flow-control assembly comprising a digitally controlled valve configured to control the flow of the fluid in the elongated flow element such that pathogens present in the fluid are substantially inactivated before the fluid exits the fluid heating system and at a maximized flow rate under the given energy providing conditions. The system may also include one or more digital controls and communication systems for remote and/or automatic control.

A hot water supply device includes a heater, a water channel, a mixing valve unit, and a circulation mechanism. The mixing valve unit has a valve member and a drive unit configured to drive the valve member to change a mixing ratio of supply water heated by the heater and unheated water. The circulation mechanism has: a connection passage that connects the water channel to the heater by being branched from a part of the water channel between the mixing valve unit and the heater; an on-off valve that opens and closes the connection passage; and a pump configured to return the supply water remaining in the water channel through the connection passage to the heater. A drive amount acquisition unit acquires a drive amount of the drive unit, and a controller controls the circulation mechanism based on the drive amount acquired by the drive amount acquisition unit.

A water preconditioner system comprising a user interface for manually or automatically receiving inputs from a user, a mixing assembly including a plurality of control valves coupled to hot and cold water supply lines, and a controller in communication with the plurality of control valves and the user interface for controlling the operation of the system. The controller is configured to operate in a plurality of modes to precondition the water to one of a desired preset water dispensing temperature or a target temperature different from the desired preset water dispensing temperature.

The disclosed technology includes an on-demand water heater which uses an electric heat source to heat the water. The on-demand water heater can have a low fluid capacity heating chamber which has an inlet and an outlet, an electric heat source for heating the water, and a controller to control the electric heat source and maintain the temperature of the water at a predetermined temperature setting. The on-demand water heater can be powered by a direct current power source. The on-demand water heater can also utilize a solar thermal system to provide additional heat to the water.

A hydronic system, of the present disclosure, includes a control unit including a memory comprising stored instructions and a processor configured to execute the stored instructions to cause the control unit to perform at least monitoring, a volume of hot water in a hot storage tank via a first set of flowmeters, monitoring, a volume of chilled water in a cold storage tank via a second set of flowmeters, monitoring, a first outlet temperature of the hot water within the hot storage tank via a first temperature sensor and a second outlet temperature of the chilled water within the cold storage tank via a second temperature sensor, and operating, a heat pump unit for recharging the hot water and the chilled water within the hot storage tank and the cold storage tank respectively. The heat pump unit is operated when a respective predetermined limit reaches for anyone of identified parameters.

A hot water circulation system comprises a water heater having a cold-water inlet and a hot water outlet. A water pump circulates water through the water heater to produce hot water. The hot water is circulated to a thermal bypass valve, which is configured to close when hot water contacts a heat activated seal. A bypass circuit is coupled between the hot water outlet and the cold water inlet of the water heater. The bypass circuit prevents hot water from circulating from the hot water outlet to the cold-water inlet when the thermal bypass valve is open and promotes circulating hot water from the hot water outlet to the cold water inlet when the thermal bypass valve is closed. Upon a temperature sensor sensing hot water entering the cold-water inlet, the water heater turns of the water pump.