A joint connects to a hot water source, a toilet tank of a toilet, and a hot water outlet. A set of pipes connecting the hot water source and the joint may be referred to herein as “main hot water pipes.” Water exiting the hot water source into the main hot water pipes is above a desired water temperature. As time passes, however, water that rests in the main hot water pipes may fall below the desired water temperature. Rather than wasting all of the cooled water resting in the main hot water pipes in order to use hot water at the hot water outlet, at least a portion of the cooled water may be used to refill the toilet tank. Therefore less cooled water exits the hot water outlet before fresh water reaches the hot water outlet.

The invention solves the problem of hot water flow in a domestic hot water installation. The subject of the installation according to the invention is that on a third cold water branch (13) that feeds the heating device (1) a control switch (4) is installed, said switch (4) is connected by control system (11) with hot water flow forcing device (3) set on a second hot water circulation branch (2).

A joint connects to a hot water source, a toilet tank of a toilet, and a hot water outlet. A set of pipes connecting the hot water source and the joint may be referred to herein as “main hot water pipes.” Water exiting the hot water source into the main hot water pipes is above a desired water temperature. As time passes, however, water that rests in the main hot water pipes may fall below the desired water temperature. Rather than wasting all of the cooled water resting in the main hot water pipes in order to use hot water at the hot water outlet, at least a portion of the cooled water may be used to refill the toilet tank. Therefore less cooled water exits the hot water outlet before fresh water reaches the hot water outlet.

The present disclosure is directed to a hot water recirculation system with a return tee. The system includes a water heater, several supply lines, and a return tee. The hot water supply line is communicatively coupled to the water heater and at least one fixture and provides heated water from the water heater to the at least one fixture. The cold water supply line provides cold water from a cold water source to the water heater. Finally, the return line is communicatively coupled to the hot water supply line and delivers cooled water from the hot water supply line to the water heater. A return tee is communicatively coupled to the return line, the cold water supply line, and the water heater. This return tee provides cooled water from the return line and cold water from the cold water supply line to the water heater, which heats the water.

A domestic hot water supply system, comprising a water heater, a cold water pipe and a hot water pipe connected to the water heater respectively at one end, wherein the cold water pipe is connected to a water main at another end, and one or more water points are arranged in parallel between the cold water pipe and the hot water pipe, wherein a water pump is arranged between the water heater and the water point closest to the water heater on the hot water pipe, the water pump has a control module, the control module includes a signal receiver, a check valve is disposed at a farthest water point from the water heater between the cold water pipe and the hot water pipe, and a temperature sensor is disposed on the side of the check valve adjacent to the hot water pipe, the temperature sensor includes a signal transmitter.

Provided is a hot water distribution system comprising a water heater, a water pump, a controller, a temperature sensor, a point-of-use, and a diverting valve capable of directing water from the water heater to either the point-of-use or back to the water heater.

A hot water supply system according to the present invention includes: a hot water supply unit configured to supply hot water; an opening and closing valve configured to connect a hot water supply pipe, which is configured to supply hot water to a user from the hot water supply unit, and a cold water supply pipe, which is configured to supply cold water introduced from a cold water inflow pipe to the user, to allow water to flow or configured to disconnect the hot water supply pipe from the cold water supply pipe to block the water from flowing; a circulation pump configured to circulate water supplied from the hot water supply unit through the hot water supply pipe, the opening and closing valve, the cold water supply pipe, and the hot water supply unit; and a control unit configured to, when a water-preheating signal of the user is input, open the opening and closing valve, and operate the circulation pump to preheat water which is to be supplied to the user.

The invention relates to an economizer device having an expansion vessel provided with a pressure sensor Cp, a temperature sensor CT on a hot-water intake Ec, four valves, a non-return valve preventing the water from the cold-water intake EF from entering the expansion vessel, and an electronic board connected to the sensors and to the valves. The economizer device stores the cooled water coming from the hot-water intake in the expansion vessel until the water reaches a set temperature that is sufficient for supplying a point of use of a domestic installation using hot water. When the expansion vessel fills, the stored cooled water is preferably used as cold water to supply either the point of use with cold water or else another domestic installation provided to use cold water.

The present disclosure provides a computer-implemented method of predictively preparing a water provision system installed in a building, the water provision system comprising a heat pump configured to transfer thermal energy from outside the building to a thermal energy storage medium inside the building and a control module configured to control operation of the heat pump, the control module having executing thereon a first machine learning algorithm, MLA, having previously been trained to determine a correlation between cold water usage and a subsequent heated water demand, the water provision system being configured to provide water heated by the thermal energy storage medium to an occupant of the building at one or more water outlets, the method being performed by the control module and comprising: receiving first sensor data indicating cold water usage at a first water outlet; determining whether the cold water usage at the first water outlet is correlated to a subsequent heated water demand at a second water outlet by inputting the first sensor data to the first MLA; and upon determining that the cold water usage at the first water outlet is correlated to a subsequent heated water demand at a second water outlet, preparing the water provision system for delivering heated water.

The concepts relate to reducing energy loss associated with hot water systems. One example is manifest as a system with an automatic hot water recovery apparatus and selective hot water isolation devices. In one example a selective hot water isolation device is configured to be connected in fluid flowing relation with a first water line and a second water line and the selective hot water isolation device is configured to control water cross-over from the second water line into the first water line based upon water flow through the first water line.