Abstract: An immediate hot-water supplying system 1 includes a P hot water supply device 10 configured to heat water flowing through a first supply pipe 2, an N hot water supply device 30 configured to heat water flowing through a second supply pipe 3, a check valve 6, and a coupled controller 60 configured to, when the flow amount detected by a second flow amount sensor 34 is equal to or more than a hot-water-supply detection flow amount, perform a hot-water supply operation in which a first burner 12 or a second burner 32 is burned with a circulation pump 16 stopped, and when the flow amount detected by the second flow amount sensor 34 is less than the hot-water-supply detection flow amount, perform a circulation heat keeping operation in which the first burner 12 is burned with the circulation pump 16 activated.

Abstract: A hot water supply apparatus has: a thermo-sensitive valve which is connected in parallel to a cold water delivery pipe and a hot water delivery pipe and which is closed when the hot water temperature to flow inside the valve is above a predetermined temperature to thereby shut off communication between the cold water delivery pipe and the hot water delivery pipe; and a circulation pump. By operation of the circulation pump, water circulation takes place from a heat exchanger through the hot water delivery pipe, a return pipe, the circulation pump, and a cold water supply pipe back to the heat exchanger. When the thermo-sensitive valve is open, water circulation takes place also through the thermo-sensitive valve. Instantaneous hot water supply operation is finished when an amount detected by a flow sensor falls below a predetermined amount during the instantaneous hot water supply operation.

Abstract: An immediate hot-water supplying system 1 includes a P hot water supply device 10 configured to heat water flowing through a first supply pipe 2, an N hot water supply device 30 configured to heat water flowing through a second supply pipe 3, a check valve 6, and a coupled controller 60 configured to, when the flow amount detected by a second flow amount sensor 34 is equal to or more than a hot-water-supply detection flow amount, perform a hot-water supply operation in which a first burner 12 or a second burner 32 is burned with a circulation pump 16 stopped, and when the flow amount detected by the second flow amount sensor 34 is less than the hot-water-supply detection flow amount, perform a circulation heat keeping operation in which the first burner 12 is burned with the circulation pump 16 activated.

Abstract: A hot water supply apparatus has: a thermo-sensitive valve which is connected in parallel to a cold water delivery pipe and a hot water delivery pipe and which is closed when the hot water temperature to flow inside the valve is above a predetermined temperature to thereby shut off communication between the cold water delivery pipe and the hot water delivery pipe; and a circulation pump. By operation of the circulation pump, water circulation takes place from a heat exchanger through the hot water delivery pipe, a return pipe, the circulation pump, and a cold water supply pipe back to the heat exchanger. When the thermo-sensitive valve is open, water circulation takes place also through the thermo-sensitive valve. Instantaneous hot water supply operation is finished when an amount detected by a flow sensor falls below a predetermined amount during the instantaneous hot water supply operation.