Abstract: Provided is an instantaneous hot water circulation unit with a scale cleaning function which can easily perform pipe cleaning for removing scale. The instantaneous hot water circulation unit which includes a hot water supply inlet portion connected to a hot water discharge unit of a hot water supply device, a hot water supply outlet portion connected to an external hot water supply unit, a hot water returning unit, a hot water outgoing unit, a hot water supply pipe, a hot water pipe, and a circulation pump, and a bypass pipe, which drives the circulation pump to perform an instantaneous hot water circulation operation when stoping hot water supply, wherein a storage tank configured to store a cleaning agent used in a cleaning operation of cleaning an inside of the pipe of the hot water supply device is provided at the bypass pipe.

Abstract: A water heating apparatus includes: a water heating circuit; a heater for heating the water heating circuit; and a controller for controlling the water heating apparatus. The water heating circuit includes a heat exchanger for heating a fluid including water and hot water, and a pipe for supplying the fluid via the heat exchanger. The controller is configured to drive the heater in a cleaning mode in which a cleaning liquid for cleaning an inside of the heat exchanger is supplied to the heat exchanger through the pipe.

Abstract: Provided is an instantaneous hot water circulation unit with a scale cleaning function which can easily perform pipe cleaning for removing scale. The instantaneous hot water circulation unit which includes a hot water supply inlet portion connected to a hot water discharge unit of a hot water supply device, a hot water supply outlet portion connected to an external hot water supply unit, a hot water returning unit, a hot water outgoing unit, a hot water supply pipe, a hot water pipe, and a circulation pump, and a bypass pipe, which drives the circulation pump to perform an instantaneous hot water circulation operation when stoping hot water supply, wherein a storage tank configured to store a cleaning agent used in a cleaning operation of cleaning an inside of the pipe of the hot water supply device is provided at the bypass pipe.

Abstract: A water heating apparatus includes: a water heating circuit; a heater for heating the water heating circuit; and a controller for controlling the water heating apparatus. The water heating circuit includes a heat exchanger for heating a fluid including water and hot water, and a pipe for supplying the fluid via the heat exchanger. The controller is configured to drive the heater in a cleaning mode in which a cleaning liquid for cleaning an inside of the heat exchanger is supplied to the heat exchanger through the pipe.

Abstract: An exhaust structure for a combustion apparatus includes a combustion apparatus, an exhaust tube, an exhaust pipe, an exhaust adapter, and a fixing member. The exhaust tube is connected to the combustion apparatus at the one end portion. A part of the exhaust tube on a side of the other end portion is inserted into the exhaust pipe. The exhaust adapter has an annular shape surrounding a through hole, and is attached to an outer circumferential surface of the exhaust tube and to an inner circumferential surface of the exhaust pipe by inserting the exhaust tube into the through hole. The fixing member is formed of an elastic body, attached to the exhaust pipe at a position close to the combustion apparatus relative to the exhaust adapter, and fixes the exhaust tube to the exhaust pipe while being attached to the outer circumferential surface of the exhaust tube.