Abstract: A controller performs a first operation in which a heat source device directly or indirectly heats water in a first channel of a heat exchanger and a second operation in which the heat source device directly or indirectly cools the water in the first channel of the heat exchanger after the first operation ends.

Abstract: A controller performs a first operation in which a heat source device directly or indirectly heats water in a first channel of a heat exchanger and a second operation in which the heat source device directly or indirectly cools the water in the first channel of the heat exchanger after the first operation ends.

Abstract: A hot water supply apparatus includes a hot water supply channel. The hot water supply channel includes a heating section configured to heat water and a tank configured to store the water heated by the heating section. The hot water supply channel is configured to execute a first hot water supply operation in a hot water storage state in which a low-temperature layer, a medium-temperature layer, and a high-temperature layer are formed in the tank. The first hot water supply operation includes heating water in the medium-temperature layer to a first temperature by the heating section and supplying the water heated to a hot water supply target.