Abstract: A hot-water supply system includes a switching valve (35) which has a bypass circuit which bypasses the water softening device (30) by directly connecting the water supply pipe (P1) and the inlet pipe (P3) of a hot-water supply device to each other, and a control unit (50). The control unit (50) includes a switching valve drive circuit which switches the switching valve (35) to the mode in which water is supplied from the water supply pipe (P1) to the hot-water supply device (1) via the bypass circuit, based on the determination of the timing of salt replenishment, and a display drive circuit which displays intention, in which salt replenishment is needed, on a display portion (51) of a remote controller (RC).

Abstract: A hot-water supply system includes a switching valve (35) which has a bypass circuit which bypasses the water softening device (30) by directly connecting the water supply pipe (P1) and the inlet pipe (P3) of a hot-water supply device to each other, and a control unit (50). The control unit (50) includes a switching valve drive circuit which switches the switching valve (35) to the mode in which water is supplied from the water supply pipe (P1) to the hot-water supply device (1) via the bypass circuit, based on the determination of the timing of salt replenishment, and a display drive circuit which displays intention, in which salt replenishment is needed, on a display portion (51) of a remote controller (RC).

Abstract: A heat source machine includes: a first emission amount calculation unit 12 which calculates a first carbon dioxide emission amount that is an amount of carbon dioxide emitted to obtain an energy source consumed in a hot-water supply operation; a second emission amount calculation unit 13 which calculates a second carbon dioxide emission amount that is an amount of carbon dioxide emitted to obtain an energy source consumed in a reference heat source machine on an assumption that the reference heat source machine performs the same operation as the hot-water supply operation; and a carbon dioxide emission reduction degree display unit 14 which displays a carbon dioxide emission reduction degree that results from changing to the current heat source machine, according to a difference between the first carbon dioxide emission amount and the second carbon dioxide emission amount.