Patent ID: 8721875

Claim:
A hot-water supply system which includes a remote controller having a display portion, a hot-water supply device and a water softening device, which includes a regeneration salt water supply device, and in which regeneration salt water is supplied from the regeneration salt water supply device, an ion exchange resin of the water softening device is repeatedly regenerated, and soft water is supplied from the water softening device to the hot-water supply device, comprising: a regeneration salt amount determination unit which determines an amount of salt in the regeneration salt water supply device; a switching valve which is positioned at an upstream side of the water softening device, is connected to a water supply pipe which supplies water to the water softening device and a soft water supply pipe which supplies soft water generated by the water softening device to the hot-water supply device, and includes a bypass circuit which bypasses the water softening device by directly connecting the water supply pipe and the soft water supply pipe; and a control unit which controls the switching valve, wherein the control unit includes: a storage unit which stores a salt replenishment reference of the regeneration salt water supply device; a calculation circuit which determines a timing of salt replenishment in the regeneration salt water supply device based on the amount of salt in the regeneration salt water supply device determined by the regeneration salt amount determination unit, and the salt replenishment reference; a switching valve drive circuit which switches the switching valve to a mode, in which the water softening device is bypassed by the bypass circuit and water is directly supplied from the water supply pipe to the hot-water supply device, based on the timing of salt replenishment in the regeneration salt water supply device which is determined by the calculation circuit; and a display drive circuit which displays necessity for replenishment of salt in the regeneration salt water supply device, on the display portion of the remote controller of the hot-water supply system based on the timing of salt replenishment which is determined by the calculation circuit.