To prevent the freezing of the water in a tank and feed hot water for washing hands.

A sub-tank 61 and a hot-water tank 13A are connected by a hot-water feed pipe 66 and a cold-water feed pipe 63. A switching unit 81 selectively feeds hot water to the sub-tank 61 or a hand washing pipe 82. When the hot-water circulation mode is set on via the operation of a switch 76, a motor 71 is driven at every fixed time, hot water is circulated between the sub-tank 61 and the hot-water tank 13A, and the freezing of the water of the sub-tank 13A is prevented. When the feed path of hot water is switched to the hand washing pipe 82 from the sub-tank 61 via the operation of a hand washing knob 84, hot water can be utilized as the hand washing water.