To enable a stagnation sensing system of stagnant water to easily grasp the stagnation time of stagnant water in a water pipe.
A flowing water sensing means 52 is attached to a water pipe at the draw side of a water purifier. The cock-shutting state of a stop cock is sensed with a sensing means 54, and a period of the cock-shutting state is calculated with a calculation means 58 to display it as the number of stagnation days. When the number of stagnation days becomes equal to or more than a first stagnation time (for example, one day), the details of a subtracting counter 62 are displayed. When the stagnant water is discharged from the water pipe, the subtracting counter is used as a standard of the amount of the discharged water. When the number of stagnation days becomes equal to or more than a second stagnation time (for example, one week), the subtracting counter is operated, and at the same time, an indicating lamp is flashed. The flashing continues until the value of the counter becomes zero. A period until the value becomes zero, namely a flashing period, is a discharged water treatment period, and when the lamp goes out, the stagnant water in the water pipe can be almost discharged from the stop cock. Thereby the stagnant water is discharged completely, and tap water is not wasted.
NISHIKAWA HIROYUKI
ISHIKAWA TETSUO
Eiji Sasaki