FREEZING PREVENTION METHOD FOR WATER PIPE

PURPOSE:To surely prevent water from being frozen by detecting water temperature within a water pipe at its downstream side by a temperature sensor, conditioning the pipe into a drain hole one for the specified period of time with a motor driven drain hole plug operated when the temperature is less than a specified one, and thereby restoring the pipe to a water supply condition again with a drain hole plug operated again. CONSTITUTION:The temperature of water within the exposed section Po of a water pipe is detected by a temperature sensor 3 at the downstream side of a motor driven drain hole plug 4, and the pipe is conditioned to a drain hole one for the specified period of time with a drain hole plug 4 operated when the temperature is less than a specified one, In the second place, water low in temperature within the exposed section Po from the drain hole plug 4 to a faucet C is then discharged. Water comparatively high in temperature within the buried section Pi of the water pipe at the upstream side of the motor driven drain hole plug 4 is supplied to the faucet C by restoring the pipe to a water supply condition with the drain hole plug 4 operated again. By this constitution, water within the water pipe from the drain hole plug 4 to the faucet C can thereby be prevented from being frozen.