PURPOSE: To prevent the power charge from raising by providing a flow switch in piping and stopping the operation of a pump when the flow switch was turned off but a pressure switch is still turned on even after a predetermined time has elapsed.

CONSTITUTION: A flow switch 1 is provided on the way of piping 2 and the water flow through the piping 2 is stopped by closing a faucet 6. When the flow switch 1 was turned off but a pressure switch 3 is still turned on to operate a submersible pump 4 even after a predetermined time has elapsed, this submersible pump 4 is forcibly stopped to operate. The submersible pump 4 is thereby not required to operate uselessly, so the power charge can be prevented from raising.