PURPOSE: To improve the added value of a system by constituting the system that a repeater collecting information of a hot water supply via a power source for lighting distribution wire and a remote controller supervising and controlling transmit and receive a command signal and an information signal.

CONSTITUTION: The repeater 9 modulates an output of hot water sensors 11, 12, the result is carried on a lighting distribution wire through a coupler 17, then a command signal from the lighting wire is demodulated and it is compared with an information signal from the sensors 11, 12, the result is given to driver circuits 19, 20 for a three-way valve 7, etc. so as to drive the mechanism. Then the repeater 9 is operated by a remote controller 10 of another room. The remote controller 10 transmits/receives a signal with the lighting wire power supply via the coupler 25, the received information is demodulated, amplified and the information is displayed on a hot water amount display device 28 and a hot water temperature display device 29. The command of the user becomes a command signal via a user mode setter 21, the signal is modulated and transmitted to the repeater 9 via the coupler 25 and the lighting wire.