Hot-water supply system

A hot water supply system setting one of a plurality of water heaters to master, setting another to slave and cooperatively operating a hot water supply operation, comprising:

• an identification number assigning unit which assigns a unique identification number specifying order of priority, to each of the water heaters;
• a mutual communication unit which connects and allows the plurality of water heaters to communicate with each other;
• a plurality of control units, each of which is provided in a different one of the plurality of water heaters, and each of which is configured to perform a master and slave setting process;
• and
• a remote control which is connected to and capable of communicating with each of the water heaters via the mutual communication unit,
• wherein the master and slave setting process includes transmitting prescribed response data to the other water heater via the mutual communication unit at a timing according to its own identification number and different from the timing of the other water heater in a prescribed master and slave setting time period, setting the water heater itself to slave in a case of receiving the response data from another water heater assigned with an identification number having a priority higher than its own identification number in the master and slave setting time period, and setting the water heater itself to master in a case of not receiving the response data from another water heater assigned with an identification number having a priority higher than its own identification number in the master and slave setting time period, and
• wherein the remote control remotely operates the water heater set to master by means of communication via the mutual communication unit.

A method for setting one of a plurality of water heaters to master and setting another to slave, comprising:

• assigning an identification number specifying an order of priority to each of the water heaters using an identification number assigning unit;
• and
• causing each of the water heaters to:
• transmit prescribed response data to another water heater at a timing according to its own identification number and different from a timing of the other water heater in a prescribed master and slave setting period using a transmitter provided in the water heater;
• receive response data from the other water using a receiver provided in the water heater;
• determine whether the receiver receives the response data from the other water heater assigned with an identification number having a priority higher than an own identification number in the master and slave setting time period using a determination element;
• and
• set the water heater itself to slave if a determination by the determination element is positive, and set the water heater itself to master if a determination by the determination element is negative using a setting element.