Hot water supply system, server and non-transitory computer readable recording medium

A hot water supply system, comprising:

• a hot water supply device which can be connected to an external communication network via a communication repeater;
• and
• a server which is connected to the external communication network and controls the hot water supply device based on a request from a mobile terminal device;
• wherein the server
• obtains, in pairing processing of associating the mobile terminal device which remotely controls the hot water supply device with the hot water supply device, identification information of the communication repeater to which the mobile terminal device is connected, and stores the identification information in a storage portion along with pairing information, and
• performs control to determine conditions of the remote control based on whether the identification information of the communication repeater stored in the storage portion in association with the hot water supply device being a remote control destination matches identification information of a communication repeater received from the mobile terminal device in the communication, when the communication of the remote control to the hot water supply device is received from the mobile terminal device.