A connecting device for connecting a beverage machine with an external liquid delivery system , e.g. a water distribution network, to supply such liquid to said machine , said connecting device having: - an inlet for a fluid connection to said external system ; - an outlet for delivering liquid from said external system via the inlet to said beverage machine ; - a valve arrangement switchable between an open configuration for establishing a fluidic connection between the inlet and the outlet and a closed configuration for interrupting the fluidic connection, such as a valve arrangement comprising at least one valve ; - a control unit for switching the valve arrangement between its open configuration and its closed configuration; and - a sensor arrangement connected to the control unit , the outlet being configured to deliver liquid from said external system into a tank of said machine or of such connecting device , the sensor arrangement comprising a low level sensor for detecting a low level of liquid in said tank and a high level sensor for detecting a high level of liquid in said tank , characterised in that the control unit is configured to switch the valve arrangement in response to a triggering signal from the sensor arrangement , and in that : - the low level sensor for detecting the low level of liquid in said tank is arranged to generate a triggering signal for switching the valve arrangement to the open configuration so as to fill said tank with liquid delivered by the outlet ; and - the high level sensor for detecting the high level of liquid in said tank to generate a triggering signal for switching the valve arrangement to the closed configuration, and in that the control unit is also arranged to switch the valve arrangement into the closed configuration: - when a predetermined period of time has lapsed after switching the valve arrangement into the open configuration, the predetermined period of time being optionally user-adjustable, e.g. to adjust to a flow rate of liquid supplied from said external delivery system and/or to adjust to a maximum storage volume of said tank ; and/or - when a further sensor provides a signal to the control unit that indicates that the high level has been exceeded. - an inlet for a fluid connection to said external system ; - an outlet for delivering liquid from said external system via the inlet to said beverage machine ; - a valve arrangement switchable between an open configuration for establishing a fluidic connection between the inlet and the outlet and a closed configuration for interrupting the fluidic connection, such as a valve arrangement comprising at least one valve ; - a control unit for switching the valve arrangement between its open configuration and its closed configuration; and - a sensor arrangement connected to the control unit , - the low level sensor for detecting the low level of liquid in said tank is arranged to generate a triggering signal for switching the valve arrangement to the open configuration so as to fill said tank with liquid delivered by the outlet ; and - the high level sensor for detecting the high level of liquid in said tank to generate a triggering signal for switching the valve arrangement to the closed configuration, - when a predetermined period of time has lapsed after switching the valve arrangement into the open configuration, the predetermined period of time being optionally user-adjustable, e.g. to adjust to a flow rate of liquid supplied from said external delivery system and/or to adjust to a maximum storage volume of said tank ; and/or - when a further sensor provides a signal to the control unit that indicates that the high level has been exceeded. <EOS>