Dialysis machine and cleaning method for the dialysis machine

A dialysis treatment unit (1) having a preparation unit (2) for dialysis solution having at least one connecting means (8), by means of which a concentrate line (19) of the preparation unit (2) can be connected to a line means (9) of a central concentrate supply system (10), having at least one valve (5, 6) in the concentrate line (19), by means of which the transfer of concentrate out of the connecting means (8) and into the concentrate line (19) can be controlled by a control unit (3) through the opening of the valve (5, 6), characterized in that the control unit (3) is configured to cause the transfer of concentrate out of the connecting means (8) and into the concentrate line (19) during a rinsing or cleaning process in order to prevent crystal binding in the connecting means (8).