The invention relates to an arrangement for detecting and locating a leakage in a water pipe system, having a water treatment system, having a pump, having a supply line and a drain, having at least one circulation line connected to the supply line and the drain, having at least one inlet valve, at least one outlet valve and at least one pressure sensor in at least one circulation line and/or the supply line and the drain, wherein the inlet valve and the outlet valve are electrically controllable, having control means for controlling the inlet valves and the outlet valves, having detection means for detecting the timewise development of the measured values of the at least one pressure sensor, with evaluation means for evaluating the timewise development of the pressure change and for comparing the amount of the pressure change with a limit value, and with output means for the output of a leakage indicating indication signal if the amount of the pressure change exceeds the limit value. This arrangement solves the technical problem of improving the detection and, if necessary, location of a leakage.