A321
Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine; Flight Crew Instrument
Time Pressure; Troubleshooting
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Maintenance; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Provided Assistance; Flight Crew Landed in Emergency Condition; Flight Crew Requested ATC Assistance / Clarification; Flight Crew Returned To Departure Airport; Flight Crew Returned To Gate; General Flight Cancelled / Delayed; General Maintenance Action
Procedure; Human Factors; Aircraft
Aircraft had been written up by the previous crew as having a potable water leak of unknown origin. Maintenance Techs did their inspection and could find no leaks or indication of water damage. They filled the water tank and signed the aircraft off for flight. Within 10 minutes of departure flight attendants report water tank was down to 70% and lavatory sinks had no water coming out. Within 25 minutes of departure tank was empty. We called Dispatch and Maintenance. Decision was made to return to ZZZ. Overweight landing was made because we had no idea where the water was leaking to and we did not want to expose ourselves to compounding failures. Advised ATC due to overweight landing. Landing was uneventful. ARFF followed us to the gate as we monitored brake temperatures.We suggest Maintenance review their task card for potable water leak of unknown origin and possibly make revisions.
A321 Check Airman reported an Air Turn Back after maintenance failed to diagnose and correct a potable water system leak that reoccurred next flight.