As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS NOT GROUNDED: IN CRUISE, MOMENTARILY RECEIVED AFT LAVATORY SMOKE WARNING ECAM. FLIGHT ATTENDANT REPORTS THAT AFT LEFT LAVATORY TEMPERATURE WAS VERY WARM ESPECIALLY UNDER SINK WATER HEATER. SHUT OFF LAVATORY AND BLOCKED FOR REMAINDER OF FLIGHT. REMOVED AND REPLACED AFT LAVATORY LEFT SMOKE DETECTOR FILTER IAW AMM 26-17-15. OPS CHECK WATER TEMPERATURE NORMAL IAW AMM 38-12-00.