As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIR TURN BACK, PRIOR TO DEPARTURE WE WERE ADVISED BY MAINTENANCE CONTROL THAT THE TOILET WOULD SUCTION FEED ABOVE 16000€™ DUE TO MEL. IT DID NOT WORK REF T3F18E0099P47 FOR CORRECTIVE ACTION REMOVED AND REPLACED LAV VACUUM BLOWER WITH REF TO MM 38-32-06/401 CONFIG 1.