As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED AN AFT AND FORWARD LAVATORY RED WARNING MESSAGE DURING TAKEOFF. THE CREW ELECTED TO RETURN TO DAY WHERE THE ACFT LANDED AND TAXIED TO THE GATE WITHOUT INCIDENT. MAINTENANCE PERFORMED GROUND RUNS AND OPERATIONAL CHECKS. MAINTENANCE REMOVED AND REPLACED THE RT ACM BLEED TEMP SENSOR IN ACCORDANCE WITH THE ACFT MAINTENANCE MANUAL. OPERATIONAL CHECKS WERE GOOD. ACFT WAS RELEASED FOR SERVICE. (S)