As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IAH - DURING PREFLIGHT INSPECTION THE CREW REPORTED SMOKE IN THE COCKPIT WHEN THE PACKS ARE TURNED ON. MAINTENANCE INSPECTED THE AIRCRAFT AND FOUND SMOKE TO BE WATER VAPOR. MAINTENANCE CLEANED THE SPRAY NOZZLE ON THE NUMBER ONE PACK WATER SEPARATOR, OPERATIONALLY TESTED WITH NO DEFECTS OR MIST/SMOKE NOTED, AND THE AIRCRAFT WAS APPROVED FOR RETURN TO SERVICE.