As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IAH - FLIGHT 2020, DURING CLIMB THE CREW REPORTED A PACK 1 VALVE CLOSED MESSAGE ON EICAS. THE AIRCRAFT RETUIRNED TO IAH WHERE IT LANDED WITHOUT INCIDENT. MAINTENANCE REMOVED AND REPLACED SLEEVE ON THE PACK ONE DUAL TEMP CONTROL VALVE, OPERATIONALLY AND LEAK CHECKED WITH NO DEFECTS, AND THE AIRCRAFT WAS APPROVED FOR RETURN TO SERVICE.