As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CLIMB CREW WAS UNABLE TO CONTROL CABIN TEMPERATURE. EMERGENCY DECLARED. LANDING UNEVENTFUL. AIRCRAFT WAS GROUNDED. MAINTENANCE FOUND THE RIGHT ZONE TEMPERATURE CONTROL VALVE STUCK PARITALLY OPEN. REMOVED AND REPLACED THE CONTROL VALVE IAW AMM 21-51-10. OPERATIONAL AND BITE TESTED NORMAL.