As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE FLIGHT CREW REPORTED THAT THE CABIN ENVIRONMENTAL TEMP REMAINED COLD DESPITE A HOT TEMP SELECTED ON THE AUTO-CONTROLLER. THE MAINTENANCE TEAM DETERMINED THAT THE CABIN TEMP CONTROLLER BOX WAS DEFECTIVE. THE CONTROL BOX WAS REMOVED AND A NEW CABIN TEMP CONTROL BOX WAS INSTALLED. FUNCTIONAL CHECKS WERE SATISFACTORY. THE AIRCRAFT WAS RETURNED TO SERVICE.