As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CONT CAB ZONE TEMP LIGHT ON RECALL. GROUNDED - YES. ZONE TEMP CONTROLLER BITE SHOWS HISTORY OF CONT CAB TRIM VALVE. REMOVED AND REPLACED CONT CABIN TRIM VALVE REF B737-800 AMM 21-61-21. OPERATIONAL CHECK AND LEAK CHECK GOOD. CONTROLLER BITE GOOD REF AMM 21-51-00-700-083.