As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ZONE TEMP LIGHT ON CONT CAB ON RECALL AFTER START, WOULD NOT RESET. GROUNDED - YES. RELEASED PER MEL 21-21G, FLIGHT DECK PRIMARY TEMP CONT INOP. REMOVED AND REPLACED CONTROL CABIN TRIM MODULATING VALVE IAW B737-800 AMM 21-61-21/401. LEAK CHECK GOOD. OPS CHECK GOOD IAW AMM 21-61-00-700-806-002. CLEARS MEL 21-21G.