As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
COCKPIT TEMP CONTROL ERRATIC IN AUTO. TRIM VALVE CYCLES FULL OPEN AND CLOSED. COCKPIT TEMP HOT. TEMPERATURE CONTROLLED IN MAN MODE ONLY.(<P>TRANSFER TO MDDR # 155413 CAT "C" PER DDG 21-61-02-03. DUE 29OCT21. PLACARDS INSTALLED.</P> / <P>LOG PAGE 1480331: REMOVED AND REPLACED CABIN ZONE TEMP CONTROLLER IAW 21-61-03. OPS CHECK GOOD. THIS CLOSES MDDR 155413.</P>)