As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
BURNING PLASTIC ODOR IN COCKPIT. FOUND REMAINDER OF SHIPPING PLUG IN TEMP CONTROL VALVE AND DUCT. DUCT IS IMPREGNATED WITH MELTED PLASTIC FULL LENGTH FROM DUAL HEAT EXCHANGER TO TEMP CONTROL VALVE. REMOVED AND REPLACED TEMP CONTROL VALVE, RECIRCULATION FILTERS, DISPLAY FILTERS, AND PIPE ASSY.