As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
NO HEAT FLOW INTO THE CABIN WHEN IN FLIGHT. FOUND THAT WELD THAT ATTACHED THE CONTROL ROD TO THE VALVE PLATE HINGE CRACKED & BROKEN CAUSING THE VALVE PLATE TO NOT FUNCTION AS DESIGNED TO OPEN OR CLOSE ALLOWING HOT AIR FROM ENTERING THE CABIN.