As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IAD-SCE - FLT 6326 - DURING CLIMBOUT, THE DUCT OVERTEMP LIGHT ILLUMINATED IN FLIGHT AND WOULD NOT EXTINGUISH WITH FLOWS SHUT OFF. ACFT RETURNED TO IAD WITH NO FURTHER INCIDENTS. MAINTENANCE REPLACED THE DUCT CONTROL UNIT. ACFT WAS RELEASED AND APPROVED FOR RETURN TO SERVICE. (W)