As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IAD FLT 3153 THE CREW REPORTED A BLEED NR 1 OVERTEMP INDICATION IN FLIGHT DURING ICING CONDITIONS. THE AIRCRAFT DIVERTED INTO CLE AND LANDED WITHOUT INCIDENT. MAINTENANCE INSPECTED AND REPLACED THE NR 1 FAN AIR CONTROL THERMOSTAT. OPERATIONAL CHECKS WERE GOOD.