As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT 5306, STL TO EWR. DURING CLIMB AT FL150 THE AIRCRAFT ENTERED LIGHT ICING. THE ANTI-ICING SYSTEM ACTIVATED NORMALLY THEN AFTER A FEW SECONDS THE CREW RECEIVED A BLEED 1 OVERTEMP MESSAGE ON EICAS. THE QRH WAS FOLLOWED AND IT WAS DECIDED TO RETURN TO STL. DURING THE RETURN TO STL THE BLEED 1 OVER-TEMP MESSAGE WENT AWAY. MAINTENANCE REPLACED THE PRECOOLER FOR BLEED SYSTEM 1 AND THE AIRCRAFT OPERATED NORMALLY.