As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT#20, LHR-JFK (ETOPS).' AFT TEMP SENSOR READING NOTABLY WARMER THAN ACTUAL WAS ABLE TO MAINTAIN AN ACCEPTABLY COMFORTABLE TEMP BY ADJUSTING FLT DECK CONTROLS; ACCOMPLISHED RESET OF TEMP CONTROL SYSTEM AND OPS CHECK. CFOS CHECK GOOD REF AMM 21-63-00-710-004. CABIN TEMP IN AFT FELT NORMAL W/SW IN CM POSITION IN COCKPIT.'