As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IN FLIGHT THERE WAS SMELL OF SMOKE IN CABIN AT ROW 30, ACFT LT. SMELLED LIKE ELEC SMOKE ACCORDING TO CABIN CREW. A CUSTOMER SAID SOME SMOKE FROM A SIDE WALL VENT AT ROW 30. FOUND MID DOOR AREA HEATER, IN CEILING, WITH BURNED ELEMENTS. HEATER REPLACED ON LOG PAGE 8140054.