As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LHR - FLIGHT ATTENDANT REPORTED NUMBER ONE OVEN HAS BURNING SMELL AND SMOKES WHEN USED. FLIGHT LANDED LHR WITHOUT INCIDENT. FOUND BURNT FOOD IN FAN AREA OF NUMBER ONE OVEN. DEFERRED OVEN INOPERATIVE. REPLACED NUMBER ONE OVEN AT ORD ON 10/14/2012. SYSTEM GROUND CHECK NORMAL OPERATION.