As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON FLT NR 444 - ATL-ATL - AIR RETURN, STRONG ACRID ODOR IN COCKPIT IN CLIMB-OUT SIMILAR TO ELECTRICAL SMOKE. INSPECTED ELECTRICAL SYSTEM IN AND AROUND FLIGHT DECK AREA AND GALLEY. RAN BOTH ENGINES, FOUND AN OVERHEATED COFFEE MAKER HOT PLATE. REMOVED AND REPLACED COFFEE MAKER, OPS CHECK GOOD.