As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT 651 TPA-SJU, INFLIGHT CREW REPORTS FWD LAVATORY HOT WATER HEATER EXTREMELY HOT, SMOKING IN FLIGHT. TURNED OFF HEATER AND ALL INDICATIONS FIXED. PERFORMED TSM 24-00-00-810-823 FOR ELECTRICAL BURNING SMELL IN CABIN. INSPECTED LAVATORY. FOUND WATER HEATER AT FAULT. HEATER PLACED ON NEF N25-40-01 MDDR 164244. NOTE: SUPPLEMENTAL INFO WILL BE FILED AFTER HEATER REPLACEMENT.