What was found
(EMERGENCY DECLARED) AT CRUISE AFT FA NOTED LAV G WAS VERY HOT INSIDE SINK AREA WAS VERY HOT TO TOUCH. CABINET BELOW SINK WAS OPENED AND VERY STRONG ELEC BURN SMELL OCUED + CONTINUED ALL THE WAY UNTIL LANDING. FA TOUCHED THE WATER HEATER AND WAS EXTREMELY HOT GALLEY WALL NEXT TO LAV WAS VERY HOT TO THE TOUCH. AFTER LANDING FIREMAN RECORDER 130 ON TH HOT WATER TEMP + 108 ON THE COLD TEMP. FOR REFE, OTHER LAV SHOWED 80 ON THE HOT WATER. REMOVED AND REPLACED HOT WATER HEATER IN AFT LAV G IAW AMM 38-12-16-000-001-A OPS CHECK GOOD THIS CLEARS MEL 38-10-01A DMI 108557 MX PROCEDURES REVERSED AND INOP PLACARDS REMOVED.