What was found
RIGHT MAINT GEAR GREEN LIGHT DID NOT ILLUMINATE FOR LANDING. AIRCRAFT COMPLETED FLYBY TO VERIFY GEAR DOWN. AMBER ALERT DECLARED. UNEVENTFUL LANDING. *S/D* MAINTENANCE FOUND WATER SYSTEM FILL VALVE IN OPEN POSITION, INHIBITING PRESSURIZATION OF THE WATER SYSTEM. THE LAV WATER HEATER MAY NOT HAVE FILLED UP WITH WATER AFTER SERVICING, ALLOWING TRAPPED AIR TO CAUSE AN OVERHEAT CONDITION IN THE FWD LAV WATER HEATER, AND CONSEQUENTLY TRIPPING THE OVERHEAT BREAKER. WITHOUT WATER IN THE HEATER TO ACT AS A HEAT-SINK, THERE MAY HAVE BEEN A HIGHER TEMP SPIKE IN THE HEATING ELEMENTS BEFORE TRIPPING, WHICH RESULTED IN HEATER DAMAGE AND THE ELECTRICAL ODOR. REPLACED WATER HEATER.