Troubleshoot a ground fault circuit interrupter by checking the age of the unit, checking for short circuits in the wiring, and checking for problems with the wiring. If the GFCI plugs in a home are old or trip more than usual, the plug becomes worn and requires replacement. GFCI plugs for heaters or hair dryers are more likely to fail due to excess wear, but with time, any of the units reach the end of their useful life.
If you have recently replaced a GFCI plug yet it continues to trip, there could be a short circuit in the wiring. Test the unit by turning off the power to the circuit at the breaker, removing the plug from the box and disconnecting the black, white and ground wires from the outlet. Use a multimeter or ohmmeter to test the black and white wires and the bare ground wire for continuity. Any reading other than infinity signifies a circuit leak that requires repair.
Electricians install a single GFCI outlet to provide protection for several plugs along the circuit. The GFCI unit has connectors with markings for line and load. The line connectors are for the wires from the circuit breaker box while the load connectors are for the additional outlets. If the wiring is not correct, the outlet trips.