How to test GFCI outlets
Updated . By the OakTend team.
A GFCI (ground fault circuit interrupter) outlet cuts the power almost instantly when current leaks where it should not, such as through a person. Its built-in test and reset buttons tell you whether it still does that.
Why it matters
GFCIs guard the places where power and water meet: kitchens, bathrooms, laundry sinks, garages and outdoor outlets. A GFCI that has failed still looks and works like a normal outlet, so the only way to know is to test it. In an older house, some of those spots may have no GFCI at all, because the requirement arrived room by room between 1973 and 2005.
Steps
- Plug a lamp into the GFCI outlet and turn it on.
- Press the TEST button. The lamp should go off.
- Press the RESET button. The lamp should come back on.
- Plug the lamp into any other outlets on the same circuit and repeat, because one GFCI can protect outlets downstream of it.
- Do the same at every GFCI: kitchen, bathrooms, laundry, garage and outside.
- Write down any outlet that failed either step.
When to call a pro
If the lamp stays on after you press TEST, the CPSC says the GFCI is not working or was not installed correctly. If it will not reset, it needs replacing. Either way, call a licensed electrician.
Safety
Treat a GFCI that fails the test as giving no shock protection at all, and keep water and outdoor tools away from it until it is fixed.
Go deeper
General information, not professional advice. Your equipment's manual comes first when it says something different.
Sources
- U.S. Consumer Product Safety Commission: GFCI fact sheet
Test every GFCI monthly, after installation and after a power failure; the lamp test and what a failed test or failed reset means; when GFCIs became required outdoors (1973), in bathrooms (1975), garages (1978), kitchens (1987) and at laundry and utility sinks (2005).