In fact, some act within 1/30 of a second, which is quick enough to prevent an electric shock from reaching your heart. GFCI outlets are required to be installed anywhere moisture is present including bathrooms, kitchens, laundry rooms, and wet bars, although they can be used anywhere in the home as they function as normal outlets. GFCI outlets typically work reliably for many years, but they can fail and lose their primary safety function. GFCIs also can be wired improperly, disabling the safety feature of the outlet. That’s why all GFCI outlets are equipped with buttons for testing their safety function. The test takes just a few seconds and doesn’t require shutting off the circuit power. If a GFCI fails this simple test, replace the outlet as soon as possible.

Testing a GFCI Outlet by Hand

Using a GFCI Tester

Another way to test a GFCI outlet is to use a GFCI outlet tester. This is a simple electrical device that has LED lights and, sometimes, a display screen to indicate various test results. The tester can tell you whether the outlet is wired correctly and can also identify several wiring problems, including open ground, reversed polarity, an open hot or neutral, and a reversed hot and ground. Alternatively, you can check for the presence of voltage with a voltage tester or a multimeter. This test also should indicate no power. The tester also has a test button that trips the GFCI to check the safety function. This has the same result as pushing the test button on the outlet face. A GFCI outlet tester is inexpensive and can test standard (non-GFCI) outlets as well as GFCIs, making it a handy tool to have in your electrical tool kit.

How Often You Should Perform the Test

Electrical safety experts and device manufacturers recommend testing GFCI outlets once a month. This may seem unnecessarily frequent, but the safety function of GFCIs can fail anytime and without notice, so there’s often no indication of a problem. In many cases, a GFCI will continue to provide power to plugged-in devices even if the GFCI safety device has failed.

Testing GFCI Circuit Breakers

GFCI protection can be provided by circuit breakers in addition to outlets. When a GFCI circuit breaker is used, it provides GFCI protection to all of the wiring and devices on the entire circuit. By contrast, a GFCI outlet may be wired to protect only itself, or it can be wired to protect itself and all other devices that are downstream on the same circuit. It cannot protect any devices upstream or between the outlet and the power source feeding the outlet. GFCI circuit breakers also should be tested monthly. The test is similar to testing GFCI outlets. You simply open the door on your home’s service panel (breaker box) and press the test button on the GFCI breaker. This should cause the breaker to trip, shutting off all power to the entire circuit. To reset the breaker and restore power to the circuit, flip the breaker handle off, then switch it on.