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How often should you test GFCI outlets?

Updated

Short answer

Test the GFCI outlets once a month. A GFCI is the outlet with the test and reset buttons on its face, found in bathrooms, kitchens, garages, basements and outdoors, and its job is to cut the power in a fraction of a second if electricity starts going somewhere it shouldn't, like through a person. Pressing test on each one takes 5 to 10 minutes for a whole house and costs nothing.

Why it matters

Ordinary breakers protect wires from overheating. They trip at a level of current that would kill someone many times over. A ground fault circuit interrupter watches for a different thing: a tiny imbalance between the current going out through one wire and coming back through the other, which means some of it is leaking out of the circuit, often through water and a hand. It trips at a current so small you'd barely feel it, and it does so in less time than a heartbeat.

The electronics that do this wear out. A GFCI in a damp bathroom or an outdoor box can fail after years of humidity and power surges, and a failed one usually keeps delivering power while having quietly stopped protecting anyone. The test button is the only way to find out. It creates a deliberate small fault, and a working outlet clicks off.

When to do it more often

Monthly is the floor, and there's no condition that calls for more frequent testing in the index. There are events that call for a test outside the schedule: after a lightning storm or a power surge, which can damage the electronics, after any electrical work in the house, and when you move in somewhere new. An outdoor GFCI that spends the winter in a wet box deserves a test at the start of each season too.

What you need

Nothing. The outlet has its own test and reset buttons, and a lamp or a phone charger to confirm the power is off and back on is the only extra.

Steps at a glance

  1. Plug a lamp into the GFCI outlet and turn it on.
  2. Press the test button. The reset button should pop out and the lamp should go off.
  3. Press reset. The button should click in and the lamp should come back on.
  4. Check the other outlets in the same room, since a single GFCI often protects several ordinary outlets after it, and those should go dark with it.
  5. Repeat for every GFCI in the house, including the garage, the basement and outside.
  6. Note any outlet that fails either step.

You're done when every GFCI cuts the power on test and restores it on reset.

Signs it's overdue

  • The test button doesn't cut the power.
  • The reset button won't stay in, or the outlet won't reset at all.
  • The outlet is dead with reset pressed, which may be a tripped GFCI upstream or a failed one here.

DIY or pro

Testing is an easy job and the outlet is designed for it. Press, listen, press again. If a GFCI trips on its own now and then, that's often the outlet doing its job on a damp appliance or a worn cord, so unplug things one at a time before blaming the outlet.

A GFCI that fails the test needs replacing, and that's an electrician's job unless you're comfortable working in an outlet box with the breaker off. An electrician charges $100 to $200 to replace one outlet, and will check that the outlets downstream are wired through it properly. Replacing a failed GFCI with an ordinary outlet to make the problem go away leaves everything on that circuit unprotected.

Safety

  • Electricity: the test itself is safe, since the outlet is built for it. The danger is a failed GFCI left in service. An outlet that won't trip on its test button offers no shock protection, so stop using it for anything near water until it's replaced. Don't open the outlet box yourself unless the breaker is off and you've confirmed the outlet is dead.

FAQ

What does a GFCI outlet do?

It cuts the power within a fraction of a second if current leaks out of the circuit, which is what happens when electricity goes through a person. It protects people, where a breaker protects wires.

How do I test a GFCI outlet?

Press the test button. The power should cut off and the reset button should pop out. Press reset, and the power should come back.

Why does my GFCI keep tripping?

Something plugged into it, or into an outlet downstream of it, is leaking current. Unplug appliances one at a time to find it. If it trips with nothing plugged in, the outlet or the wiring has a fault.

How long do GFCI outlets last?

They wear out, especially in damp places. The monthly test is how you find out when one has stopped working, since a failed outlet usually still delivers power.