What a GFCI does and why you might need to replace one

A GFCI outlet (ground fault circuit interrupter) is a safety device that cuts power in milliseconds if it detects water or a short circuit. Unlike a regular outlet, it has a "Test" and "Reset" button on its face. You'll find them in kitchens, bathrooms, garages, and anywhere near water. When a GFCI stops resetting or won't hold power, it's time to replace it.

Replacement is a straightforward job for a homeowner with basic comfort around electrical outlets. You don't need to call an electrician unless the outlet is part of a larger circuit problem or you're unsure about the wiring. The whole job takes about 15 minutes once you've turned off power at the breaker.

Key Takeaways

  • Turn off power at the breaker panel before you touch anything inside the outlet box, and test the outlet with a voltage tester to confirm power is off.
  • A GFCI outlet has two sets of terminals: "Line" (where power comes in) and "Load" (which protects downstream outlets), so note which wires go where before you disconnect them.
  • Buy a replacement GFCI rated for the same voltage and amperage as the one you're removing—usually 120V, 15A for standard household outlets.
  • If the outlet is in a wet location like a bathroom or outdoor area, use a weather-resistant GFCI cover or a GFCI outlet with a built-in cover.

Turn off power and confirm it's really off

Go to your breaker panel and flip the breaker that controls the outlet you're replacing. If you don't know which breaker it is, flip breakers one at a time and test the outlet with a lamp or phone charger until it stops working. Once you've found it, flip it to the "Off" position and leave it there.

Before you touch anything inside the outlet box, use a non-contact voltage tester (a handheld tool that beeps near live wires). Hold it near the outlet terminals. If it beeps or lights up, power is still on—go back to the panel and flip the correct breaker. If it stays silent, you're safe to proceed. This step takes 30 seconds and prevents a shock.

Remove the old GFCI outlet

Unscrew and remove the cover plate. You'll see two screws holding the outlet itself to the box—one at the top and one at the bottom. Unscrew both and gently pull the outlet out of the box. Don't yank it; the wires are still attached.

Look at the terminals on the back of the outlet. You'll see four brass screws (two labeled "Line," two labeled "Load") and one green screw for the ground wire. The "Line" terminals are where power enters; the "Load" terminals protect additional outlets downstream on the same circuit. Write down or photograph which wires connect to which terminals before you disconnect anything. This takes one minute and saves confusion.

Loosen each terminal screw and pull the wire out. There are usually three wires: black (hot), white (neutral), and bare copper or green (ground). Set them aside. If the outlet is the only one on the circuit, only the "Line" terminals will have wires. If it protects other outlets, both "Line" and "Load" will be connected.

Install the new GFCI outlet

Check the voltage and amperage rating on your new GFCI. It should match the old one—almost always 120V, 15A for standard household outlets. If you're unsure, take a photo of the old outlet to the hardware store and match it.

Insert the wires into the new outlet in the same order they came out of the old one. The black wire goes to the brass screw on the "Line" side (usually the right side when the outlet faces you). The white wire goes to the silver screw on the "Line" side. The ground wire (bare copper or green) goes to the green screw. Tighten each screw firmly—snug, not over-tight. If the old outlet had wires in the "Load" terminals, connect those the same way on the "Load" side of the new outlet.

Push the outlet back into the box and screw it in at the top and bottom. Screw the cover plate back on. Turn the breaker back on at the panel.

Test the new outlet

Plug a lamp or phone charger into the outlet to confirm it has power. Press the "Test" button on the GFCI—the outlet should cut power and the lamp should go off. Press "Reset"—power should return and the lamp should come back on. If both happen, the outlet is working correctly.

If the outlet doesn't have power after you turn the breaker back on, turn the breaker off again and double-check that all wires are tight in their terminals. If power comes back but the Test button doesn't cut it, the outlet may be faulty—replace it with another new one.

GFCI outlets in wet locations need extra protection

If the outlet is in a bathroom, kitchen, garage, or outdoor area, building code requires GFCI protection. A standard GFCI outlet provides that protection, but the outlet itself can be damaged by moisture over time. Use a weather-resistant cover plate (a plastic box that closes over the outlet when nothing is plugged in) or buy a GFCI outlet with a built-in cover. These cost a few dollars more but last longer in damp conditions.

Outdoor outlets should be in a weatherproof box mounted under an eave or overhang. If you're replacing an outdoor GFCI, use a cover rated for outdoor use and check that the box itself isn't cracked or corroded.

When to call a professional electrician

Call an electrician if the breaker trips when ready after you turn it back on—this usually means a short circuit in the wiring, not the outlet. Also call if you're unsure which wires go where, if the outlet box is damaged, or if you find more than three wires in the box (a sign the outlet may be part of a more complex circuit).

If the GFCI outlet keeps tripping even after replacement, the problem is likely a fault in the wiring downstream, and an electrician should inspect the circuit. Don't ignore repeated tripping—it's a safety signal.

Frequently Asked Questions

Can I replace a GFCI with a regular outlet?

No. Building code requires GFCI protection in kitchens, bathrooms, garages, and wet areas. If you remove a GFCI, you must replace it with another GFCI or install a GFCI breaker in the panel. A regular outlet won't provide the shock protection those locations need.

What if I connect the wires to the Load terminals instead of Line?

The outlet will work, but it won't protect any downstream outlets on the circuit. If this is the first outlet on the circuit and you want it to protect others, use the Line terminals. If it's the last outlet or the only one, it doesn't matter—use Line for consistency.

Do I need to turn off the breaker if I'm just replacing the cover plate?

No. The cover plate is plastic and doesn't conduct electricity. You can swap it with the power on. But if you're touching the outlet itself or the wires, always turn off the breaker first.

How often do GFCI outlets need to be replaced?

A GFCI outlet typically lasts 15 to 25 years, but moisture, power surges, and repeated tripping can shorten that. If it stops resetting or trips constantly, replace it. Some people replace them every 10 years in wet areas as preventive maintenance.

What's the difference between a GFCI outlet and a GFCI breaker?

A GFCI outlet protects only that outlet and any outlets downstream on the same circuit. A GFCI breaker in the panel protects the entire circuit. Breakers are more expensive but protect everything on that circuit at once. Outlets are cheaper and let you protect only the areas that need it.