What a GFI outlet does and why you might need to replace one
A GFI outlet (ground fault interrupter) is a safety device that cuts power when ready if it detects water or a short circuit. Unlike a standard outlet, it has two buttons on the face — a "Test" button and a "Reset" button. When the Reset button pops out, the outlet has tripped and stopped sending power to anything plugged into it.
You need to replace a GFI outlet when it no longer holds a reset, trips constantly without reason, or the buttons are cracked or stuck. A GFI that won't stay reset is a sign the internal mechanism has failed and the outlet cannot protect you anymore. Replacing it is a straightforward job that takes about 15 minutes and requires only a screwdriver and a voltage tester.
GFI outlets are required by electrical code in kitchens, bathrooms, garages, and anywhere within 6 feet of water. If your GFI is in one of these locations and it has failed, replacing it restores that protection for you and anyone else in your home.
Key Takeaways
- Turn off power at the breaker panel before you touch any wires, and use a voltage tester to confirm the power is off.
- Remove the old outlet by unscrewing the two terminal screws and pulling the outlet straight out of the box.
- Connect the new GFI outlet by attaching the black wire to the brass screw, the white wire to the silver screw, and the bare copper wire to the green screw.
- Push the outlet back into the box, screw the cover plate on, and test it with the Test and Reset buttons before you consider the job done.
- If you are uncomfortable working with live electrical wiring or the outlet box is damaged, call a licensed electrician.
Turn off the power and verify it is off
Go to your breaker panel and locate the breaker that controls the outlet you are replacing. The breaker label should tell you which room or circuit it serves — if the label is missing or unclear, you may need to test outlets in that room to find the right one. Flip the breaker switch to the Off position.
Do not assume the breaker switch is enough. Use a voltage tester (a battery-powered device that lights up or beeps when it detects electricity) to confirm the outlet is dead. Plug the tester into the outlet or touch its probes to the screw terminals. If the tester does not light or beep, the power is off and you can proceed safely.
If you do not own a voltage tester, buy one at any hardware store for $10 to $20. It is the single most important safety tool for this job and takes the guesswork out of whether an outlet is live.
Remove the cover plate and unscrew the old outlet
Unscrew the cover plate (the plastic or metal faceplate) and set it aside. You will see the outlet itself, held in the electrical box by two screws at the top and bottom of the outlet frame. Unscrew both of these screws, but do not remove them completely — just loosen them enough that you can pull the outlet forward slightly.
Gently pull the outlet straight out of the box. You will see three wires attached to the back: a black wire (hot), a white wire (neutral), and a bare copper wire (ground). The wires are held by screws on the sides of the outlet. Loosen each screw just enough to slide the wire out — do not force them or you may damage the wire insulation.
Set the old outlet aside. If the wires are very short or the box is damaged, stop here and call a licensed electrician. Damaged boxes or short wires are safety issues that require professional repair.
Connect the new GFI outlet
Before you touch the new outlet, look at the back. You will see six screw terminals: two brass screws on the right side, two silver screws on the left side, and one green screw at the bottom. The brass screws are for the hot (black) wire, the silver screws are for the neutral (white) wire, and the green screw is for the ground (bare copper) wire.
Take the black wire and loosen the top brass screw on the new outlet. Wrap the bare end of the black wire clockwise around the screw post (about three-quarters of the way around), then tighten the screw. The wire should be snug but not so tight that you crush the insulation. Repeat this process with the white wire on the top silver screw and the bare copper wire on the green screw.
If your outlet has two sets of brass and silver screws, you are looking at a load terminals feature — the bottom set protects other outlets downstream on the same circuit. For a straightforward replacement, use only the top set of screws. The bottom set is for advanced installations and you can leave it empty.
Push the outlet back and find it
Carefully push the outlet back into the electrical box, making sure the wires fold neatly behind it and do not get pinched. The outlet should sit flush against the box with no gaps. Once it is seated, screw the two frame screws back in — the ones at the top and bottom of the outlet — and tighten them firmly but not so hard that you crack the outlet body.
Screw the cover plate back on. Make sure it is centered and sits flat against the wall. If the outlet sticks out or the plate does not sit flush, the outlet may not be fully seated in the box — pull it back out and check that the wires are not bunched up behind it.
Test the new GFI outlet
Turn the breaker back on at the panel. Go back to the outlet and press the Reset button — it should click and stay in. Then press the Test button — the Reset button should pop out when ready, cutting power to the outlet. If the Test button does not trip the Reset button, the outlet is faulty and you should replace it again.
Press Reset again to restore power. Plug a lamp or phone charger into the outlet to confirm it is working. If the outlet does not power the device, check that the breaker is fully on and try the Reset button again. If it still does not work, turn the breaker off and check that all three wires are connected tightly to their screws.
Once the outlet is working and the Test button trips it reliably, the job is complete. A working GFI outlet will protect you from electrical shock in wet areas and is one of the most important safety devices in your home.
When to call a licensed electrician
Stop and call a professional if the outlet box is cracked, corroded, or damaged in any way. A damaged box cannot hold the outlet safely and may allow water or pests inside the wall. Also call if the wires are too short to reach the screw terminals comfortably — forcing short wires creates stress on the connections and is a fire hazard.
If you are not comfortable working with electrical wiring, or if the outlet does not work after you have followed these steps, a licensed electrician can finish the job safely. The cost is usually $100 to $200 for a single outlet replacement, and the peace of mind is worth it.
Frequently Asked Questions
Can I replace a GFI outlet with a regular outlet?
Not in areas where code requires a GFI. Kitchens, bathrooms, garages, and outdoor outlets must have GFI protection by law. You can use a regular outlet only if you install a GFI breaker in the panel instead, but that is a job for a licensed electrician.
What if the outlet box is too shallow for the new outlet?
Shallow boxes are common in older homes. You can buy an outlet spacer ring (a thin metal ring that sits between the outlet and the box) to add depth. If the box is still too shallow after that, call an electrician — forcing an outlet into a box that is too small is a fire hazard.
Do I need to turn off the whole house to replace one outlet?
No. You only need to turn off the breaker that controls that specific circuit. If you are unsure which breaker it is, use a voltage tester to check the outlet before you start — that is safer and faster than flipping breakers.
Why does my new GFI outlet keep tripping?
A new GFI that trips constantly usually means there is a short or moisture somewhere on that circuit. Unplug everything from the outlet and nearby outlets on the same circuit, then press Reset. If it stays reset, plug devices back in one at a time to find which one is causing the trip. If it trips even with nothing plugged in, call an electrician — there may be a fault in the wiring.
Can I replace a GFI outlet myself if I have never done electrical work?
Yes, as long as you turn off the breaker, use a voltage tester to confirm the power is off, and follow the wire colors carefully. The job is simpler than it sounds because you are just moving three wires from one outlet to another. If you feel uncertain at any point, stop and call an electrician.