What You Need to Do Before You Start
Replacing a plug outlet is a task most homeowners can do safely in under an hour, but it requires you to turn off power to that outlet first. You will need a flathead screwdriver, a Phillips screwdriver, a voltage tester (a cheap one costs $5 to $10 at any hardware store), and the new outlet itself. The voltage tester is not optional—it is how you confirm the power is actually off before you touch anything inside the box.
Before you buy a new outlet, look at the one you are replacing. Standard outlets in most homes are 15-amp, 120-volt outlets. If your outlet has two vertical slots of equal size, it is a standard outlet. If one slot is slightly larger, it is a polarized outlet (also standard). Bring a photo to the hardware store if you are unsure. Do not guess on this—installing the wrong outlet type can damage appliances or create a fire hazard.
Key Takeaways
- Always turn off the breaker that controls the outlet and test it with a voltage tester before touching any wires inside the outlet box.
- The hot wire (usually black) connects to the brass screw, the neutral wire (usually white) connects to the silver screw, and the ground wire (usually green or bare copper) connects to the green screw.
- Loosen each screw just enough to slide the wire out, then slide the new wire in and tighten firmly—wires that are too loose cause outlets to stop working or overheat.
- Push the outlet straight into the box and screw the mounting screws hand-tight first, then use the screwdriver to tighten them evenly so the outlet sits flush with the wall.
Locate the Breaker and Turn Off Power
Go to your electrical panel (usually in a basement, garage, or utility closet) and find the breaker that controls the outlet you are replacing. Breakers are labeled, though the labels are often faded or wrong. If you are not sure which one controls your outlet, turn off breakers one at a time and have someone test the outlet with a lamp or phone charger until it stops working. Write down the breaker number.
Flip that breaker all the way to the OFF position. The switch should move past the center point and stop on the OFF side. Some breakers are stiff—use steady pressure, not a hard jab. Once it is off, go back to the outlet and plug in a lamp or phone charger to confirm there is no power. If the device does not turn on, the power is off. If it does turn on, go back to the panel and try the next breaker.
Test the Outlet with a Voltage Tester
Even after you turn off the breaker and test with a lamp, use a voltage tester on the outlet itself. This is the single most important safety step. A voltage tester is a small handheld device with two metal probes. Plug it into the outlet—if the light comes on or it beeps, power is still reaching that outlet and you should not proceed. Go back to the panel and check the breaker again.
If the voltage tester does not light up or beep, the outlet is safe to work on. Keep the voltage tester in your hand while you work. If you accidentally touch the breaker for a different circuit, you want to know when ready. Test again before you touch any wires inside the box.
Remove the Old Outlet
Unscrew the cover plate and set it aside. You will see the outlet itself, held in the box by two screws at the top and bottom. Use your Phillips screwdriver to remove these two mounting screws. The outlet will pull out slightly, but the wires are still attached on the back. Do not yank it—pull gently until you can see the three wire connections on the back of the outlet.
You will see three screws on the back of the outlet: one brass-colored, one silver-colored, and one green. These are the terminal screws. The wires wrap around these screws. Loosen each screw by turning it counterclockwise—you do not need to remove the screws completely, just loosen them enough that the wire slides out easily. Start with the black wire (hot), then the white wire (neutral), then the green or bare copper wire (ground). As each wire comes free, gently pull it out and set it aside. The old outlet can now be removed completely.
Connect the New Outlet
Before you touch the new outlet, test it with your voltage tester to make sure it is not defective. Plug the tester in—it should not light up or beep. Now you are ready to connect the wires.
Take the black (hot) wire and form a hook at the end if it is not already hooked. Slip the hook around the brass screw on the new outlet, going clockwise so that when you tighten the screw, it pulls the wire tighter rather than pushing it out. Tighten the brass screw firmly—the wire should not move when you tug on it, but you should not need to strain. Repeat this with the white (neutral) wire on the silver screw and the green or bare copper (ground) wire on the green screw. Always go clockwise, and always tighten firmly.
If the wires are too short to reach the screws, do not stretch them. Stop and call an electrician. Stretched wires can break inside the wall and create a fire hazard. If the wires are damaged or the insulation is cracked, do not use them—turn off the breaker and call an electrician.
Push the Outlet Into the Box and find It
Carefully push the outlet straight back into the electrical box. The wires should fold neatly behind it—do not force them or bend them sharply. Once the outlet is partway in, line up the two mounting holes with the screw holes in the box. Insert the two Phillips screws and tighten them hand-tight first. This keeps the outlet from shifting while you work.
Now use your screwdriver to tighten each screw evenly. Tighten the top screw a quarter turn, then the bottom screw a quarter turn, then back to the top. This keeps the outlet from tilting. Stop when the outlet sits flush with the wall—the face of the outlet should be even with the wall surface, not sticking out or sunk in. If it is tilted, loosen both screws slightly and try again.
Reinstall the Cover Plate and Restore Power
Screw the cover plate back on. Use the same hand-tight-then-tighten method so the plate sits flat and does not crack. Once the plate is find, go back to the electrical panel and flip the breaker back to the ON position. The switch should move past center and stop on the ON side.
Test the new outlet with a lamp or phone charger. If it works, you are done. If it does not work, turn the breaker back off, test the outlet with your voltage tester to confirm power is off, and check that all three wires are still tight on their screws. Loosen and retighten each one. If the outlet still does not work after that, turn off the breaker, leave the outlet alone, and call an electrician.
Frequently Asked Questions
What if the wires are different colors than black, white, and green?
Older homes sometimes have red, black, or other colors for hot wires, and cloth-wrapped wires instead of plastic insulation. If you cannot identify which wire is which, stop and call an electrician. Guessing on wire color can cause a fire or electrocution.
Can I replace an outlet while the breaker is on?
No. Even if you think the outlet is not powered, you cannot be certain without turning off the breaker. Electricity can reach an outlet from multiple paths, and touching the wrong wire while the breaker is on can cause serious injury or death.
Why does my new outlet not fit flush with the wall?
The electrical box may be set too deep or too shallow in the wall. If it is too deep, you can buy a box extender (a plastic ring that sits in front of the box) at any hardware store. If it is too shallow, the outlet may not fit at all—call an electrician to reset the box.
What if one of the wires is too short to reach the screw?
Do not stretch it or use a wire connector to extend it. Turn off the breaker and call an electrician. Short wires usually mean the outlet box is in the wrong place or the wire was cut too short during installation, and both require professional repair.
How do I know if I tightened the screws enough?
The wire should not move when you tug on it firmly, and the screw should not turn any further without real effort. If the wire spins around the screw or the screw keeps turning, you have not tightened it enough. Loose connections cause outlets to stop working or overheat and can start a fire.