How to Install Ground Fault Circuit Interrupter Outlets

By
Timothy Thiele
Timothy Thiele

Timothy Thiele has an associate degree in electronics and is an IBEW Local #176 Union Electrician with over 30 years of experience in residential, commercial, and industrial wiring.

Learn more about The Spruce's Editorial Process
Updated on 08/25/22
Reviewed by
Larry Campbell
Larry Campbell
Reviewed by Larry Campbell

Larry Campbell is an electrical contractor with 36 years of experience in residential and light commercial electrical wiring. He worked as an electronic technician and later an engineer for the IBM Corp. is a member of The Spruce Home Improvement Review Board.

Learn more about The Spruce's Review Board
An outlet half-way through installation

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Project Overview
  • Working Time: 15 - 30 mins
  • Total Time: 15 - 30 mins
  • Skill Level: Intermediate
  • Estimated Cost: $15

Ground fault circuit interrupter (GFCI) outlets are special electrical receptacles that have built-in mechanisms to cut power if the outlet senses an electrical imbalance or surge, such as one that would happen if a person was getting electrocuted. Unlike a GFCI breaker, GFCI outlets respond in milliseconds to ensure that the power is cut before an electrical current would have the chance to travel through someone's body and reach the heart.

Building codes require that GFCI outlets be installed in any wet location where the combination of water and electricity could prove to be problematic. This includes kitchens, bathrooms, areas around pools, wet bars, and unfinished basements and attics, garages, outdoor outlets, and moist crawl spaces. The outlets can be installed anywhere, however, providing an extra degree of electrical safety to your home.

When a GFCI outlet is no longer functional, it should be replaced. This is a simple enough task for any homeowner to accomplish, but you must follow all safety protocols detailed below. If you are not comfortable working with electrical wiring, you should call a professional electrician.

Warning

You must be sure that the power to the outlet you are replacing is turned off before beginning. If not, you risk electrical shock, which can have serious consequences.

What You'll Need

Equipment / Tools

  • Flat-head screwdriver
  • Phillips-head screwdriver
  • Circuit tester
  • Pen or pencil

Materials

  • Tape

Instructions

  1. Turn Off the Power

    Before you begin any electrical project, go to the electrical panel and shut off the circuit that you’ll be working on. Sometimes, not always, the electrician who installed your service will mark the panel, on the inside of the door with the location that each individual breaker supplies. If it is marked, turn off the correct circuit. If it is not marked, then you'll need to turn off the main breaker, found at the top of the electrical panel. This will cut all electrical service to your house, so ensure all electrical appliances can go without power for about 15-30 minutes before throwing the breaker.

  2. Check the Circuit

    Always double-check the circuit with a tester or meter to be safe. Never assume that, just because you've thrown what you think is the right breaker, the circuit is off.

  3. Remove the Outlet and Mark Each Wire

    Now that the outlet is safe to work on, you must remove the existing outlet cover and then the outlet. The outlet cover usually has one screw in the middle holding it to the outlet. If it is a decorative type or a GFCI already in the location you are replacing, it will have two cover screws, one at the top and one at the bottom. The outlet itself generally has a screw at the top and the bottom holding it to the electrical box that's mounted inside the wall.

    After all the screws are removed, gently pull the outlet out of the wall so that the wires are visible.

    Do yourself a favor and get a pencil and paper so that you can mark down how everything is connected. If you have a roll of masking tape, mark down things like “right top side hot wire,” and you’ll be able to place these right on the wires themselves. Use the tape and label each wire, paying close attention to what color screws each connect to. This will eliminate any guesswork when installing the new device.

    Tip

    In addition to marking the wires, you can also take a photo of the wiring using your smartphone to make it easier to put in the new outlet in exactly the same way the old one was installed.

    Once you've documented the way the wires are connected, remove the screws holding them to the outlet and dispose of it.

  4. Reattach the Wires

    To install the new outlet, attach the wires as indicated by your tape tags or photo.

    For additional guidance, you'll attach the "hot" wire to the brass terminal. This is usually the black or red wire. Next, connect the white wire to the silver screw. This is a neutral connection. The bare or green wire is the ground connection. Place it around the green screw.

    When you have connected all the wires successfully, give the entire side of the outlet a wrap of electrical tape. This will eliminate any screws from touching either the side of the box or a stray wire when reinstalling.

  5. Install the Outlet

    Press the outlet back into the electrical box before fastening it with the screws provided. You may have to carefully push and bend the wires back into the box to make everything fit. Now install the cover plate that came with the outlet, and your installation is complete.

  6. Turn on the Power and Test

    Once you’re satisfied, go back to the electrical panel and turn on either the circuit breaker you turned off earlier or the main breaker, if that's what you used. Go to the new GFCI outlet and press the reset button. Now use your tester to check the circuit. You can also use a lamp or any small appliance to see if power is restored.

When to Call a Professional

If your new outlet fails to work after you've followed the instructions above, or if you find that the "reset" button on the outlet is frequently popping out, it's time to call a professional electrician to evaluate the situation.

How Often to Test GFCI Outlets

Experts recommend testing your GFCI outlets about once every three months. You can use the official start of each season to help remind you to accomplish this task. To test the outlet, simply press the "test" button. When you do so, the "reset" button shop pop out loudly. If it doesn't, you'll want to replace the outlet. If it does, then your outlet is in good working order and you should simply press the "reset" button until it catches and stays put, hopefully until the next quarterly check.