Commercial & Residential Electricians in Mesa AZ.


How To Replace A GFCI Outlet

Need to replace GFCI outlets? You can consult with our in-office electrician in Mesa AZ free of charge. Voted best electrician Mesa AZ, he will answer all of your GFCI outlet replacement questions and provide you with the information that you are looking for. Our local Mesa AZ electricians are available for you to consult with about replacing GFCI outlets Monday thru Friday, from 8:00 AM until 5:00 PM. Give them a call today; you will be happy you did!

How To Replace An Old GFCI Outlet With A New One Step By Step

How to replace your GFCI outlet
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Tools Needed:

  • Slotted screwdriver
  • Wire cutters
  • Voltage tester
  • Flashlight

Materials Needed:

  • GFCI outlet
  • Masking tape
  • Sharpie marker (fine point)

Step 1: Turn The Electricity Off

Turn off the circuit breaker to aviod electrical injury

At your circuit breaker box turn off the circuit breaker that supplies power to the GFCI outlet.

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Do not trust the labels inside your circuit breaker box, they can be mislabeled and cause you to turn off the wrong circuit. If you are not absolutely certain which circuit breaker shuts off the power to the GFCI outlet it is best to turn off the all of the circuit breakers, including the main circuit breaker. This will ensure that the power is off and remove the possibility of electrical injury.

Step 2: Remove The Old GFCI Outlet From The Box

  1. Unscrew and remove the cover plate.
  2. Remove the mounting screws that are attaching the GFCI outlet to the electrical box.
  3. Carefully pull the GFCI outlet out of the electrical box, the power may still be on. We still need to confirm that the electricity has been shut off.

Step 3: With Your Voltage Tester, Confirm That The Power Going To The GFCI Outlet Is Off

  1. Place one probe on the upper brass screw and touch the other probe to each one of the two silver screws and the ground screw.
  2. Repeat this, but this time touch one probe to the lower brass screw and touch the other probe to each silver screw and the ground screw again.
  • If any voltage is detected repeat step #1 and then step #3 again.
  • If no voltage is detected, the power is confirmed off and you can safely proceed with the following GFCI outlet replacement steps.
How to check for electrical power on the terminal screws before working on your GFCI outlet
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  • Do not insert the probes into the slots on the front of the GFCI outlet to confirm that the power is off. You are replacing the GFCI outlet because it is not working properly. A false reading of being “off” could be delivered while the attached wires are still fully energized.
  • Some of the original GFCI outlets were made with wire leads that connected to the structural wiring with wire nuts. If you are changing out one of these older GFCI outlets it’s best to carefully label each wire as described in step #4 first and then undo the wire nuts and confirm the power is off. If you need additional help getting these older GFCI outlets changed, contact our local electricians in Mesa.

Step 4: Label The Wires Before Disconnecting Them From The Outlet

  1. Take your masking tape and cut a 3 to 4 inch piece. At the center of the masking tape, fold it over the wire (a few inches away from the outlet) so the sticky sides come together making a tag.
  2. With your marker, identify each wire (examples include: line hot, line white, load hot and load white). Ground will always be either a bare wire or colored green so there is no need to further identify it.
Label each wire attached to the GFCI outlet line or load
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The back of the existing GFCI outlet will have markings on the top and bottom called “line” and “load”. The left and right sides will be further identified as “hot wire” (brass screws) and “white wire” (silver screws). Some outlets will have just one black, one white and one ground wire attached and others will have more. It is imperative that all of the wires are identified and marked before detaching them so they can be properly reattached to the correct terminals of the new GFCI outlet.

Step 5: Unfasten And Prepare The Wires To Be Connected To The New GFCI Outlet

  1. Now that each wire is clearly identified, loosen the screws and detach all wires from the outlet.
  2. Inspect the ends of each wire and cut off any damaged ends and strip off insulation as needed.
  3. Before preparing the wires you will need to determine what method of attaching the wires the GFCI outlet allows. Most modern GFCI outlets have back wire clamps that allow the wires to be straightened and inserted into the clamp holes and tightened down with the screws. Other GFCI outlets will require the wire ends to be bent into a hook shape and wrapped around the screws.

Note: If you are wrapping your wires around the screws make sure that the open end of the hook is going in the tightening or clockwise direction of the screw. This will cause the hook on the wire to close when the screw gets tightened making a better connection.

How to attach the wires to a GFIC outlet
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If your home was built before 1974 you may discover that aluminum wiring was used instead of copper. If you find aluminum wires you will need to splice a piece of copper wire to each aluminum wire using Ideal No. 65 wire nuts. They are a distinctive purple color and are the only UL approved wire nuts for splicing aluminum wires to copper wires. For more information visit our aluminum wiring repair page. Once you have made these splices you can prepare the copper wires as described above.

Step 6: Put The Ground Wire On The New Outlet

Replacing a GFCI outlet diagram

The ground wire gets attached to the green or grounding screw.

  • Note A: The ground wire will always be either green in color or bare.
  • Note B: The ground wire is the single most important wire in any electrical system. If you do not have a ground wire present in your electrical wiring, we strongly suggest that you read our pages about grounding and whole house surge protection.
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If you have a home with old electrical wiring there is a possibility that you will discover that the ground wire is missing. This was not a mistake that was made when your home was first built. It is because prior to 1962 the national electrical code did not require an equipment grounding conductor or ground wire for all receptacles. To make your installation code compliant you must either mark the GFCI outlet with the words “No Equipment Ground” or add a ground wire. This information is found in section 210-7(d)(3) of the national electrical code.

Step 7: Put The White (Neutral) Wire Or Wires On The Outlet

  • Attach the wire or wires marked “line white” to the line side silver screw of the outlet.
  • Attach the wire or wires marked “load white” to the load side silver screw of the outlet.

Step 8: Put The Hot Wire Or Wires On The Outlet

  • Attach the wire or wires marked “line hot” to the line side brass screw of the outlet.
  • Attach the wire or wires marked “load hot” to the load side brass screw of the outlet.

Step 9: Fold The Wires Into The Electrical Box And Push The Changed Out Replacement Outlet In

  1. It is best to start with the ground wire because we want it to be in the back of the electrical box to reduce any accidental short circuiting contact with the wiring terminal screws on the new outlet.
  2. Fold in the remaining white and hot wires. Try to keep them on their respective sides of the box especially if you are working on an older electrical system. Many older electrical systems will have very shallow outlet boxes. This will prevent crossing the wires behind the receptacle and leave you more space for the GFCI outlet to fit into the box.
  3. Push the outlet all the way into the box and make sure it is straight and level. Do not attempt to tighten down the mounting screws if the device is twisted (not seated in a flush like position), you will bend the mounting brackets on the device. Sometimes you will need to put the device in and out more than once (adjusting the bent wires) to get it to settle in the box without being twisted. Once the device is positioned straight and level you can tighten down the mounting screws.
  4. Reinstall the cover plate.
Fold the wires and put the replacement GFCI outlet into the outlet box
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When installing the cover plate always leave the screws with the slots in a vertical (up and down) position. This is especially important when the device is located outside, in a bathroom or in other damp locations because we want any moisture to run through the screw slots instead of collecting on the slots. Doing this will greatly reduce the chances of the screw heads rusting over time. It also looks much more professional when all the screws are aligned in the same direction.

Step 10: Turn The Electricity Back On And You're Done Replacing Your GFCI Outlet

  1. Turn all of your circuit breakers back on. Your new GFCI outlet should now be energized but it will not be operational until the reset button is pushed.
  2. Activate the outlet by pressing the reset button.
  3. Test the outlet by pushing the test button, this should trip the device confirming that it is working properly.
  4. Push the reset button again and enjoy your new GFCI outlet.

Troubleshoot Problems

Make sure the replaced outlet is working by pressing the test and reset buttons

The Reset Button Will Not Reset:

  • Make sure each wire has been labeled and terminated correctly, the device will not reset if it is not wired correctly.
  • Inspect the load side wires for damage and repair if needed.
  • Make sure the ground wire is not touching the terminal screws.
  • Unplug everything that is plugged into other outlets protected by the GFCI outlet you just replaced. The outlet may be working properly and it is responding to a problem with a defective piece of equipment plugged into the protected circuit.
  • For more information visit our GFCI outlet won’t reset page.

The Circuit Breaker Trips Or Will Not Reset:

  • Make sure the wire has not been damaged during the installation.
  • Check to make sure the ground wire is not touching the hot terminal screws.
  • Make sure each wire is connected to the correct screw.
  • For more information visit our breaker keeps tripping page.

For more help with how to change a GFCI outlet and answers to all of your electrical questions, consult with our local Mesa electricians free of charge. Voted best electricians Mesa AZ, they are available Monday thru Friday, from 8:00 AM until 5:00. They will give you the professional information that you are looking for. Free estimates are also available. Call today; you will be happy you did!