How to Install a GFCI Outlet

1-2 hours

Protect against electrical shocks by installing a GFCI outlet

The National Electrical Code (NEC) requires GFCI outlets in all wet or damp locations such as kitchens, bathrooms, laundry rooms, basements, garages and workshops. This guide will teach you how to safely install a GFCI (ground fault circuit interrupter) outlet.

• GFCIs should be tested monthly to ensure they are providing protection. Press the TEST button, then RESET button. If the indicator light does not go out and come back on, or if the GFCI cannot be reset, it must be replaced.
• Turn off the power before beginning your project.
• Make sure the amp rating of your GFCI matches the amp rating of the wiring and breaker or fuse.
• Always turn off power to a circuit before working on it and place a note on the electrical panel to warn others not to turn it on.
• Wear rubber-soled shoes and use tools with rubber handles.
• Don’t use a GFCI as a receptacle for a refrigerator, freezer or other appliance, as it could trip without your knowledge.

Tip: Take a picture of the wiring on the current outlet before disconnecting the wires in case you need to refer to it later.


Turn off the power
Turn off power- How Install GFCI Outlet

• Turn off power at the circuit breaker or fuse.
• Remove wall plate.
• Use the tester to verify power is shut off.

Remove existing outlet
Remove existing outlet - How Install GFCI Outlet

• Remove mounting screws and gently pull the switch out of the wall box.
• If replacing an existing GFCI, label the black and white wires on the Line and Load terminals.
• Disconnect wires.

Prepare wires
Prepare wires - How Install GFCI Outlet

• Prepare wires by making sure they are straight. Cut if necessary.
• Remove insulation so ¾ inch of the copper conductor is showing.

Identify the line wires
Identify line wires - How Install GFCI Outlet

• Pull wires out of the wall box and position them so they cannot touch each other.
• Restore power and carefully touch the black probe to the metal box or bare copper ground wire. If installing a GFCI on an ungrounded circuit, refer to the manufacturer's instructions.
• Place the red probe to each black wire until the tester lights up. This is the black wire that will connect to the Line brass screw terminal.
• Leave the red probe on the black Line hot wire and place the black probe on each white wire until the tester lights up. This is the white wire that will connect to the Line silver screw terminal.
• Turn power off.

Connect the wires
Connect wires - How Install GFCI Outlet

• Unscrew the terminal screws of the new GFCI until they are difficult to turn.
• Connect the black Line hot wire to the brass screw marked Line by inserting the wire into the back-wire hole and tighten the terminal screw.
• Connect the white Line neutral wire to the silver screw marked Line by inserting the wire into the back-wire hole and tightening the terminal screw.
• If the outlet box has four wires plus a ground, connect the second black wire to the brass terminal marked Load and the second white wire to the silver terminal marked Load.
• Connect the ground wire to the green ground screw by inserting the wire into the back-wire hole and tighten the terminal screw. If there are multiple ground wires, connect them together with a copper pigtail, secure with a wire nut and attach the loose end of the pigtail to the green ground screw.

Place the GFCI into the wall box
Place GFCI wall box - How Install GFCI Outlet

• Carefully bend the wires and push the GFCI into the wall box.
• Tighten the mounting screws to secure the GFCI to the wall box.

Cover with wall plate
Cover with wall plate - How Install GFCI Outlet

• Install the wall plate.
• Restore power and press the Reset button.
• If the GFCI does not reset, the line and load leads may have been reversed during installation. Refer to the “Test Your Work” section of the manufacturer's instruction sheet or call a qualified electrician.