Upgrading a 2 Prong Outlet With a New GFCI

  • 01 of 06

    Upgrade a 2 Prong Outlet to GFCI Outlet

    An ungrounded 2 prong outlet in a bathroom. Home-Cost.com

    This tutorial will walk you through how to improve the electrical safety in your home by easily replacing a 2 prong outlet with a new safe GFCI (or GFI). This safety upgrade should especially be done if the existing 2 prong outlet is near a sink, vanity or tub.

    Needed Tools and Materials

    Continue to 2 of 6 below.
  • 02 of 06

    Turn off Power

    Power panel in an electrical box. Home-Cost.com
    • Turn off power to the circuit feeding the old 2 prong outlet. You do this by going to your electrical service panel and either removing the fuse or turning off the circuit breaker feeding power to the outlet.
    • Go back to the outlet and with a neon circuit tester check to confirm that power has been turned off.
    Continue to 3 of 6 below.
  • 03 of 06

    Remove Old 2 Prong Outlet

    Removing an old two-prong outlet. Home-Cost.com
    • Remove the screw holding outlet cover plate.
    • Remove the two small screws holding the old receptacle to the electrical outlet box. A multi-head screwdriver works great for this.
    • Gently pull out the old 2 prong receptacle being careful not to crack the old wiring.
    • Extend the old receptacle from the box enough to access the black and white wires attached to the old receptacle.
    • Disconnect the old outlet.
    Continue to 4 of 6 below.
  • 04 of 06

    Confirm Space Adequacy for GFI in Outlet Box

    Some old outlet boxes are jam-packed with wires, but most will have enough room for the new GFI.

    • Confirm you have enough room in the box for the new GFI by gently pushing the wires back in the box and test fitting the new GFI.
    • If the GFI didn't fit because there are too many wires in the box, you would have to install a new, larger electrical box that is beyond this Step-By-Step. If it does not fit safely, then replace the old 2 prong outlet.
    • If the GFI fits, then proceed to Step 5.
    Continue to 5 of 6 below.
  • 05 of 06

    Connect Wires to GFI Receptacle

    Connecting wires to a GFI receptacle. Home-Cost.com

    You'll have to determine if the wires you're working with are long enough to connect to the new GFI. If they are not long enough, proceed with this intermediate task:

    Extension Wires

    • Make two extension wires each about 4"-6" long, one white (neutral), one black (hot) and both need to be the same thickness of wire as the wires to which you are connecting. For a 15Amp circuit, you need 14G (14 gauge), and in the unlikely case you're replacing a 20Amp outlet, you'll need 12G (12 gauge) wire. If you don't have any handy, you can usually buy this by the foot from your hardware store.
    • Connect each extension wire to its respective color (black/white) wire with a wire nut.
    • Proceed with the next task.​

    If the wires you're working with are long enough or you have just completed the above intermediate task, proceed as follows:

    • On the back of the GFI receptacle, you'll see four terminals. Two are for "Line," and two are for "Load." In single GFCI installations like this one, we only use the "Line" terminals. The "Load" terminals are only used for multiple outlet installations, not for this repair.
    • Connect the black wire to the brass colored "Line" terminal screw.
    • Connect the white wire to the silver-colored "Line" terminal screw.
    • Gently fold up the wires back in the box and press the GFI into the outlet box.
    • Screw the GFI receptacle to the electrical box to fasten.
    Continue to 6 of 6 below.
  • 06 of 06

    Test GFI and Replace Cover Plate

    Depress RESET button and test for power. Home-Cost.com

    Now we have to test the GFI before we are complete.

    • Turn power to the circuit back on at the service panel.
    • Make sure the RESET button found on the front of the GFI is pushed in and not the TEST button (the TEST button will shut the GFI off).
    • With a neon circuit tester test for power at the GFI.
    • Replace the cover plate. There should also be a little sticker with the GFI that says "No Ground" or something similar. Place that on the GFI to alert people that this outlet is not grounded.

    You have now greatly improved the safety of this electrical outlet by installing the GFI. Even though it is not a grounded outlet, the GFI will protect against shocks.