How Electricians Replace a Two-Prong Outlet with a Three-Prong Outlet

person attaching wires to a GFCI outlet on a white tiled wall

Live in an older home with two-prong outlets? You’re probably running out of outlet space for electronics with three-prong plugs.

Here's how an electrician can fix this problem for you!

The Three-Prong Access vs. Affordable Solution Conundrum

There are abundant reasons homeowners shy away from rewiring their homes. Although this option offers the safest solution for three-prong outlet access, it may not be the most feasible one. Rewiring a home is expensive and time-consuming. There are other ways your electrician can upgrade your outlets without rewiring. For example, ungrounded three-prong outlets can be installed; however, there are risks involved with using non-grounded three-prong outlets.

Two-prong outlets have no ground wire, without which the risk of electrocution and appliance damage is substantial. Simply adding an outlet with an additional prong will give you added appliance access, but it will not give you the safety that grounding provides.

Should You Change a Two-Prong to a Three-Prong Outlet with No Ground Wire?

Converting a two-prong outlet to an ungrounded three-prong GFCI protects you from electric shock. However, a ungrounded three-prong GFCI will not provide the necessary ground protection that prevents sensitive electronics from being fried during voltage fluctuations.

Think using a surge protector strip will fix the problem? Unfortunately, those devices are only as good as the outlet they’re connected to. No grounded outlet = no surge protection. Mr. Electric does not recommend installing ungrounded three-prong outlets, but we understand that it can provide a temporary solution for some homeowners.

How Electricians Replace a Two-Prong Outlet with a Three-Prong GFCI

Here’s how professional electricians replace two-prong outlets with three-prong GFCI plugs without running a new ground wire to the electrical panel:

  1. The power to the outlet being replaced is turned off at the service panel. This will be confirmed at the outlet with a multimeter.
  2. The cover plate screw and cover will be removed, along with the two screws holding the old receptacle into the box.
  3. The old outlet will be pulled out, being careful not to crack the old wiring. It will be gently extended to gain access to the wires.
  4. The old outlet will be disconnected.
  5. Some old boxes are tight, so the new GFCI must be test-fitted by gently pushing the wires back and ensuring the new box will fit. If it doesn’t fit, a new, larger electrical box will be used.
  6. If the wires aren’t long enough, a 4-6" extension (“pigtails”) will be added using the appropriate wire for the circuit amperage: 15 amp = 14 gauge; 20 amp = 12 gauge. (DIYers with significant electrical experience attempting this project would have to pick up one white wire and one black wire from a local hardware store, along with the appropriate wire nuts to add the extensions.)
  7. If the wires are long enough, the electrician will look at the terminals on the GFCI and identify the “Line” terminals. These are the only ones that will be used. The wires will be connected:
    • Black wire to the brass “Line” terminal screw.
    • White wire to the silver “Line” terminal screw.
  8. The wires will be gently folded back in the box, pressing in the new outlet.
  9. The box will be screwed-in to fasten.
  10. The outlet will be tested by pushing RESET to turn it on, and then TEST to shut it off. The cover plate will be re-attached and a NO GROUND sticker will be applied.

How to Ground a Two-Prong Outlet

To ensure safety, eventually you’ll want to have grounded outlets. If your home is grounded but some of your outlets are not, bringing in a licensed electrician is the best way to ensure the modifications are completed safely and correctly.

Grounding an outlet requires attaching a wire and running it all the way from your outlet to the grounding screw at the back of your electrical box, which is often a long, complicated endeavor, and exceedingly painful for the inexperienced – sometimes “shockingly” so.

Trust Mr. Electric to Upgrade Your Two-Prong Outlets to Three-Prong

Mr. Electric® is here to help you avoid unnecessary safety risks. Contact us today to upgrade your two-prong outlets to three-prong outlets safely and quickly. You can schedule an appointment online or call us at (844) 866-1367 to connect with your local Mr. Electric.

Alongside your outlets, do you have some cracked drywall that needs repair or replacement? Learn about the expert help that our fellow Neighborly® brand, Mr. Handyman can offer.

This blog is made available by Mr. Electric for educational purposes only to give the reader general information and a general understanding on the specific subject above. The blog should not be used as a substitute for a licensed electrical professional in your state or region. Check with city and state laws before performing any household project.