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How To Install a GFI Outlet

GFI outlets are an NEC approved type of electrical outlet that is required in potentially wet areas in homes like bathrooms and kitchens.

GFI stands for Ground Fault Interrupter and is an electrical outlet with a built-in circuit breaker. Basically, the GFI outlet trips when it senses a difference in current flow above a certain set point. The outlet can be reset by pushing the reset button but the reason the outlet tripped should be discovered and fixed first. The purpose of the GFI outlet is to protect you from electrocution. According to OSHA, you may experience a brief minor electrical shock before the outlet trips, however. Installing a GFI outlet or receptacle is not difficult as long as you carefully follow the directions.

Removal of the old electrical outlet

GFI outlets are for your protection

GFI outlets are for your protection

  1. Turn off the power to the circuit you will be working on. Either flip the appropriate circuit breaker in your electrical panel, or unscrew and remove the appropriate fuse.
  2. If you do not know which circuit breaker or fuse controls the circuit you will be working on, you can find out by plugging in an electrical appliance like a hair dryer and turning it on. Then, turn off each circuit breaker in your electrical panel one by one until you find the one that turns off the hair dryer. Leave it off, mark it, and seal it with a piece of tape that says, “Leave off!”
  3. Do not work on the old outlet until you have tested it with a circuit tester or multi-meter to verify that the power to it is, indeed, off.
  4. Unscrew and remove the outlet cover plate.
  5. Remove the two screws that hold the old outlet in the outlet receptacle box.
  6. Pull the old outlet out of the box, straightening the wires connected to it as you go.
  7. If there are only three wires connected to the outlet, it is located at the end of a series of outlets and lights.
  8. If there are four or more wires connected to it, it is located in the middle of a series circuit.
  9. Unscrew the terminal screws and remove the wires.

Install the new GFI outlet

  1. Determine which wires come from the electrical panel. Separate the wires in the outlet receptacle box and secure the room the outlet is located in by posting a friend or family member to watch that no one enters. Turn on the circuit breaker at the electrical panel. Using a circuit tester or multi-meter, test the exposed wires to determine which ones are live. Mark them and turn the power back off.
  2. Connect the wires from the electrical panel to the terminals on the GFI outlet marked “Line”. Connect the remaining wires to the terminals marked “Load”.
  3. Insulate the wire connections by wrapping the terminals in a layer of electrical tape.
  4. Make sure you connect the ground wire to the proper terminal usually marked green.
  5. Push the GFI outlet into the receptacle box and install both screws that secure the outlet to the box.
  6. Install the outlet cover plate.
  7. Turn on the power at the electrical panel.
  8. Test the outlet. Push the “test” button and you should hear an audible click. Plug an appliance like a hair dryer into the outlet. It should not work.
  9. Press the reset button to restore power to the outlet.


If there were four or more wires going to the old outlet, the GFI is installed in the middle of a series circuit. After installing the GFI outlet, test each remaining outlet that you suspect is on the same circuit to make sure that each one has power. Do not forget to check lights, as well, because lights can be on an outlet circuit.

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