GFCI Outlet Installation & How to Do it in 4 Easy Steps

GFCI – (Ground Fault Circuit Interrupter)

I didn’t prepare this GFCI outlet installation guide for conditions where everything is perfect and nothing can go wrong, that’s why it is a little longer than others. So don’t start your project without reading description of items 1-4, it’s extremely important for your safety. Good luck on your GFCI outlet installation project!


  1. Disconnect power supply to the electrical outlet you are planning to remove and install GFCI receptacle in its place. The safest method is to turn off the main breaker in the electrical panel or remove the main fuse
  2. Remove wires from an old electrical outlet
  3. Correctly install wires on the new GFCI receptacle terminals
  4. Secure the new GFCI receptacle in place, install GFCI receptacle cover plate and test installation


Easy, isn’t it… and safe if you follow the steps below.

The minimum required tools for this 4 step GFCI outlet installation are:


  • The table lamp – for testing (or some other devices like those on my picture)
  • The screwdriver (flat and Philips recommended)
  • Electrical tape – to insulate GFCI receptacle terminals
  • Electrical pliers and wire strippers – this might not be necessary, but in some cases it will make this GFCI installation much easier
  • Wire nuts and 6″ of #14 or #12 copper wire – if some slightly more advanced testing or installation is necessary


1. This is the most important part of the GFCI receptacle installation process – you have to make sure that the wires you’re installing receptacle on HAVE NO POWER!

The best way would be to turn off the main breaker or pull out the main fuse in the electrical panel. By doing this you wouldn’t have to worry about testing and figuring out unmarked circuits. If you have plenty of daylight or a good flashlight / another source of light for this project – this is the safest, easiest, and the fastest way to go.

Before turning off the breakers or removing fuses and starting GFCI outlet installation – manually turn off electronic devices (computers, video game consoles, etc.) – they might be sensitive to an abrupt power loss.

Also, if you have a burglar alarm or any other device that requires constant power supply or it will otherwise notify your provider, make a phone call and let them know that your power will be out for a few minutes (that is how long it usually takes to install a GFCI receptacle).

Even if your electrical panel has a fuse or circuit breaker, pointing (labeled) directly to the spot that the new GFCI outlet installation is going to take place, check that circuit with some type of a testing device or a table lamp after the breaker (or fuse) have been turned off / removed.

There are a few reasons for this double-checking:


  1. Since the time of electrical panel original installation or labeling, there could be some changes / remodeling performed, and description inside the panel is no longer pointing out to the same spot. By turning the breaker off or removing the fuse, you might be disconnecting power from something other than the outlet you’re assuming it is protected by this fuse / breaker. Double check it, triple check it, because installing GFCI outlet on hot wires might hurt or even kill you.
  2. Always test for power in both sockets of your existing outlet. There might be a separate power supply for each side of your receptacle. Small tabs between the wire terminals on both sides of the receptacle are sometimes removed and two separate sets of wires from two breakers / fuses connected on each side.


You cannot install GFCI receptacle in such configuration – don’t even try! You have either to eliminate one of the circuits or install two separate GFCI receptacles – get a licensed electrician for that.

If your testing device plugged into the power outlet shows no activity with the breaker / fuse in either “on” or “off” position there might be a broken wire at the receptacle terminal, faulty outlet itself or many other reasons. In such case, to make sure that there’s no power in the wiring supplying this receptacle (since you can’t test it without removing it from the box), I would advise you to turn of the main breaker / pull the main fuse or call an electrician (if you have previously decided otherwise).


  • After you’re 100% sure that the power is OFF, GFCI outlet installation itself becomes quick and easy… almost always.


#2. GFCI receptacle installation – removing wires from an old outlet


  • Unscrew the outlet cover plate
  • Unscrew the receptacle and carefully pull it out from the box


Because electrical box plate edges might be sharp and damage the wire insulation instalator (while you pulling it out) this is extremely important when dealing with old, cloth & rubber-insulated wiring. This old insulation will sometimes disintegrate while you’re working on your outlet – if you notice cracks / gaps in insulating material, call the electrician, don’t force those bare wires back into the box!

Also, if instead of a copper you’ll notice an aluminum wire connected to the electrical outlet… it’s a whole different story, call a qualified electrician / don’t install GFCI receptacle on an aluminum wire – it’s a safety hazard, and such installations are not permitted.


  • If you only have 2 wires (not counting the ground wire – green, bare or other color marked with a green tape / connected to the green screw) attached to the receptacle (one should be white or light gray plus a second color), those are called LINE wires – remove them from the receptacle and proceed to the next #3 step of the GFCI receptacle installation.
  • If you have 3 wires – white and two color (plus ground), and open tab(s) between the receptacle hot terminals (between color wires), there’s either 2 separate circuits (explained earlier), or half of the outlet may be controlled by the switch. You can eliminate switching by capping the switch leg (color wire from the switch) with a wire nut (make it tight and use some electrical tape so it doesn’t fall off the wire) or cap the other wire if you need to have a GFCI controlled by the switch.
  • If you have 4 wires (plus ground), and closed tabs between the receptacle terminals, one pair of wires is a LINE (main power supply) and second is called LOAD (feeds power to other receptacle). To determine which one is LOAD and LINE – you must know this to properly install GFCI receptacle (use this also to identify switched / constant power wires location) – follow those steps

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