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Install GFCI Outlets in Bathrooms

I got shocked.

It was over 10 years ago but I still remember the jolting feeling.

If you’ve seen Back to the Future you probably know how Doc Brown got his white hair.

Well, I felt how he looked.

Why is this so dangerous? It’s simple: the human heart has electrical impulses and that rhythm, if interrupted, can be deadly – especially for children.

Certain rooms in your house are required to have GFCI outlets so that you won’t be shocked.

Knowing where they need to be and how to install them can save you a ton of dough. And allow you to sleep a lot better at night.

GFCI Installation Supply List

GFCIs are required by electrical code (I’m talking about the states here) in bathrooms, kitchens, outdoor spaces, and garages.

These are places where moisture creates electrical hazards and you need protection.

Why all this hubbub over an outlet?

Here’s the deal, GFCI’s detect even the tiniest leak in electrical current, and they immediately shut off the power. Simply put: they protect your butt from being electrocuted.

Learning how to wire this kind of outlet is easy and I’ll show you how to do it in 30 to 60 minutes. Plus, you’ll get a ton of great tips that will impress your friends.

Here’s the supply list:

  • Phillips Head Screwdriver
  • Combination Strippers ($10)
  • Lineman’s Pliers ($16)
  • Voltage Detector ($16)
  • 15 Amp GFCI Outlet – Slim Fit and Tamper Resistant ($17.86)
  • GFCI Remodel Electrical Box – PVC and 20 Cubic Inches ($1.96)
  • Wire Nuts ($3)

GFCI Installation Checklist

Here’s what you’ll learn:

  • How to use a voltage detector to safely unwire an outlet
  • How to wire a GFCI with one set of wires in an electrical box (green/bare copper, white, and black)
  • How to wire a GFCI with two sets of wires in an electrical box (green/bare copper, white, and black) and protect downstream outlets from electrical leaks
  • How to properly strip copper wires based on the device you’re using
  • How to pick the correct kind of electrical box for a GFCI
  • How to test a GFCI to see if it’s working

Buying a new GFCI could be the best $17.86 you’ll ever spend because it’ll keep you safe while blow-drying your hair.

Although most of the time I seem to be doing more flat ironing, yes I know how to flat iron hair. It’s a long story. Ask in the comments.

But first, I’d like to take the mystery out of the GFCI wiring process and start with a quick lesson on detecting electricity.

(OKAY, here’s my DISCLAIMER: electrical work is dangerous. Using hand or power tools improperly or ignoring safety precautions can lead to permanent injury or death. Please don’t try to perform any projects you learn here unless you’re certain they’re safe for you. If you’re unsure of something, PLEASE DON’T DO IT. Call a licensed professional. I want you to enjoy DIYing , so keep safety at the top of your priority list!!)

Testing GFCI Power 

Voltage detectors are a must-have for any DIYer.

$16 is way cheaper than a trip to the emergency room. Go to your local home store and buy one.

Use Voltage Detectors

You’ll love voltage detectors if you’re doing any kind of electrical work because the plastic tip will glow (or chirp) when it’s brought into contact with anything that’s energized with electricity.

Place the tip of the voltage detector near an outlet screw terminal, slot, or wire. And if it glows then you know power is still flowing to the outlet.

Always hold the tester so that the insulated portion is in your hand. This ensures electricity won’t flow toward you when testing devices.

Test your old outlet or GFCI with the voltage detector before turning off the power to it. Place the tip of the detector in the outlet’s hot slot.

Test Hot Slot for Electricity

Safely Removing Old GFCI Outlet

Once you confirm there’s power running to the outlet go to your electrical panel and turn off the circuit breaker that supplies electricity to the outlet.

Then double-check the outlet has no power by using your voltage detector.

Place it in the hot slot again.  Then test the neutral and ground slots to make sure the outlet wasn’t wired incorrectly, i.e. someone wired the hot wire to the outlet’s neutral terminal screw.

Believe me, I’ve seen this before!!! It’s pretty easy to forget to wire the black wire to the brass terminal.

Now you can remove the outlet’s cover plate by unscrewing the screws counterclockwise with a screwdriver.

Pull the outlet out from the electrical box by touching the metal tabs on the top.

Remove GFCI by Metal Tabs

DON’T touch the sides of the outlet or the terminal screws!!! Whew, I’m glad you read this. Test the black and white wires with your voltage detector.

If the tip doesn’t glow then it’s okay to unscrew the terminals and remove the wires. But do it in this order:

  1. Black first
  2. White second
  3. Ground last

Installing New GFCI Outlet

Sweet, now you can move on to installing a brand spanking new GFCI.

I decided to get one with an LED nightlight in it. Primarily because I’m getting older and need to use the bathroom at least once during the night.

Everyone in my family has small bladders.

Nightlight GFCI

How to Wire GFCI Outlets 

There are two different wire terminals on a GFCI: Line and Load.

You need to know what these terms mean in order to properly wire this kind of outlet.

Wires that go into the Line terminals are coming from a power source, for example, your circuit breaker.

These are the wires that supply electricity to the GFCI.

Wires that leave the GFCI and provide electricity to another outlet are secured to the Load terminals.

These wires are going to outlets downstream so to speak.

If you only have one set of wires (green/bare copper, white, and black) you’re wiring is easy. Connect the green/bare copper (ground wire) to the green terminal and the black & white wires to the Line terminals.

Add Ground Wires

Make sure the white (neutral wire) goes with the silver terminal screw and the black (hot wire) is partnered with the gold terminal screw. Wire the ground wire first, neutral wire second, and hot wire last.

This configuration means that your GFCI is only protecting itself, i.e. it will be the only outlet that shuts off if there is an electrical leak.

Line Versus Load Wires for GFCIs

If you have two sets of wires (two black, two white, and two green/bare copper) you’ll have to take one extra step versus the above process.

But this is no sweat – it’s easier than changing a toilet paper roll.

The hardest part is determining which set of wires are Line wires. Remember, these are the wires that provide electricity to the GFCI.

Usually, but now always, the Line wires will be the ones on the bottom of the electrical box.

Line and Load Wires

There are two ways to test for the Line wires. You could pull each set of hot (black) and neutral (white) wires from the electrical box.

Make sure they’re sticking out as far as they can go from the box and aren’t touching. Then add wire nuts to the bare copper on all the hot and neutral wires.

Turn the electricity back on at the panel. Then touch your voltage detector to each hot (black) wire. Whichever wire is energized will indicate your Line wires.

The second set of wires will then be your Load wires.

Fining Line and Load Wires

A second, and safer way to test for the Line wires is to attach one set of wires to your GFCI’s Line terminals. You’ll want to attach the bare copper/green wire to the green terminal. Then add the neutral (white) to the silver Line terminal and the hot (black) to the brass Line terminal.

This method will require the second set of wires to be capped with wire nuts: the neutral (white) wire will have a wire nut capping it and the hot (black) wire will have its own nut as well.

Again, you’ll want to turn on the power to the outlet at the panel. If electricity is flowing to the GFCI that means the wires attached to it are the Line wires and the capped wires are the Load wires.

If you don’t have electricity flowing to the GFCI you’ve attached the Load wires to the Line terminals. This isn’t unsafe. You’ll just have to relocate the Load wires to the Load terminals.

Check out my video for the rest of the details on how to install a GFCI. I’ll walk you step-by-step through the wiring process and you’ll see that is pretty darn easy.

Testing Your Wiring: Did You Do It Right?

Before adding the GFCI faceplate you need to test your wiring.

Fortunately, GFCI’s have Reset and Test buttons that help with this process.

Test GFCI Outler

With the GFCI screwed to the electrical box and the power turned on at the panel you can press the Reset button.

It should stay pressed into the GFCI. If it doesn’t you’ll need to check the wiring for mistakes or loose connections or wires touching a metal box.

If your Reset button does stay pressed in the GFCI you should press the Test button with a light plugged into it to double-check the electricity flow. Hitting the Test button should turn off the light.

You’ll have to press the Reset button a second time to make the GFCI energized.

One more thing about GFCIs. They will protect all outlets downstream if they have Load wires attached to Load terminals. This means that if the GFCI trips (the Reset button pops out) the outlets downstream won’t have electricity running to them.

So, you should check for a tripped GFCI if you have an outlet that’s stopped working. And you’ll need to figure out why the GFCI tripped. It could indicate that there’s a short in the outlet that stopped working.

Regardless, it’s a good thing GFCIs were invented – they make modern living a whole lot safer. Don’t forget to test your GFCIs once a month by pressing the Test/Reset buttons.

Follow the specific directions that come with your GFCI and choose one that suits your style or needs.

Choosing GFCI Outlets

Choose a GFCI that is tamper-resistant since the code mandates all outlets be safe for children. Tamper-resistant outlets have slots that are spring-loaded and only work when both the hot & neutral are plugged into at the same time. This prevents any kid who tries to stick a paperclip into the hot slot from being electrocuted.

And lately, I’ve been really liking the outlets that have the nightlights. This is great for kids or grownups who require a potty break in the middle of the night!!

Tamper Resistant GFCIs

LED lights will last for almost 20 years and won’t cause your electrical bill to go up.

As a summary, this is what you should have learned today:

  • How to use a voltage detector to safely unwire an outlet
  • How to wire a GFCI with one set of wires in an electrical box (green/bare copper, white, and black)
  • How to wire a GFCI with two sets of wires in an electrical box (green/bare copper, white, and black) and protect downstream outlets from electrical leaks
  • How to properly strip copper wires based on the device you’re using
  • How to pick the correct kind of electrical box for a GFCI
  • How to test a GFCI to see if it’s working
  • Get a GFCI that is tamper-resistant and possibly has an LED nightlight

What’s Next

GFCI outlets are also required outside – our tutorial has great tips for installing one for holiday lights or anything else.

If you’re doing a bathroom remodel and need help, join one of our online courses – they’ll make your bathroom renovation much easier!

Let me know if you have any questions and I’ll do my best to help.

Thanks as always for reading, watching, and being part of our awesome community.



GFCI Outlet Installation

  1. Carla says:

    I live in an older home where there are a lot of outlets that are just 2 prong. I do have GFCI outlets in the required areas. Apparently I can’t wire an outlet that will take the 3 prongs if the correct wiring is not already there? I spent a lot of money with an electrician to rewire parts of the house to have the GFCIs and the 3 prong outlets put in some areas.

    1. It’s probably a good idea to discuss your options with the electrician Carla.

      Since I can’t be certain with what your setup is I’d trust that he or she can make good decisions on your behalf. But one thing’s for sure, if you have GFCIs installed you’ll be in a safer house 🙂

      1. Good call Jeff. As I recall, it is correct that you absolutely cannot replace a two prong, ungrounded receptacle with a standard three prong one. However, I believe you can do so IF you install GFCI, regardless of if it is a GFCI required location or not. Check with your local electrician, but I believe it is an allowable solution. Sometimes, GFCI’s don’t handle motor loads well, so maybe its not best to fill the entire house with them. John

        1. Thanks John for adding this tip to the discussion. I bet a lot of homeowners still have ungrounded two-prong outlets that aren’t grounded. And replacing some of these outlets with GFCIs would absolutely make sense.

          You’re right about GFCIs sometimes not handling motor loads, I was running a compressor off a GFCI once and it kept tripping. Plugged it into a normal three-prong outlet – no issues 🙂

  2. Asif says:

    Thank you for creating this tutorial, I have always wanted to learn to change outlets and do other minor electrical repairs. I am a real estate agent and I know the GFCI requirements, but i never knew why these were required or what GFCI did. Great work my friend, you’ll have me coming back for more.

    1. Awesome Asif, thanks so much!!

      GFCIs are nifty little devices and they’re super important for all homeowners. So if you can help spot some issues for your clients I’m sure they would be appreciative.

      Plus, letting them know that replacing something like a GFCI isn’t that hard to do would help ease their concern over remodel projects 🙂

      Let me know how I can help you with your homeowners, I’d be happy to lend a hand 😀

  3. Theresa James says:

    This is the kind of outlets that our builder put in my kitchen and all 3 bathrooms. I didn’t understand what they were then, but I have been thankful ever since I understood their importance.

    Thanks, Jeff. It’s a really good thing to point out. So many people build or remodel, that would be the perfect time to take care of this. I’m going to get me one of those little tester things, too!

    1. That’s great Theresa, I’m glad to hear you had GFCIs installed when your house was built. They help me feel better about our girls using hair dryers and other stuff in the bathroom.

      These days, having a GFCI is even more important now that kids are using more and more electronic devices like iPads and iPods.

      I think you’ll like the voltage detector. It’s super easy to use and will come in handy 🙂

  4. Anthony Harper says:

    Hi, I had a huge leak in my bathroom and it actually triggered the gfci and turned off the power after a lot of buzzing. That’s great. It protected us. The thing is that the power never came back on. I turned the breakers off and on with no result. I tried taking off the wires and putting them back on. No result. I seem to remember this happening before and the power coming back after 2 or 3 days, but I’m not sure. BTW, the test and reset buttons push in but do not catch. Any advice on how to get my electricity back on in this bathroom. Will add that “all” other power works fine. It’s just this one bathroom, which is weird as it surely shares q breaker with other outlets. Please advise. Thanks. A.H.

    1. Whew, glad to hear your GFCI worked. That’s good, especially when water is involved.

      It sounds like your GFCI is likely bad at this point. Tried replacing it with a new one BUT make sure to turn the power off to its circuit.

      When you go to the store Anthony by a slim fit GFCI. These kinds of GFCIs aren’t as deep and will fit a bit better into the electrical box. You could also consider adding a GFCI that has a night light. Although I will say the light is a bit bright 🙂

  5. Pink says:

    I replaced a GFCI outlet. Everything worked fine. Until I shoved all the wires back in the box and closed it up. The outlet trips every time. I am assuming something is touching something in a bad way inside the box? Can you tell me what I should look for?

    1. There might be a wire or terminal screw touching the side of the electrical box. If this is the case you could be experiencing a tripped breaker.

      Often the GFCI is too big for the box. You have two options: get a slim fit GFCI or replace the box with a bigger version. I’d try the slim fit GFCI and make sure all the wires are connected securely (but it sounds like you did a good job with the wire connections).

      Let me know your thoughts 🙂

  6. Nicole says:

    Is it normal for a GFCI to feel a little warm. Not hot, just slightly warmer than other outlets or the surrounding wall?

    1. We have the same issue with our GFCIs and even some light switches when they’re on. The best thing to do is call the manufacturer and ask them Nicole. You’ll have to turn off the electricity running to your GFCI, test that it’s off with a voltage detector, remove the cover plate and see who makes the GFCI.

      Chances are it’s Leviton. With the wiring exposed call the technical service number for the manufacturer and ask them if this is normal for your specific GFCI. I bet they’ll help you 😀

      Sorry I couldn’t give you a yes or no. Electrical is one thing I want to be certain about and without being there it’s hard to give a good opinion.

  7. ike says:

    I have a freezer connected to a wall socket that has a GFI in it. we have frequent electrical storms here and the GFI shuts off the freezer. Fortunatly we have been home when it happens so far in time to reset the switch. But we plan to be gone for a day or two.I don’t want to come home to a mess of thawed food. Can I convert back to ta standard receptical.

  8. David A. says:

    I installed two 20 amp gfcis w/ nightlight in the kitchen of my home. They work fine but my problem is the night lights stay on all the time. The sensor isn’t getting enough light to turn off. My question is, will this make my electric bill go up and will this cause them to burn out faster? How long do the night lights last anyway. I have pass and Seymour 20 amp Gfci . Thanks for your help.

  9. Sid says:

    I have a cabin with 100 amp srevice. The plumbing is supplied by a well pump 100 feet from the cabin. The water supply is through a pvc to the cabin. At the cabin, all supply and drain/sewer lines are pvc. There is no metallic plumbing anywhere. Would a gfi outlet work in this case? Is there any need for gfi here?

  10. richard says:

    it made it easy to understand

  11. Sean Wilkison says:

    Hi Jeff,
    Thank you for the awesome tutorial. It was super helpful and a bathroom success. I am still curious of the flat ironing as I didn’t see anyone ask the question? What is the story?
    Thank you,

  12. Norm Garrison says:

    I noticed in the pictures the receptacles stick out from the wall/covers a little bit instead of being flush like we are used to seeing with regular outlets. Is this common, is there a reason for it, or how do you get it flush? Mine, too, sticks out like yours but my wife was concerned about it in the kitchen and thought they should be flush with cover like our regular outlets, but when I install the GFCI they stick out a bit like your pics. There are 3 outlet circuits in our kitchen (I know, normal is 2 but we have a lot of outlets). There were no GFCI in our older home. We are replacing the first outlet in each circuit with a GFCI. Mine are installed over granite with the code required GFCI. Our old ones were all flush. We have one combo box that will have a regular and a GFCI in it…my wife wondered about the one being flush and the other sticking out a little. Also, have read GFCI can get hot even when not being used and to NOT use the outlet insulation sealers that keep out the cold — is that true?

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