I've got a very old house, almost 200 years. I'd like to replace the outdated GFCI outlet in my bathroom with a new one. The current outlet is labeled 15A 120V.

I grabbed a new outlet from Home Depot at 15A 125V and wired it up exactly as the original was. After all was said and done, there was no power coming from the outlet, My guess is that there was not enough juice to reset the breaker inside.

I know this is an issue, when i purchased the house and requested GFCI outlets in the kitchen, the change wasn't made because we have a non standard electricity setup and TR outlets were put in instead. I've looked all over but can't find any 15A 120V GFCI outlets anywhere. Am I stuck with this one forever?

  • 1
    Did you press the reset button? Are you sure you wired the incoming wires to the 'LINE' side of your new GFCI?
    – brhans
    Apr 26, 2017 at 17:48
  • What does "nonstandard" mean? Did the "old" GFCI reset? BTW, no 200-yr-old house has original wiring. You might want to see how good the ground and neutral returns are. And further, what was wrong with the old outlet? Don't replace working stuff just because it's not newshiny. Apr 26, 2017 at 18:42

2 Answers 2


120v and 125v outlets are nominally identical. You must have something miswired, or you have a rare faulty unit. Be sure you have power connected to the LINE side. Manufacturers try to make that hard to do by mistake, but you know how us humans are.

  • Good to know. Would the terminals on either side be different for any reason? it could be that i put things in the wrong place, there are 4 wires, two to power the receptacle and then two that go to the bathroom lighting (it's a weird setup, tripping the gfci also turns off the lights)
    – Milo M
    Apr 26, 2017 at 18:12
  • I don't understand your question. Black wires to gold screw, white wires to silver screw, source to LINE, output to LOAD.
    – isherwood
    Apr 26, 2017 at 18:14
  • yup, that's what i did. I'll give it another go. Thanks!
    – Milo M
    Apr 26, 2017 at 18:15
  • Also worth noting bad products get returned and put on the shelf. Always check, and double check the box is not resealed
    – Kris
    Apr 26, 2017 at 23:16
  • If you don't want the GFCI to trip the light, you "pigtail" to the line and don't connect anything to the load. Then the line to the light does not depend on the state of the GFCI. Probably there is no reason to protect the light fixture with a GFCI and if you would trip the GFCI it would be annoying to have the light go out at the same instant. Apr 27, 2017 at 2:05

You know how people say "110V" all the time when they mean household power that is actually 120V? Well, 110, 115, 117.5, 120, 125... All refer to the same thing. This is due to a series of "bumps" the power companies have done over the decades to deliver more total power over the same wires. The next "bump" isn't scheduled, but it will be to 125V and the device manufacturers want to be ready.

You can always fit a GFCI receptacle provided you connect only one hot and one neutral to only the LINE terminals, and nothing to the LOAD terminals.

It can be tempting, if you have another hot+neutral pair coming into the junction box, to connect those to the LOAD terminals. After all, that's how the previous plain outlet was connected, with 2 hots and 2 neutrals connected to it. But there is nothing magical about this on a plain receptacle, those two "hot" screws are simply connected to each other so they are using the receptacle as a splice. There are plenty of other ways to do a splice. And if you want a GFCI to not be entangled in other wiring problems, you can pigtail a short hot and neutral off those splices so the GFCI is a "spur".

If they are telling you that you "can't use GFCIs" that is baloney. What they probably mean (but are unable to communicate) is that your house's wiring has jumbled up neutrals. That is to say, in modern wiring we rigidly keep hots and neutrals with each other, if a hot branches off, a neutral branches off with it, and any neutral serves only its partner hot. In the old days, they would grab any convenient neutral, and so a given hot may return via a different branch's neutral. This breaks GFCIs, which function by comparing current on hot and neutral and tripping on any current unaccounted for.

There's one other reason why promiscuous neutrals are bad. Generally, neutrals don't have circuit breakers. You could plug three different 12-amp heaters into three different circuits served by 3 different hots (so far so good, a 15A circuit can handle 12 amps) except unbeknownst to you, they all return on the same neutral... That neutral will overheat at 36 amps. And it's not on a breaker, so it doesn't trip.

If it was my house, I would slowly root out all the crossed neutrals. But on the meantime I'd get a subpanel, and feed neutral as one of the phases, with multipole breakers so neutral does indeed have a breaker... and move all the legacy circuits over to it. That would be me, I'm a bit nuts.

  • 1
    Another valid reason for not being able to use a GFCI receptacle would be a multiwire branch circuit, which would be pretty common in kitchens. AFAIK they don't make split GFCIs and you need to use a GFCI breaker.
    – Grant
    Apr 27, 2017 at 3:43
  • @Grant no, that's mistaken. You absolutely can use a GFCI receptacle on an MWBC as I instructed (don't use LOAD). That advice will work anywhere a receptacle is now working, remember to splice externally (pigtail). I hear what you are saying, but a shared-neutral topology (including MWBC) is not a reason to not use GFCIs, much the opposite: it's a reason to use more GFCIs, since you will not be able to use the LOAD terminals... And so will need one at every receptacle (or most). Apr 27, 2017 at 13:21
  • but you aren't able to use both legs in one duplex outlet. That is a common setup here in Canada so each individual outlet in the kitchen can draw the full 15 amps. You could replace the box with a double box and two GFCIs, or leave one leg tapped off. But you can't just drop in a GFCI.
    – Grant
    Apr 27, 2017 at 17:25
  • @Grant go double-box if you can, but if not, you can still do it. You tap one hot, on the next receptacle over, you tap the other hot. It's still 2 circuits, but instead of your receptacles being AB/AB/AB/AB you get AA/BB/AA/BB. Not to seem insensitive but I just don't see that as that big of a deal. On the other hand if you're saying each receptacle in a Canadian kitchen has a dedicated 14/3 homerun, different deal, you're correct. However this question seems to be all about GFCIs in imperfect wiring; perfect wiring is always easy! Apr 27, 2017 at 19:15

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