I am a noob on everything electrical here so really appreciate your input. The location is a 30 yr. old condo with 1 bathroom at southern California.


  • I am replacing the GFCI receptacle in bathroom. Copper wires feed into it.
  • The old receptacle was already there when I moved in. It's a 20 amp receptacle.
  • But the circuit breaker that controls the receptacle is 15 amp.
  • I purchased this Eaton receptacle as replacement.
  • It's a 20A receptacle but the side of the packaging labels it the following.
  • See below for picture of breaker panel. #8 controls the receptacle discussed.

enter image description here

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  1. Did the old receptacle violate building code?

  2. Which amp receptacle would be appropriate here?

  3. Is the label on the package accurate? What does it mean for it to be "15A-125V" AND 20A Feed-Through when it's already a 20A receptacle?

  4. How can I tell if the proper amp breaker is installed?

  • What is the wire size on this circuit? If it is all 12 AWG copper or 10 AWG aluminum, then it is OK to have a 20 A GFCI receptacle. Maybe the current 15 A breaker is wrong. Maybe a 15 A breaker was wrongly installed originally or maybe someone replaced an original 20 A with a 15 A. When was this house built? Does it have copper or aluminum wiring in general and on this circuit in particular? Jul 7, 2021 at 19:07
  • How many bathrooms in the house? If there are two, are the receptacles in them on separate circuits or the same circuit? The code allows (or used to allow) two full bathrooms to be on the same circuit, and that is how all 270 houses in our tract development are wired. Jul 7, 2021 at 19:16
  • What kind of panel do you have? Could you swing open the door and snap a pic of the breakers? Don't remove the front and expose the wiring, just show us the breaker handles. Jul 7, 2021 at 19:30
  • Also could you attach a pic of the front of the existing receptacle (the one you are planning to replace)? Jul 7, 2021 at 20:29
  • @JimStewart Just posted the details. Appreciate your input here. (And where did you get your PhD may I ask?) Jul 8, 2021 at 0:09

3 Answers 3


Well, the labeling on the package isn't correct for a 20A receptacle. It is correct for a 15A receptacle, as they are designed to handle 20A passing through. In fact it is quite normal to install 15A receptacles on 20A circuits. Ignoring the package labeling (likely copy pasted by marketing without talking to engineering) your specific situation is:

  • 15A bathroom circuit
  • New bathroom circuits are supposed to be 20A so... .
  • at some point someone put in a 20A receptacle because "bathrooms are supposed to have 20A", but doing that with a 15A circuit is absolutely wrong!

The good news is that since 15A receptacles (as long as you have at least 2,and a standard duplex counts as 2) are fine on a 20A circuit, install a duplex 15A GFCI and you've covered everything, including upgrading the breaker to 20A if possible. Note, however, that upgrading to. 20A is only possible if all wiring is 12 AWG or larger. It is quite likely some of the wire is 14 AWG, in which case you must stick with a 15A breaker.

  • Thanks! Is it part of code now that bathroom circuits have to be 20A? Jul 7, 2021 at 15:54
  • Yes, it is a requirement. But grandfathered 15A circuits are fine - no need to change, just if you add a new bathroom circuit (kitchen countertop receptacle circuits too) then it needs to be 20A. Jul 7, 2021 at 16:37
  • 1
    And laundry room circuits, and garage circuits. Dedicated, 20A, and GFCI. The garage 20A is really for an EVSE. But if you put in a 50A EVSE circuit, you'll get nice bump in resale value. Buyers want to dream that they might get an EV one day. Jul 7, 2021 at 16:54

Let's review the basic types of receptacle.

enter image description here

We're concerned with the two on the lower left. Note the "T" shaped neutral on the 20A receptacle.

You can't have 20A receps on a 15A circuit!

Code generally requires the receptacle size match the circuit breaker amperage. 15A breaker = 15A receptacles.

THere's an exception that does not help you in any way where 15A receptacles are allowed on 20A circuits. So if the breaker is 20A you don't need the T-neutral. You can use the cheaper "15A" receptacles. As such, all 15A receptacles are UL-listed for 20A pass-thru. UL won't list them if they're not.

So, any receptacle with a T-shaped neutral is banned on 15A circuits. Get rid of it.

Take your time replacing a GFCI

Do it in a 2-step process. Leave the warning tape on the new receptacle - do not remove it yet.

After turning off the circuit, identify the "LINE" terminals on the original GFCI. Note which wires go to "LINE". Being careful to note which is hot (brass screws) and which is neutral (silver screws)... move them (only) to the "LINE" terminals of your new GFCI (and also move the safety ground wires). Plug in a lamp.

Go power up the circuit and make sure the GFCI works. See that the lamp turns on. If you can do it safely without getting nailed (remember, the wires going into a GFCI are not GFCI protected!), try the TEST and RESET buttons.

Once everything checks out, you know this work is correct. Move onto step 2.

If there are any wires on the "LOAD" terminals of the old GFCI, peel off the "For Wizards Only" warning tape, and attach those wires to the LOAD of the new GFCI. This should be trouble-free since the old GFCI did not trip.

If anything goes wrong here, you know the work in step 1 was correct, so you don't need to guess about that.

  • Thank you. But I know how to install the receptacle. I was just confused by the new receptacle packaging and the old 20A receptacle on a 15A circuit. Jul 7, 2021 at 17:10

What is the wire size on this circuit? If it is all 12 AWG copper or 10 AWG aluminum, then it is OK to have a 20 A GFCI receptacle. Maybe the current 15 A breaker is wrong. Maybe a 15 A breaker was wrongly installed originally or maybe someone replaced an original 20 A with a 15 A.

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