Yeah, so the building inspector redflagged a bunch of outlets for not being GFCI. Before I understood how the LOAD terminals work, I just replaced every single one with a GFCI outlet. Most had a second cable for onward power, so I just attached them to the LOAD wires (didn't read the warning tape). Big problem, though.
It's super hard to reset GFCIs, because when one trips, all the upstream GFCIs also trip, and you have to reset them in the right sequence. I also have other circuits with no GFCI protection at all and I'd like to put these redundant GFCI devices to good use.
So how do I identify which GFCIs are useless so I can reclaim them? Let's assume I am now perfectly competent at replacing receptacles.
Best Answer
There's more than one type of GFCI
Aside from the ubiquitous GFCI receptacle, there are also
All of them have "LOAD" terminals. Any load attached to them is in a protected zone that protects the entire downstream circuit (as well as any sockets on the GFCI itself).
GFCI Roundup
Here's how to get rid of that redundant "Yo Dawg" daisy-chaining and get those GFCIs back.
A lot of people install unnecessary GFCIs because the last guy failed to install the sticker. First, they didn't know the outlet was GFCI protected. Second, the sticker actually is mandatory, and that's why the inspector wrote it up. (if you don't want a blue sticker, mark it any way you please; I use white outlet covers and white tape from a P-Touch label maker, and I state the location of the 'reset' also).
Sometimes you need to have multiple GFCIs on the same circuit because you can't protect the downline, e.g. if the last receptacle on the circuit is a refrigerator, radon pump, furnace in the snow belt, or other safety system where a nuisance trip would cause serious problems. In that case, attach all wires to LINE.
In fact, you should never use LOAD at all, unless you actually intend to protect the downstream circuit. Most GFCIs have screw-and-clamp which will allow 2 wires on LINE.
Installation gotchas
If one is giving you problems, stop. Break it into two sub-problems.
Hook up one cable to only the LINE side of the GFCI, turn the breaker back on (I assume you turn off breakers when changing wires) and test it. If the GFCI powers up, tests properly, successfully powers loads etc., then you have the LINE wiring right. Lock it down. and don't disturb it again.
Power off the breaker again and attach LOAD. If doing so breaks it, there is a problem on the LOAD side wiring. Most likely a multi-wire branch circuit, crossed neutral, or imbalanced (hot or neutral in the GFCI protected zone, but not the other). The latter is especially a problem in bathrooms with a plain switch next to a GFCI. Work the problem as best you can; you might have to inspect the next downline circuit. Crossed neutrals or imbalance are genuine defects that endanger your house. Multi-wire branch circuits are safe and legal if done correctly, but are a special snowflake that doesn't play nice with GFCI receptacles.
If you are forced to give up, then attach all wires to LINE and fit another GFCI at the next receptacle. Unfortunately this is one case where you might wind up with a GFCI at every outlet on the circuit; that's par for the course for MWBCs.
Why do you need the sticker?
Think about it. Why did you (or the last person) overinstall the GFCIs in the first place? Because the person who installed the upline GFCI (the one you are keeping) didn't use the stickers. (no one does). Your inspector quite correctly red-tagged the outlet. If the stickers had been used properly in the first place, none of this would have happened.