GFCI outlet not tripping when tested with the test button

[Venkman]

Electrical outlet #1 is a GFCI duplex outlet. there are 3 additional downstream outlets on the circuit.
When I test the GFCI outlet, using the test button on the outlet, the downstream outlets lose power but the GFCI outlet stays powered.
The outlets are 28 years old.

What is the most likely cause and solution to the GFCI not functioning correctly when tested? I'm thinking that the GFCI has failed internally.

[machinist]

Hi, Venkman. It sounds like your GFCI outlet is likely worn out. Normally, when you press the test button, it should shut off power to both itself and any downstream outlets on the same circuit. Since your GFCI isn’t losing power (only the downstream outlets are), it’s probably failed internally—especially given that it’s 28 years old.

A new GFCI should restore full function. Once it’s swapped out, test it again to make sure both the GFCI and the downstream outlets lose power when you press the test button. In rare cases, incorrect wiring can also cause unusual GFCI behavior. When installing the new GFCI, double-check that the wiring is securely connected to the correct terminals (the "line" and "load" sides). This ensures it’s wired to protect both itself and the downstream outlets.

A new outlet should fix the issue, and a quick check on the wiring will ensure everything’s set up safely and correctly!

[Venkman]

Just came back to give feedback on the cause of the problem. The GFCI receptacle was incorrectly wired. The electrician that wired the house connected the line wires to the load terminals and vice versa. It's been this way since 1996 The only way I found out is that I unplugged an extension cord and tripped the GFCI, killing the downstream receptacles but not the GFCI one.

I'm surprised that an experienced, licensed electrician would not test his work to ensure everything was correct. I can understand making a mistake but as old Ronald Reagan was fond of saying "trust but verify".

I corrected the wiring and everything is hunky dory.

Thanks to you machinst for your answer.

[machinist]

Anytime! Really happy to hear you got it all sorted.

It’s surprising that an experienced electrician missed that mix-up with the line and load wiring—it’s easy to see how it could happen, but a double-check would’ve caught it. Glad you trusted your instincts and got everything working just right!

[Venkman]

I was surprised too of course. But this is the same electrician that mounted the house CB panel 5 feet out from the corner of the basement just because the plumber beat him to the wall that the service line from the street came in on, with the waste pipe to the septic system. Rather than go to the general contractor to resolve it, he just nailed 2x4s to the concrete floor and mounted the box 5 feet from any wall, in the middle of nowhere. I should have expected more hinky stuff.
I've had shorts in switches in the house because over the years the plastic around the back stabbed wires on the residential quality switches cracked, allowing the wires to wiggle and short out.

[machinist]

But this is the same electrician that mounted the house CB panel 5 feet out from the corner of the basement

Wow, sounds like you've had quite the adventure with that electrician’s work. Mounting the breaker panel five feet out from the wall—who does that?

Always good to share these kinds of stories because it’s nice to know we’re not alone in dealing with the "creative" work some contractors leave behind. If you ever need a second pair of eyes or advice on resolving these quirks, this forum's a great place to troubleshoot or brainstorm solutions.