Odd electrical issue with socket

[thecrow]

Wondering if anyone can shed any light on this. Redecorating a spare bedroom and in the process needed to convert a single socket to a double. Cut out and fitted the new back box and stuck the old socket back on until painting was done. All done.

I noticed that my circuit tester was quietly buzzing (probably 30% of the volume when using it normally) and displaying one red light while the socket is switched off, but only when the kettle is boiling on the socket directly below in the kitchen. As soon as the kettle finishes the tester goes off.

It also does it in the socket where the kettle is plugged in, but doesn’t do it in any other nearby sockets, nor if the kettle is moved to any other socket.

Any ideas what it could be? Induction maybe? Wiring is back in the socket the same. Unfortunately I didn’t think to test it before I did anything so it could have always been like this, but no idea if I should be concerned or not!

Socket in question:



Thanks.

[No ideas for a name]

The tester apears to say you have swapped line and neutral.
I would be looking at that first.

Then test ring continuity... But only if you are confident you know what you are doing.

Edited by No ideas for a name on Friday 6th December 10:09

[tux850]

No ideas for a name said:

The tester apears to say you have swapped line and neutral.
I would be looking at that first.

I would expect two lights to illuminate with these types of testers in that scenario - one as a result of the unexpected potential difference between the 'hot neutral' and earth, and a second due to the potential difference between the live and neutrals (which still exists even if swapped).

A single light, with the socket switched off, is likely down to capacitive coupling on the neutral. This would also explain a feeble buzzer output too, and would correlate with the kettle situation if its wiring is run in close proximity.

The bottom line, though, is that the socket needs testing properly if in any doubt. A plug-in tester is a just a quick-and-dirty test tool that doesn't mean much beyond the most basic of connectivity test.

[thecrow]

tux850 said:

I would expect two lights to illuminate with these types of testers in that scenario - one as a result of the unexpected potential difference between the 'hot neutral' and earth, and a second due to the potential difference between the live and neutrals (which still exists even if swapped).

A single light, with the socket switched off, is likely down to capacitive coupling on the neutral. This would also explain a feeble buzzer output too, and would correlate with the kettle situation if its wiring is run in close proximity.

The bottom line, though, is that the socket needs testing properly if in any doubt. A plug-in tester is a just a quick-and-dirty test tool that doesn't mean much beyond the most basic of connectivity test.

Yes that all makes sense to me. I’ve no ability to test beyond plugging in that tester though, and while it’s probably always been like this I can’t now in good conscience leave it so will get an electrician to check it properly. Thanks for the info.