Faulty Double Socket

999MSE

I have a faulty switched double socket. Something plugged into one of the sockets stopped working recently and trial and error revealed each socket worked if the other was switched off but if both were on, only one socket worked. I stopped using the socket.

Today I swapped the face plate, wiring seemed ok (old but ok and all firmly connected correctly to the old faceplate). Having replaced the faceplate the issue remains the same.  I went and purchased a cheap socket tester.  All the other sockets downstairs report 'correct' when tested, the rogue one reports 'No Neutral'.  I'm sure the neutral wire is connected correctly to the new faceplate (and was also firmly connected to the old faceplate).

I will obviously not use the socket and next step is probably to get a sparky to investigate but thought I'd ask here first. I'm struggling to understand how the faulty behaviour is explained? Now the 'no Neutral' report may well be wrong given it is just a cheap tester - I take it to just mean 'something is wrong' but what?

House is old and has not been rewired for at least 30 years, probably much longer. The particular socket in question only has one set of wires, so I believe this means it's a spur, could this mean there is a fault with the wiring from the ring or a junction box perhaps?

Almost certainly not going to make any further attempts to fix this myself but hoping to understand how serious or straightforward this could be.

Thanks
999

grumpy_codger

999MSE said:

... trial and error revealed each socket worked if the other was switched off but if both were on, only one socket worked.

...

Having replaced the faceplate the issue remains the same.

IMO, this is a very odd fault. I can't come up with any explanation.

Grenage

It could be a dodgy connection from wherever it spurs from.  Likely the nearest socket or a junction box under the floor.  I would personally check those connections if I felt confident, then get a sparky if no joy.

If you don't feel confident, just get a sparky.

Keep_pedalling

Is this socket on the main ring or a spur?

Section62

Keep_pedalling said:

Is this socket on the main ring or a spur?

With "only has one set of wires" it would be hoped it was a spur or radial circuit.... but it needs looking at by a qualified electrician to find out exactly what is going on.

Ectophile

If it's only got one live, one neutral and one earth, then it's probably a spur.

If that's the case, the problem could be wherever the wire to that circuit was spurred off from.  Maybe a loose neutral wire.

Risteard

Sounds like there is a missing neutral, which is becoming apparent under load. Get an Electrician in.

999MSE

Thanks for all the replies everyone. Next step will be to get a professional in.