Why might wiring to a socket suddenly die?

[ahlondon]

Had a new kitchen in 2015 with electrics chased into the wall on a ring. A fused 13amp spur (wall switch) turned power on and off to a double socket used by the washing machine and tumble dryer (they were NEVER run at the same time).

Last year the power to the double socket died. It was no longer live (tried changing the socket and checked all connections). No signs of burn or damage. Then checked the fused spur, changing the fuse and again check it all, no signs of burn or damage (I can't recall if I checked it was getting a live feed but would assume it is as it's on a ring and all other sockets are fine including other spurred ones. The cable used to feed the socket is the correct rating. No animal (even a mouse) can get to the cabling to chew it.

What are some of the possible causes of chased/enclosed wiring not supplying current after time?

 

[Jurassicspark]

Further investigation needed.
Sounds like a loose wire somewhere between the circuit.

 

[ETAF]

I can't recall if I checked it was getting a live feed but would assume it is as it's on a ring

DONT assume anything - check with a multimeter/volt meter
The Switch may not work - so as below check that too

The socket that has the SPUR TAKEN from in the kitchen to the FUSED 13A Switch
has that got power and is it on a ring main - in which case 3 wires should be in that socket - maybe check that isnt lose and Live to the SPUR

Take the Switched spur off and look at the wires into the Spur - One set on IN and another on OUT / LOAD , make sure they are connected and LIVE - between LIVE & NEUTRAL on the IN and also between on the LOAD
also check the Switch does actually work - and so when ON if the IN is live the LOAD/OUT is also live when the switch is on / and goes OFF when switched OFF - checking between the L & N for both

If a double pole switch - so Live and Neutral are both switched - CHECK across the LOAD live & Neutral

do you have a mulitmeter / voltage meter , and know how to use it on AC Voltage ?

 

[ahlondon]

DONT assume anything - check with a multimeter/volt meter
The Switch may not work - so as below check that too

The socket that has the SPUR TAKEN from in the kitchen to the FUSED 13A Switch
has that got power and is it on a ring main - in which case 3 wires should be in that socket - maybe check that isnt lose and Live to the SPUR

Take the Switched spur off and look at the wires into the Spur - One set on IN and another on OUT / LOAD , make sure they are connected and LIVE
also check the Switch does actually work - and so when ON if the IN is live the LOAD/OUT is also live when the switch is on / and goes OFF when switched OFF

If a double pole switch - so Live and Neutral are both switched - CHECK across the LOAD live & Neutral

do you have a mulitmeter / voltage meter , and know how to use it on AC Voltage ?

Thanks. When doing the wiring and connection checks I thoroughly checked as far as was possible all cables. I have since bought a voltage detector screwdriver so the most I can test is for live.

While I changed the double socket, I did not change the fused spur and your theory that I should not assume that it was fine is definitely worth exploring! I am optimistic that could solve it A quick google suggests these can fail randomly even with low power usage because of theFCU or other parts.

 

[ETAF]

I have since bought a voltage detector screwdriver so the most I can test is for live.

wont test a problem with the Neutral

switches can fail - had a few do , light switching , and double plug switches , and just a DIYer helping out friends and family

 

[ahlondon]

wont test a problem with the Neutral

switches can fail - had a few do , light switching , and double plug switches , and just a DIYer helping out friends and family

prob not worth buying a multi meter just for that one test

 

[ETAF]

well, they probably are not much more £9.99 from screwfix, 13 in stock at my local branch - so not a special

https://www.screwfix.com/p/lap-dc-digital-multimeter-600v/793RT?gclsrc=aw.ds&gad_source=1&gclid=Cj0KCQjwu-63BhC9ARIsAMMTLXQ2Ly1G0uXgKTo6GWIpkZ70uIF4kt3S_f04iJQpLH028KFjp20zH2saAv-EEALw_wcB&gclsrc=aw.ds

then you can check for continuity as well with the switch all disconnected

and check fuses are not blown

 

[Ragnar_AT]

I‘d probably get the multimeter and start measuring at the load side of the fused connection unit, L - N and L - E. If both checks show something like 230 V, the problem is between the FCU and the socket.

Otherwise I‘d repeat the checks but on the line side. If that gives full voltage, check the fuse and if that‘s good replace the FCU. If there‘s no power into the FCU, check how it’s fed. It‘s most likely on the ring (two wires in each line side terminal) but it could be in the middle of the spur (only one set of wires). In the latter case, try to find out where the supply comes from.

 

[ahlondon]

I‘d probably get the multimeter and start measuring at the load side of the fused connection unit, L - N and L - E. If both checks show something like 230 V, the problem is between the FCU and the socket.

Otherwise I‘d repeat the checks but on the line side. If that gives full voltage, check the fuse and if that‘s good replace the FCU. If there‘s no power into the FCU, check how it’s fed. It‘s most likely on the ring (two wires in each line side terminal) but it could be in the middle of the spur (only one set of wires). In the latter case, try to find out where the supply comes from.

Should I do this before changing the spur?

 

[Ragnar_AT]

Should I do this before changing the spur?

I‘d probably do that first because there might not be anything wrong with the spur unit.

 

[JohnD]

"Suddenly" is the way faults often occur.

Things work until they don't.

 

[FrodoOne]

prob not worth buying a multi meter just for that one test

No one should attempt to do any Electrical; Work without having access to a "cheap", Low Impedance, Voltmeter.