How do I change a two way switch to a one way??

[txacoli]

I have just redecorated a bedroom in the house and discovered that the light switch - which has never worked since I moved in 6 weeks ago - used to be a two way switch. The previous tenant has (presumably, because I can't see it) cut the wire to the second switch, blocked it and cemented it into the wall. When I took the wallpaper off, I can see where he appears to have done this.

Now, I have just one two-way switch which doesn't work. Can I change this to a single switch and if so, how? Or, is there something I can do to this switch to make it work?

When I took the plate off the wall to look at the wires, there are two lots of red, blue and yellow wires, plus one large green wire (earth) wired to the metal casing. I desperately want to get the light working and while I'm sure it's easy enough, I want to make sure I get it right. Can anyone help please?

 

[hairyben]

Two lots of red, yellow and and blue wires? Thats odd. Not one lot of Red/yell/blue and one red & black?

Might help if you post some up close pics of the switch showing how it's terminated.

 

[sealeon]

could of been an intermediate maybe

 

[hairyben]

could of been an intermediate maybe

Pondered that... but wanted to eliminate the simple first!

 

[txacoli]

Hi Guys

First of all, I've uploaded an image to give more clarity to the situation.

Untitled

• txacoli
• 7 Nov 2008
• 1

Secondly, I've given you wrong information - there are more wires in the light fitting than I have ever seen in one before (but then, I've never fitted a two-way before) and here is how they are wired.............

TOP ROW (as you look at the picture)
Left = L1 - Yellow wire
Centre = L2 - Blue wire
Right = Common - Red wire

BOTTOM ROW (as you look at the picture)
Left = AC only, 5 Amp x, 250v, Common - Red wire
Centre = L1 - Blue & black wires
Right = L2 - Yellow & red wires

+ Green earth wire

Hope this helps more. I think the picture is clear - you should certainly be able to trace the route of the wires on it.

 

[ban-all-sheds]

The previous tenant

Shame you started decorating etc.

Getting the switch working was without doubt the landlord's responsibility, and if you'd complained on day 1 he wouldn't have had a get out.

Now he might well say that you removed the switch, b******d it all up and are trying to blame the previous tenant.

But might be worth a try.

Anyway - that switch isn't an intermediate, it's a 2-gang 2-way. Do either of the gangs work? Are there 2 lights in the room which it could have worked?

As for the wiring it is perfectly bog-standard 2-way where one switch (or in this case one of the two gangs) has a switch drop and is connected to the other 2 way switch with 3C+E, and if you look in the For Reference topic, or the Wiki, you'll find clear diagrams showing how it all works, and TBH if you can't grasp it, and work out what you've got and what you need to do you probably shouldn't fiddle with it - electrical installation work shouldn't be done by following "insert wire A into hole B" type instructions without a clue as to why.

Somewhere there is/are/was/were either another multi-gang 2-way switch on the other end of the 2 x 3C+E cables, or 2 separate 2-way switches. One of the separate switches or one of the gangs will have a the switch drop cable that matches the side of the switch you show that only has the 3C+E strapper.

How you fix it depends greatly on which side doesn't work - if it's the one with the drop cable you're laughing, if it isn't then you'll have to run a new cable from the light to the switch, or find the other end and sort out the connections.

Really you should do that anyway, because what you may have now are concealed cables that don't comply with the Wiring Regulations (as there's no accessory to flag their presence).

And if you install new cables the Wiring Regulations now require them to be RCD protected.

This could end up being a non-trivial job, and you may find that your tenancy agreement forbids you from doing it. But don't be surprised if your landlord refuses to pay for the electrician...

 

[txacoli]

txacoli wrote:

The previous tenant

I never thought about the wording of my message - I'm the owner of the house and meant the previous occupant. I used that bedroom as a storeroom when I moved in and, as the light didn't work, I put a floor lamp by the door and used that for light until I eventually got all the boxes emptied and got round to replacing the bulb. I thought - wrong as it happened - that was the only reason it wasn't working!!!

ban-all-sheds wrote:

Are there 2 lights in the room which it could have worked

No. There possibly was, but all I have is the central pendant light. Like I said in the earlier message, it looks as if there is a cemented in switch area on the opposite side of the room, but I don't see anywhere else where there is another light - yet there are two switches on the thing, so there must have been at sometime. I was talking to my neighbour earlier and he seems to think that the previous owners had bedside lights at one time. He was apparently a bit of a DIY bodger and I think I may have inheritted his legacy?!? I've heard some stories about him today

ban-all-sheds wrote:

Somewhere there is/are/was/were either another multi-gang 2-way switch on the other end of the 2 x 3C+E cables, or 2 separate 2-way switches. One of the separate switches or one of the gangs will have a the switch drop cable that matches the side of the switch you show that only has the 3C+E strapper.

How you fix it depends greatly on which side doesn't work - if it's the one with the drop cable you're laughing, if it isn't then you'll have to run a new cable from the light to the switch, or find the other end and sort out the connections.

I'm a little worried about this. Am I likely to have problems with wiring that is blocked off and cemented in? And what about the wiring I don't know about - possibly to wall lights? If it's all blocked, is it okay?? And how the hell do I sort this mess out?? I've a two-way light switch that ostensibly operates two lights, yet all I have is one single pendant light on the ceiling that doesn't work and which I desperately want to replace for something more funky.

I think I'm going to have to get an electrician in unless someone has an easy option for me. Be honest guys and let me have it straight............And finally, if I do need an electrician, how do I know if I've got a good one and he's not ripping me off? I had a brilliant guy in my last house, but that was 230 miles away and I think he'd be unwilling to travel!!!

 

[ban-all-sheds]

I never thought about the wording of my message - I'm the owner of the house and meant the previous occupant.

Oh well forget the landlord getting it fixed for you then...

Like I said in the earlier message, it looks as if there is a cemented in switch area on the opposite side of the room,

You should probably turn off the power and have at that with a club hammer and cold chisel to see what you find..

I was talking to my neighbour earlier and he seems to think that the previous owners had bedside lights at one time.

Any traces of where they might have been?

He was apparently a bit of a DIY bodger and I think I may have inheritted his legacy?!? I've heard some stories about him today

I'm a little worried about this. Am I likely to have problems with wiring that is blocked off and cemented in? And what about the wiring I don't know about - possibly to wall lights? If it's all blocked, is it okay??

Not if it's still live. Basically cables buried in walls should be where you'd expect them, which means (according to the Wiring Regulations) close to the ceiling, close to corners of walls, or vertically or horizontally in line with switches, sockets etc.

These give you chapter & verse:

• http://www.voltimum.co.uk/files/gb/attachments/niu/l/attachments/c5-43.pdf
• http://web.archive.org/web/20061110111450/http://www.niceic.org.uk/downloads/concealedcables.pdf
• IEE article
• IEE Article on 17th Edition requirements for concealed cables.

If you've got cables where you wouldn't expect you could drill into them. If you're lucky there'll be a flash and a bang, a chunk will vanish from the end of your drill bit and the circuit breaker will trip. If you're unlucky your shelf bracket will become live...

And how the hell do I sort this mess out??

You could get a Periodic Inspection done, but that probably won't pick up things like this unless there are knock on effects. Do you have access to the loft, and to floor/ceiling voids? Can you trace the wires from the light and see where they go?

Do you have a multimeter? In the red/black cable is one of them live? Are any of the R/Y/B conductors live?

And finally, if I do need an electrician, how do I know if I've got a good one and he's not ripping me off? I had a brilliant guy in my last house, but that was 230 miles away and I think he'd be unwilling to travel!!!

Usual story - personal recommendations.

Failing that, pick one who is registered with one of the trade bodies.

 

[txacoli]

Like I said in the earlier message, it looks as if there is a cemented in switch area on the opposite side of the room,

You should probably turn off the power and have at that with a club hammer and cold chisel to see what you find..

I'm a little worried about this. Am I likely to have problems with wiring that is blocked off and cemented in? And what about the wiring I don't know about - possibly to wall lights? If it's all blocked, is it okay??

Not if it's still live. Basically cables buried in walls should be where you'd expect them, which means (according to the Wiring Regulations) close to the ceiling, close to corners of walls, or vertically or horizontally in line with switches, sockets etc.



This is all far more complicated than I would like it to be . I have one more question and then I'm going to call an electrician in............

Bearing in mind that I have just decorated and don't want to really hack into the wall with a club hammer and chisel, could the wires be cut and blocked in at the other end of the line (ie. at the light fitting and at the switch), making all wires benign apart from those leading to the central ceiling light and effectively turning it into a one-way single switch?? Then it wouldn't matter where the others were buried as they would just be wires and not connected to anything, making it safe if anyone drilled into them accidentally in the future??

 

[ban-all-sheds]

If you're sure you can find them all - you need to make a start on that anyway if you want to get your light working...

 

[txacoli]

Thanks for all your help with this. At least I now know that it's something I shouldn't be doing and will let an electrician at it. Anyway, your time and patience is greatly appreciated - and if you live near East Sussex, come and quote me for the job!!!!!