BATHROOM CEILING SWITCH

[Belboz]

Hope you can help!

Bathroom redecoration. Replacing light switch (ceiling pull switch)

Removed old one.

There are 3 red wires plus 2 earth wires (which seems strange) in the void.

Old pull switch had 2 of the red wires twisted together into COM and one red wire into L2 (there was no L1 on the old switch) The 2 earths terminate together inside the switch housing.

Replaced with new switch. Wires were placed in the same positions as the old housing. Doesn't work!!

Am I right in thinking that the old switch was being used as some form of celing rose?

I assume this because two other lights in 2 other rooms have also ceased working and I suspect the two reds which went into one connector are being used as part of a loop.

The switch only works the bathroom light and not any other lights.

Any ideas?

Sorry if not enough info on this.

 

[EFLImpudence]

If you have connected the same way as the old switch I can only assume you have screwed onto the insulation rather than the copper or the end of the copper has snapped.

It's unusual to have a 'COM' and 'L2' - Have you confused the terminals?

 

[AndyPRK]

Do the lights in the other rooms work when the bathroom light is on ?
YES - In which case you have the red wires mixed up.
NO - Probably a poor connection. Remove the 2 red wires from the COM terminal and make sure they are making contact with each other

 

[Belboz]

Thanks for the reply.

The old switch had 3 terminal 'slots' but only L2 and COM had brass connectors. The L1 slot was 'empty'.

The housing hasn't yet been screwed back into the ceiling (it is an older house with some sort of metal 'bell' housing into which the wires disappear into the loft) The switch unit screws into the base of it. However, as stated, I haven't screwed it back up yet so the wires haven't been screwed through.

I am wondering whether removing the switch has dislodged a connection further up in the loft??

That will be my next port of call (checking the wires in the loft) but posted here in case I had done something 'common' and was easily fixed.

If it's not easily identifiable, time to call an electrician. I am aware there is only very limited replacement type stuff I can do as an 'incompetent'.

 

[Belboz]

AndyPRK,

Thanks for your reply.

I tagged the wires with tape before working on them so I knew which was which. I also cut back some insulation on them to reveal fresh copper wires before wiring it up so they would get a good connection.

 

[sparkwright]

You haven't described the terminal markings on the new switch.

What are the terminals labelled as, and which ones have you used?

 

[Belboz]

The new switch is the same as the old one. It has 3 'terminals' but L1 does not physically contain a connector - only L2 and COM have connectors. L1 is 'empty'.

As a result, I have replaced the wires as they were in the old switch (see above) after having stripped them back a little to get a better connection.

 

[PrenticeBoyofDerry]

So you have but the two twisted reds to com and the single red to L2, now light in bathroom does not work and neither does two other rooms.
As EFLI has mentioned, check you have not trapped the insulation of the cables in com on the grub screw, but I expect these have remained twisted together therefore would expect other rooms to work.
Did you untwist them at all?
Other things is that again as EFMI has mentioned, the conductors have snapped/broken. or you have pulled out perm live from a terminal above.
Do you have a safe means of testing for voltage, such as a voltage indicator or multi meter?
If you untwisted them and made off the conductors again, it could be possible you have got the cables mixed up but would still expect some erratic switching and lighting, providing conductors are making good contact.

 

[securespark]

Using the procedures listed on this site, isolate safely.

Mark conductors so you know where they came from.

Remove all wires from switch.

Join them all together in a chock block and make safe.

Reconnect supply.

Does light illuminate?

 

[PrenticeBoyofDerry]

Using the procedures listed on this site, isolate safely.

Mark conductors so you know where they came from.

Remove all wires from switch.

Join them all together in a chock block and make safe.

Reconnect supply.

Does light illuminate?

joining all wires of switch together in a chock block. does not include the earths

 

[Belboz]

Thanks very much to all those who replied to this topic.

The mystery still waits to be resolved. I have called a mate of mine who is an electrician to take a look. He can test the wires (as I have no meter to test them) and confirm what I suspect to be the problem (break/loose wire further up)

I suspect this because;

(a) The single wire was tagged before removing the old switch (so no chance of getting the wires mixed up) straight replacement with wires placed in new switch as before. Nothing.

(b) Noticed wires were slightly oxidised at the ends so pared back some insulation to ensure good connection. Tried again - nothing.

(c) Tried placing all 3 red wires in connector block to see if things worked as they should (as I assumed connecting all 3 ought to complete the circuit/loop which the switch merely 'breaks') Nothing.

Given (c) above, that may indicate one or more of the wires may not be 'live'.

Sadly, all the wiring in the attic is housed in metal conduit and there is no inspection point for access between the metal switch housing and the metal ceiling rose housing. In fact, all the ceiling roses and the switch housings are cabled in metal conduit!

That means having to cut into the conduit to replace any cabling if that is necessary. I am assuming that such work needs to be done by a qualified person even though it will be 'replacement' of the cabling??

Anyhoo, thanks again to all for the kind replies. I will post an update on here once my mate has called round.

 

[sparkwright]

You shouldn't have to cut the metal conduit ever, you just draw new wires in if necessary.

Each switch point or ceiling rise point is an 'inspection box'.

Seems an odd problem, presumably the fault lies elsewhere.

Have you done any other recent electrical work that may have disturbed something?

Hopefully your mate can sort it. There's some jobs where you just need an experienced electrician actually on site for these sort of strange jobs.

 

[Belboz]

Thanks sparkwright.

Appreciate the info.

I don't envy my mate having to feed wires through without cutting into the conduit. The metal conduit looks like it's 15mm as opposed to the 'wider' plastic stuff. Looks like a difficult job to pull cabling through!!

At the ceiling rose end, there are 3 metal conduits going into the metal ceiling box (one from the ceiling switch point and the other two from each of the other lights in the 'loop') and so space is at an absolute premium.

Will see what my mate finds and wait for my wallet to empty............

 

[AndyPRK]

Maybe stripping the wires has pulled the wires out at the other end.

When all reds were joined did lights in the other two rooms work?

 

[Belboz]

Maybe stripping the wires has pulled the wires out at the other end.

When all reds were joined did lights in the other two rooms work?

Switch was tried before paring back. No joy. Ensured good connection (checked insulation not trapped) but nothing.

Was very careful not to pull on wiring when paring back. Tried again. Still nothing.

The other 2 lights didn't work when all 3 connected together (I would have expected them to)

Checked bulb - it works so it isn't that.

Still convinced there is an issue with the wiring further up especially given all that I've tried.

Will see what my mate thinks on Tuesday. He will check with his meter and that should narrow it down.