Landing light swiches off all downstairs lights

[VeryBaffled]

We've just decorated and changed our light switches. Done this before with no problems but this time something strange has happened. If we switch the landing light on from either upstairs or downstairs all the downstairs lights go off. If we switch it off they are all fine again. Checked all the switches and wires and can't see an obvious error. Any ideas?? Thanks in anticipation of your help as it's driving us mad!

 

[leeco]

The strange thing that happened is that you don't understand 2 way switching.

Look it up on here it might help you but you are messing with lots of live switch wires and loop wires so you may need a tester yo help you out.

You need to find the loop wire and the other loop wire that feeds the next light and put it in com on the switch.

 

[sparkwright]

We need details of exactly how each hall and landing switch are wired.

Pictures would be even better if possible.

 

[VeryBaffled]

Thanks, we have a tester but are not sure what to test....
Cant attach a picture at the moment but will try later. Downstairs switch controls outside light, hallway and landing. Upstairs switch just does landing. If we switch hallway and outside light there is no problem but if we use either landing switch it turns off lounge, kitchen etc. Does this provide any clues in the meantime?

 

[ban-all-sheds]

Thanks, we have a tester but are not sure what to test....

What sort of "tester"? It needs to be a proper 2-pole one, not a neon screwdriver or magic glowing wand. And you do need to know how to use it, which means you do need to know how lighting circuits work so that you know what you are testing for where.

There really is only Plan A or Plan B:

PLAN A:

• Learn how lighting circuits are wired.
• Get a multimeter and learn how to use it.
• Identify which conductors are which at the switches and the light positions.
• Check for voltage present, circuit continuity, switches working etc.
• Connect everything up properly.

PLAN B:

• Get an electrician.

PLAN C:

• Start trying different things without really knowing what's going on, hoping to get it working by luck, or by blindly following instructions to put-this-wire-in-that-hole without any idea as to why.

There is no Plan C.

 

[sparkwright]

Thanks, we have a tester but are not sure what to test....
Cant attach a picture at the moment but will try later. Downstairs switch controls outside light, hallway and landing. Upstairs switch just does landing. If we switch hallway and outside light there is no problem but if we use either landing switch it turns off lounge, kitchen etc. Does this provide any clues in the meantime?

Hard really to give a sensible answer at the moment, but with pictures I think we should be able to give you lots of help.

 

[VeryBaffled]

View media item 88499 View media item 88500 View media item 88501
Hopefully the three pictures are attached.
Picture 1 shows the 3 gang switch in the hallway downstairs. Left switch is a two way for the landing light. Centre switch is for the ground floor hallway, front switch is ground floor outside light.
This is wired as top (left to right) red, blue, red, gap, red. Bottom, yellow, gap, black, black.
This switch was changed from a white one four years ago and has operated with no problems in the meantime. We didn't change it although we have now taken it off to review etc as this seems to be the only link to the problem as the left switch is two way with the upstairs circuit. Everything else is simply on the downstairs circuit.
The other two pictures show the downstairs switches in the lounge. These were changed just prior to the problem.
Just to remind you the problem is that when we switch either the upstairs or downstairs landing light switch on it switches off the entire ground floor.
One of the lounge switches is a dimmer but we have simply moved this from the other switch. The other is a new screwless switch but we have put back in the original basic white switches and still get the same problems which would seem to eliminate a faulty switch.
Hope you can help - really appreciate your time.

 

[Taylortwocities]

An additional query and an observation:

Query: Was it just the switches that were removed/replaced, or did you also change/move/rewire any of the light fittings themselves.??

Observation: Those light switches need earthing! That is what the EARTH terminal is for.

 

[VeryBaffled]

Thanks for such a prompt reply.
We changed the lights in the lounge about 3 months ago but all seemed ok and the present problem wasn't there. The only thing that we did find was that we have blown a few bulbs which blows the fuse for the downstairs light circuit but I put that down to cheap bulbs.
I'm confident the earth is connected on each switch - perhaps the pictures don't show this very well.
Thanks for your help

 

[bernardgreen]

I'm confident the earth is connected on each switch - perhaps the pictures don't show this very well.

Untitled

• bernardgreen
• 19 Jan 2015
• 1

Do we have invisible earth wires ?

 

[VeryBaffled]

Thanks again, I can see what you mean, really helpful diagram.

I've checked again. The answer is that the earth is connected to the metal box and the switch plate is metal and so when the switch cover is back on the wall it should all be earthed.

Hope you agree?

 

[ericmark]

I am trying to work out what you mean by switches off all down stairs lights sorry if I have missed something.

1) When you move landing light switch back all lights come back on.
2) When you move landing light switch back and do something else as well like re-set RCD all the lights start to work again.

If you are re-setting a MCB or RCD then we are looking at something completely different to simply switching the switch back.

If it is simply the switch then I would assume there is a link wire somewhere.

if you look as switch J4 it will make no difference swapping brown and blue wire. (In yours red, yellow blue rather than brown blue and grey) but if there was a link from brown to other switch then it would affect other lights.

The left picture shows a switch with red, blue and yellow some where there should be a matching switch with same three colours.

If however it's a RCD tripping then I would guess you have a red wire in the wrong hole.

On the switch you show it has L, L1 and L2 for each switch. Often switches are marked Com, L1 and L2 or even L1, L2, L3. The L and Com must be in correct hole. If L1 and L2 are swapped all it means is switch works other way up but still works.

 

[ban-all-sheds]

The answer is that the earth is connected to the metal box and the switch plate is metal and so when the switch cover is back on the wall it should all be earthed.

No - you should connect the earth wire directly to the earth terminal on the switch.

 

[VeryBaffled]

Good point. I think I will earth the switch as you say as in all the confusion over the rest of the problems I had overlooked the fact that I now have a metal plate rather than a plastic one so better to be safe than sorry!

As for when I switch the landing light off, that solves everything without me having to do anything else. Temporarily I'm not using the landing light and all is fine except for the fact I can't see to get up the stairs!

Not sure I totally understand the other diagram but I'll have a ponder on your thoughts - if you can think of an easier way to explain it to me even better.

Thanks both, I'm really grateful for your help as I can't help but feel there is a simple answer to this one that I'm missing.

 

[sparkwright]

Are there two lighting circuits - eg upstairs and downstairs? Have a look at the consumer unit, they may be labelled.

Were there any link wires at the 3 gang switch?

Just wondering if a pic of the upstairs landing switch may help.