Landing and bathroom light switch- Help!

Hello- I really need some advice.

I have a double switch downstairs that works the hall and landing and one upstairs for the landing and bathroom.

I changed the switches for new ones yesterday, took pictures of where the wires went and thought everything was fine (i tried all four switches on and off) until on going to bed, i discovered that I couldn't switch the landing light off from upstairs if it had been turned on downstairs and vice versa.

I'm hoping someone can help- I've included a picture of the upstairs lightswitch. View media item 7100 [

(also for additional info, prior to my changing switches yesterday, the downstairs switch toggle 'buttons' worked the other way round- up for off and down for on and I did want to see if I could change that by turning the switchplate around but some of wires were too short to reach so I returned the switch to how it was and then found that it was 'fixed' anyway. I appreciate this probably has some bearing on the current problem but I honestly believe I returned the wires to where they were before and since this is how I wanted the downstairs switch to work, I would really appreciate a solution that doesn't require me to change that switch again. Though any help would be much appreciated)

Thanks so much for looking!

The black wire hanging out might have something to do with it
Also as a metal switch you need to ensure there is an earth wire to the earth terminal, hopefully you will have a number of earths to the back box? You need to run a short piece of earth wire from there to the switch earth terminal.
How were they wired before? Can you upload the photos?
How is the downstairs one wired now? Which switch is which?

Thanks for looking- I was aware of the black wire in the pic- not the problem!
There are two green-sleeved earth cable that are coonected to the back of the box, yes.
This undoubtedly will sound stupid but how do I 'run a short piece of earth wire from there to the switch earth terminal'? I presume you mean the earth terminal on the back of the switch plate? Where do I get a short piece of earth wire from?

I have just unscrewed the downstairs one to check and it is definitely wired up as before and the upstairs switch is wired up as before just in a different switch- I more or less took the wires out from one switch and into the other one by one to make sure. Downstairs switch has two cable- two each with one black and one red wires. Both black and one of the red wires go into the L1/L2 slots and one of the red wires goes into one of the COM slots where a shorter red wire connects to the second COM slot. (Sorry- I don't know correct terms!) but thes same wires are going into the same place as before.

Upstairs switch has 3 cables- two with red and black wires and one woth just a red wire. The single red wire goes into a slot which in this case is labelled 'L' instead of COM, and one of the black wires (belonging to the bathroom light) goes into the other L slot. The rest of the wires go into the L1/L2 slots (except the earth wires).

the red and black cables in the upstairs switch are from the downstairs switch they are called strappers and connect to L1 and L2.
The single red up goes to the light and there will be a single red downstairs in the com terminal thats permanent live.
You need to find out which wire goes where id suguest isolate the supply and short out the red and black wires from L1,L2 upstairs and bell them out with a continuity tester downstairs as they may be mixed up.

Thanks for the reply streetlighter but I'm afraid you will need to use layman's terms with me- i'm not to good on the tecchie language, armed though I am with a collins electrical wiring and lighting book!

I know which cable in the upstairs switch relates to the bathroom and so the other red and black wires must be linked to the downstairs switch- these are already connected to L1/L2.
The black cable for the bathroom is in one of the L terminus (which I presume is the same as COM?), the red bathroom wire in the other L1/L2 terminus- it has been tried in both- and the live cable (the single red) is in the other 'L' terminus- which I presume is where it should be?

I did wire it up as it was and need any other suggestions to why i can't switch off the light upstairs if it's on downstairs.

Can you post a pic of the other switch? The one you have posted is the upstairs one?

Thanks to anyone who looked at my problem but I managed to sort it out yesterday- I had made a minor error with the terminus I put one wire in (in the downstairs switch) so the light works from both switches now just fine.

Also, I didn't realise it made a difference which way round the red and black wires went into the R1 and R2 termini but it does! I've worked out that it affects the way the switch works so all the toggles are now turning the lights on (or off) the way I wanted them to. I'd be quite chuffed with myself if it hadn't taken me all day to work it out.

Thanks again to all those who posted a reply!

norahclare said:

There are two green-sleeved earth cable that are coonected to the back of the box, yes.

Click to expand...

That's good

This undoubtedly will sound stupid but how do I 'run a short piece of earth wire from there to the switch earth terminal'? I presume you mean the earth terminal on the back of the switch plate? Where do I get a short piece of earth wire from?

Click to expand...

You can get a new piece of wire from any electrical shop, usually sold in metre lenghts for 1mm twin and earth or 1.5mm twin and earth for lighting. You'll also need some green/yellow earth sleeving. Strip a short piece of the middle wire out of the cable and cut it off, use this to connect from the screw in the back box with two green/yellow earth wires in to the earth terminal on the switch, sleeving it as you go.
Alternatively ask any spark and they should be able to set you up with the items needed.

Or you could use a small lenght of 1.5mm2 green and yellow singles insulated. You can buy a small coil of this from most B&Q stores.

For some reason, toggle switches are wired upside down - meaning that you have to wire COM - L2 for a one way, etc. Does anyone know why?