2 way switching help needed

[lennox]

hi got a 2 gang 2 way switch on the upstairs landing and it works landing and hall light. downstairs hall switch works the hall light.

upstairs switch has yellow in comm, blue in L2 and red in L1
downstairs has both reds in L1 with the red
black in L2 with the blue from the 3-core
3-core yellow in common

upstairs switch works perfectly but downstairs doesnt work at all, however if i take out the connecting 3 core it works.

help much appreciated

 

[EFLImpudence]

I think I've read it correctly but please just confirm this is how your switches are wired.

 

[lennox]

thats exactly how i did it

 

[EFLImpudence]

There's no way the downstairs switch would work if you remove the 3core wires.

You're not mixing up the 'commons' are you?
The L1 & L2 go with the common on the other end - not next to them.
As two triangles.

L1 L2.......C
...C.......L1 L2

 

[lennox]

ok just rechecked, both switches work but light is flickering

 

[EFLImpudence]

OR -

Is the downstairs switch marked L1,L2,L3?

In which case -

L1 = C
L2 = L1
L3 = L2

 

[EFLImpudence]

ok just rechecked, both switches work but light is flickering

Loose terminal somewhere or duff bulb or duff switch.

 

[lennox]

i have a curly line, l1 and l2

upstairs curly line - yellow
L1 - red
L2 - blue

downstairs curly line - yellow
L1 - 2 x red
L2 - blue and black

 

[ban-all-sheds]

Are they dimmer switches?

 

[fingers1]

hi got a 2 gang 2 way switch on the upstairs landing and it works landing and hall light. downstairs hall switch works the hall light.

This doesn't seem right because according to your description, you are unable to switch your landing light on until you are upstairs.
It is difficult to diagnose without checking the wiring.
By this I mean the RYB 3 core actually being continuous between switches and not broken or not connected in a joint box somewhere.
For the light not to work when all cables connected and both switches tried in all configurations has to have both L1 and L2 connections between switches severed.

 

[lennox]

yes they are 'ban all sheds' does that make a difference

 

[fingers1]

For the light not to work when all cables connected and both switches tried in all configurations has to have both L1 and L2 connections between switches severed.

Sorry, i meant to say it will not work if ANY ONE of the cables between switches is severed, I've just checked how it's wired.

 

[ban-all-sheds]

Yes - thats why they don't work, or why at best the light flickers - you can't have standard dimmers in a 2-way arrangement.

Did the instructions not tell you that?

 

[lennox]

ok thanks i'll go and get a switch without a dimmer