UK 2 way light switch not working correctly

rlink0216 · Sep 16, 2024

Hi,
I replaced a 2 way light switch and seem to have issues.

For context, I have a hallway switch which is a 2 way and kitchen switch which is 2 way. I replaced the kitchen 2 way that operates both the kitchen and hallway lights. The kitchen lights work fine however there is an issue with the hall lights.

Please see two situations below.

Hallway switch On (Hall)
Cannot switch hallway light off from kitchen
Can only switch off from hall

Hallway switch On (kitchen)
Cannot switch hallway light off from hall
Can only switch off from kitchen

Seems the switches are working independently but not together

Attached is the original hallway/kitchen switch cables.

Would anyone be able to advise what the issue is ?

The terminals on existing are A com, A1 and A2 and B com, B1 and B2

The new switch has two lots of com, L1 and L2.

[ElectriciansForums.net] 2 way light switch not working correctly

Original Wires

Thanks
Russell

brianmoooore · Sep 16, 2024

What is the pic of? That switch doesn't look new.

rlink0216 · Sep 16, 2024

brianmoooore said:
What is the pic of? That switch doesn't look new.

Sorry that's the original wiring before I connected the new switch.

brianmoooore · Sep 16, 2024

rlink0216 said:
Sorry that's the original wiring before I connected the new switch.

That's why I can't see anything wrong with it , then (apart from a little to much exposed copper where the red and yellow share a terminal).
A pic of the new switch and wiring might help.

rlink0216 · Sep 16, 2024

brianmoooore said:
That's why I can't see anything wrong with it , then (apart from a little to much exposed copper where the red and yellow share a terminal).
A pic of the new switch and wiring might help.

Ok will take one tomorrow in daylight. Thanks

rlink0216 · Sep 17, 2024

rlink0216 said:
Ok will take one tomorrow in daylight. Thanks

rlink0216 · Sep 17, 2024

New switch

littlespark · Sep 17, 2024

On that last photo, the 2 reds are mixed up.

The red and black of the same twin cable needs to be with yellow and blue of the 3 core, in L1 and L2. The red of the 3 core on its own in C

The switch side with only single red, yellow and blue do not need to be touched.

rlink0216 · Sep 17, 2024

littlespark said:
On that last photo, the 2 reds are mixed up.

The red and black of the same twin cable needs to be with yellow and blue of the 3 core, in L1 and L2. The red of the 3 core on its own in C

The switch side with only single red, yellow and blue do not need to be touched.

Thanks for your help. Before I test and turn on the the electricity,
Do you mean as in the below

rlink0216 · Sep 17, 2024

rlink0216 said:
Thanks for your help. Before I test and turn on the the electricity,
Do you mean as in the below

Obviously making connections tight beforehand.

littlespark · Sep 17, 2024

Last photo looks correct, but difficult to see which wires come from which cable.

Try to have less bare copper showing as the wire enters the terminal. You might need to trim it a little shorter… but obviously not too short that the terminal screw doesn’t hold it.

rlink0216 · Sep 17, 2024

littlespark said:
Last photo looks correct, but difficult to see which wires come from which cable.

Try to have less bare copper showing as the wire enters the terminal. You might need to trim it a little shorter… but obviously not too short that the terminal screw doesn’t hold it.

Thanks again for your help, now solved