Replacing standard light switch with dimmer

Question

I have a standard light switch (on/off) controlling my living room lights, that I would like to replace with a dimmer switch.

Pulling the old light switch off, I can see that it's connected like so.

Two live wires going into L1, and one live wire going into L2.

I took note of this and wired the dimmer switch in the same way.

However, when restoring power and trying the switch, it doesn't work at all, as if no power at all is making it to the light.

I've ensured that the connections are in properly and secure. I've since fitted the old light switch again and it's working, so I know I've not damaged anything while replacing it.

Any suggestions, or does this look like a duff switch that I'll need to return?

I'm in the UK, if that helps explain the wiring.

Answer 1

L2 isn't L2 any longer

L2 was clearly one of the outputs on your old dimmer -- it isn't on your new dimmer. The output on your new dimmer is marked by the sine-wave-with-an-arrow-through-it (aka variable sine wave) symbol -- so put the wire from L2 into that port, and things should work.