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Hi all, I am looking for a little bit of advice if you don't mind...

I have recently purchased a new build home and we have installed some new lighting in the kitchen/dinner and I want to change the normal switch for a dimmer switch...

Currently the normal switch has 2 switches on and I have bought a 2 switch dimmer to replace with.

When I took the switch off the wall I am a little confused as to the wiring, I tried wiring it up exactly the same from the switch to the dimmer but it the lights wouldn't work when I put the power back on.... I don't want to start swapping wires around without a little advice.

photo 1.JPGphoto 2.JPG

If you look at the images I have taken a pic of the existing light switch which works, I am not sure how clear it is but the neutral blue wires are all joined in a connector and not in the switch at all, the brown live wires are connected to the L1 and L2 terminals and a separate wire is going from L1 to L1

Here is a pic of my new dimmer switch

Please can someone advise to how I need to wire this up? Or should I just bite the bullet and get an electrician in?

many thanks in advance!

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  • Thread Starter Thread Starter
  • #2
It would take an electrician 2 Minutes mate. Pretty simple stuff. Bite the bullet, least you know its correct.


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  • #3
L1 on the old switch is just the common. So L1s in common and l2s in l1. If that doesn't make sense get a electrician in. Obviously you need the link between commons

Adam W

  • Thread Starter Thread Starter
  • #4
You should be able to wire the new switch the same as the old one - the link goes between the common conductors along with the feed (the wire with them) and the other 2 wires go into L1.

Remember to turn the power off at the fuseboard before you do that of course!

Deleted member 9648

  • Thread Starter Thread Starter
  • #6
You may find it tight getting a dimmer on that plaster depth box,take great care not to pinch any wires......One reason to always install 35mm deep boxes on switches,especially where feeds are taken to the switch.

Edit...clearly farmelectrics thinking along the same lines 1minute before me!

Richard Burns

On your old switch you have
L1 L2 L3 for each switch
on the new switch the terminals
C L1 L2
are the equivalents on each switch.
If you wire the new switch using this conversion it should be OK.


  • Thread Starter Thread Starter
  • #8
If this is a new build then chances are its a fluorescent light, so when the dimmer switch is connected correctly I will wait for the "since fitting a dimmer switch the RCD trips when I switch the light on", post!!!!


OP says he's installed some new lighting. hopefully he has binned the useless CFL rubbish
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