Advice on installing a dimmer switch?

27 Feb 2011
Reaction score
United Kingdom
Hi there,

I am a complete novice at electrics yet I decided it would be a good idea for me to install a dimmer switch..

This is for a simple 1 gang 1 way dimmer switch. I have turned the electricity off at the circuit breaker and unscrewed the existing light switch off the wall. What I have is two brown wires going in to L1 and L2 on the existing light switch. I am assuming that i take these wires out and connect them to the same L1 and L2 on the dimmer switch.

As the new dimmer switch is metal I am aware that some kind of earthing will be required and this is where I am stuck. Currently there are two blue cables and two yellow/green cables going in to a terminal block. Do I need earthing and if so what do i need to do? Do i need an extra earth cable to connect from the dimmer switch to another terminal in the block or is there something that needs to be done with the existing earths going into the block?

As i am a complete novice I would appreciate a response in layman's terms!

Thanks guys,

Sponsored Links
The 2 browns are your switched line so just connect them up as the switch you've removed, if your new switch has com/L1/L2 then connect 1 to com and 1 to L1.
The green/yellow will be the earths so add another bit of g/y in that terminal block and connect it to the earth terminal on the back of the switch plate, there should be one.
The blues will be neutrals so don't bother touching those.

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.

Are you a trade or supplier? You can create your listing free at DIYnot Local

Sponsored Links