Light Switch Ideas (UK)



Hi, I was wondering if anyone knew of any ‘works with SmartThings’ relays/switches that can be mounted behind a standard UK wall switch to control lighting. Crucially, without a Neutral.


Have you had a chance to look at the UK lighting FAQ yet? I think it will answer most of your questions. :sunglasses:

Although there aren’t any listed on the official “works with SmartThings” page for the UK, both the Aeotec and Fibaro brands are popular with UK users, and the Fibaro can be used without a neutral in many cases.

@RobinWinbourne is in the UK and has done his whole house with Fibaro kit, so he may be able to say more.


Awesome thank you!

I used to have Fibaro kit long before SmartThings but the house had neutral, didn’t think to look to see if they had 2-wire ones now.
New house (actually really old!) doesn’t have neutral in the wall and the cavity above the light fitting is really tight and quite unnerving to put a small electrical device in… fire risk etc.

Unless someone can confirm that the simple push/screw fitting of wire to Fibaro or other is ok and sufficient to then stuff in to the cavity without the need for a junction box or protective box at all?

(Robin) #4

Fibaro Dimmer 2 modules do not need a neutral, the relay switches do.

I wouldn’t recommend shoving any module into any cavity (except a sealed switch back box) without some form of junction box / insulation.

Depending on how deep your back boxes are and how many gangs per box, your best option will probably be the dimmer 2 modules mounted behind the switches within the back boxes.

16mm box - won’t fit
32mm box - one module only
47mm box - two modules (for two gangs) but it’s a squeeze

If you’re going into the ceiling with a module or mounting inside a stud wall behind a back box, I’d suggest using one of these tiny junction boxes for each module:

As you can see the Fibaros fit nicely inside but you do need to shave off a bit of the plastic moulding. It’s a snug fit that holds the module tight without putting excess pressure on it. Without a mounting box you will have live terminals exposed which is a definite fire risk :fire: and a big no no!

If you’re going into the ceiling you’ll find any hole needed to fit the box will be easily covered by even the regular pendant fittings so won’t show.

Last resort, if you’re really stuck for space, is to wrap the junctions of the module with insulation tape, but take care not to cover the vents in the side of the module as those are needed to dissipate heat.


@RobinWinbourne Thank you! Good to know about the Chocbox, that’s definetely a way forwards! Might just get away with ‘upgrading’ to a 32mm box. As they’re wall mounted and not recessed it will have to pass ‘Aesthetics Acceptance Testing’ by the other half! Wouldn’t want a deep box sticking out from the wall.

Cheers again guys. I’ll let you know how I get one.

(Robin) #6

You could always make your half proud by recessing them :wink:


Oh if only. We have a fairly fluid landlord who’ll let us do most things. But chasing walls and recessing sockets is not one of them :frowning:

(Robin) #8

Ahhh… the joys of rentals… I feel your pain!!