Wireless Switch for New Light in UK - Best Solution?


First time poster here - I’ve had my hub for a few months now and have been gradually switching things over to SmartThings in my home - lights (typically Tradfri, Lightify), TRVs (Danfoss), a few motion sensors (Samsung) to automatically turn lights on/off, a multi-sensor (Samsung) to tell me when mail has dropped into my outside postbox (still in progress). I’ve a development background so am also familiarising myself with handlers, smartapps, CoRE etc but haven’t yet started cutting any code.

I do have a very specific requirement that at first glance sounds like it has already been covered bythe many quality threads I’ve read here, but I’ve not managed to identify a solution that is right for me. So, I thought I’d ask. Here’s my requirements:

  • We are in the UK
  • We recently moved into a house that has a 4 meter high ceiling living area but that area has no ceiling lights - that part of the house has floor level 5A sockets with floor lamps
  • The boss want to add a couple of pendants to the ceiling and I want to be able to control those from SmartThings
  • However, we also need to be able to control the lights from a wall mounted switch
  • I have an existing powered wall switch i could expand/re-purpose if required (2 wire system)
  • We have access to the loft space above the living area and can get wired power to the pendants
  • However, there’s no non-destructive way of getting wires from the switch to the pendants
  • The solution can’t be internet reliant - I i don’t want to be in the situation where I’m away for work and my wife can’t turn lights on and off (ie. has to be local processing)
  • The solution could be internet reliant if the manual switch still worked during any outages
  • The pendant doesn’t have bulb fitments for bulbs can be ST controlled (ie, not E14, E27 etc)

Can what I’ve after be done with ST and the Fibaro modules or with another ST compatible module? eg, a Z-Wave notification switch (or behind the switch) and a Z-Wave relay above the lights with a smartapp controlling it? Or would that automatically make it cloud based?

I’ve read many posts here and articles on other sites (eg, vesternet.com) but haven’t yet found the right solution for me.

I’d rather not have to go down the Lightwave RF route or another non-open solution.

Or do I just need to accept that my plasterboard is going to get some collateral damage, run wires from an existing wall switch, and install a Fibaro module either behind the socket or above the light?

Any thoughts appreciated.

You could use the Fibaro dimmer module which I don’t believe requires a neutral at the switch (dependent upon wattage levels etc)
Then you could use whatever pendant light fitting you want
the great thing about the fibaro modules it that they can be manually controlled with a normal light switch even when there is no internet.

One of the guys here is in the UK and have done his whole house with fibaro units @anon36505037
Now that I’ve tagged him he will probably be along soon to advise.

HI @Cobra, how would the dimmer module control the pendant without the line between the switch and the pendant? Won’t i need both a controller at the switch and a relay at the pendant?

Basically, you would wire the pendants in the conventional way then place the fibaro unit behind the switch (or at the pendant if nor room behind the switch.
The switch is then wired to control the fibaro… then the fibaro controls the light

The Fibaro is both controller and relay (sort of)

Does local electrical code allow for a light and the controlling switch to not be on the same circuit? I think the concern would be that someone wanting to do work in the switch box could cut power to the light via the breaker, assume there was no power at the switch, and then get zapped. Of course, people do things that aren’t to code all the time, but it’s something to consider.

Edited to add: code probably doesn’t consider a situation where the switch can control a light that isn’t on its circuit, I don’t know if many locales or the big councils like NEC/IEC have updated them to consider smart devices.

The Fibaro replaces the switch in the circuit… so cutting power to the circuit will also cut power to the fibaro… leaving unpowered lights no matter what you do with the switch

As I read it, OP’s proposal was powering the switch from one existing circuit and supplying the lights from elsewhere.

in the UK the lightswitch in effect just cuts the live wire from fusebox to pendant light.
I would expect this to be the same

HI @Cobra - I’m still missing something here. If the pendant is wired to the mains only, with no wire to the switch, and no fibaro relay, how can a fibaro behind the switch control it?

I can see the scenario with the relay at the light, and another controller at the switch controlling that relay (via ST) but I’ve not seen that setup proven anywhere yet.

Perhaps I’m missing something major here on how the fibaro modules work - electrical engineering is not my thing.

Maybe it’s me assuming too much about your current wiring…
What does your existing lightswitch control?

Yes, that’s correct. There is no wire from the switch to where the pendant will be and it will be plasterboard-destructive to introduce one. I’d also be ok going for a battery operated wall switch communicating with a relay at the light. But my ideal would be

  • The hardware switch must work during internet outages. It would be acceptable to have to flip the switch a couple of times to get the power back on during an outage
  • Powered switch so no need to replace batteries
  • Ideally not cloud based to reduce latency and minimise the chance of “lost” messages from the switch to the relay above the light

Thanks for all the feedback.

It controls the existing 5A floor lights. I mentioned that as a powered wall switch would be ideal, but a battery operated one would be acceptable.

this is where I was getting confused.
I had assumed that the wires from the lightswitch went to the area of the pendants.

Thanks @anon36505037, that helps. Does ST support direct associations? I’ve not done much reading in this area yet, but I have read that ST doesn’t support some of the more complicated aspects of the protocols.

Yup, thought that might be the case :slight_smile:

I hoping to not have to pay an electrician and a plasterer! The former is a friend and will do things at mates-rates and i’m hoping to avoid the latter.

Perfect, thanks @anon36505037 - some reading for me.

So it sounds like a dimmer behind the switch and the relay at the pendant is the solution?

Once i read through that, i’ll come back and ask about the actual physical switch. eg. What happens with the existing toggle switch in the case where the light is switched via ST rather than that switch. Can it then work as a true toggle (ie. up or down can mean on or off) or would it be best to replace it with a momentary switch.


I’ve now purchased 2 Fibaro Dimmer 2 and am testing things in another part of my house before putting the solution in place in its final resting place.

I’ve got the first Dimmer 2 working with the wall switch, powering a light using the DTH recommended above.

I now want to install the second Fibaro above a ceiling light, and have an always-on load to that light and then use the first switch/Dimmer 2 (disconnected from the light) to control that with direct association,

However, I’m not 100% sure which wiring diagram to use - the wiring in my ceiling light is very simple - just the single blue and brown wire (neutral and live?)

Can anyone share how would I wire that so I can then set up direct association via the DTH? The diagrams I’ve seen all seem to have wiring from fuse board/previous light and the switch.



https://www.vesternet.com/resources/application-notes/apnt-138 (Installing in Ceiling Rose)

Is this what I should be following?

Any thoughts appreciated. I’d typically ask my electrician friend but its his birthday today so didn’t want to interrupt him :slight_smile:

Actually from the looks of that… That wiring contains the switched live and neutral, no live, hence you will need to install the Fibaro behind the switch otherwise your existing wall switch will just disable/turn off everything.

The reason I say that is that there is only a single wire coming into the fixture, it is a ceiling fixture, and the wires are literally patched from ceiling wire (grey wire) straight into the wire which goes to the light.

Sorry! :zipper_mouth_face:

1 Like

No problem @cjcharles, you were right from that picture, but that was just a test in one part of the house. I’m going to be installing this in a less accessible part of the house so wanted to test in first. In that new part of the house, the light will be hardwired from another circuit with a master on/off in a cupboard near the new location - it could end up fitting the fibaro behind that switch rather than above the light.

I managed to get the direct associate working yesterday via @zcapr17 excellent DTH.

The first Dimmer 2 is on one switch circuit (I left it still controlling its own light so as to take some load) and flicking that switch also controlled the the light on the second circuit (with the fibaro above the light and with power on at its own switch to simulate my final solution).

The first switch is not a dimmer so could not test that association but see no reason why that would also not work.

My biggest challenge was trying to get the fibaros to sync as I didn’t purchase the Bypass 2 module and was struggling to get enough loads onto the circuit. I’ve ordered that today.

Once I get it all working in my final solution, I’d like to document this since all the information is out there but a single page for this solution, with wiring diagrams, would have helped me.

Thanks everyone for the help/input.

1 Like