Physical switch not working with Fibaro Dimmer 2

Hi all,

I’m having some work done and decided to change all my light switches to BG Nexus switches like this:

The problem I have is the new switches don’t seem to work with the Fibaro Dimmer 2. The smart functionality works fine, I can turn on/off and dim with SmartThings but the physical switch does nothing.

I’ve tested the switch on its own to confirm it actually works and it’s fine.

Is there anything I can do or will I need to change the switches?


I posted this a few days ago. See if it helps.

You can only dim fibaro dimmer 2 with a momentary switch, you can’t use your standard UK dimmer switches which have a resistor.

It’s coming back to me now, it’s that long since I originally installed my current ones.

I’m guessing these will work:

We’ve bought a few £100 worth of the same brand/line of sockets, CAT6 plates etc. so need to keep the other half happy!

I can’t tell for certain that that Nexus Grid module is what you need. I used a Scolmore mini grid module. With Scolmore you use a 2-way retractive (aka momentary) module.

I used the Scolmore Polar White face plates with the matching Scolmore minigrid modules also in white. This mix best resembles a standard UK white switch.

With 2-way up might be dim up, down might be dim down and centre is do nothing and is where the switch rests when no-one is pressing it. With the Fibaro module it also supports tapping up or down to turn on and off, it is holding it pressed that causes dimming up or down.

Scolmore also do brushed steel versions of both their faceplate and modules if your interested.

I am sure some of those Nexus modules will work with the FIbaro dimmer but whether it will work in exactly the same way as Scolmore I am not sure.

I had a look at the BG website and confusingly they do not seem to list a brushed steel 2-way retractive module. Based on other information on their website e.g. about the white modules it should be part number GBS14C and yes that is the part number listed via the link you provided. Except the BG brochure implies it does not exist as there is a blank box in the table for that item!

As per the Versternet article the Scolmore part number would be MD004BS with BS signifying brushed steel.


I have a 2 way retractive switch, exactly as you’ve decided. My setup used to work exactly as described.

I presumed that samsung, at some point, changed the something. Because it doesn’t work that way now.

Could you please verify whether your setup actually functions the way you describe, or are you quoting info you’ve found? Again, mine used to work that way. I set it up following the same documentation.

If you don’t mind I’d be interested to know how your settings for the DTH are set and also, how you’ve wired it.

Much appreciated!

I bought a Fibaro Dimmer 2 and the Scolmore switch to build a test setup. I intend to redo the entire house for smart lighting when I replace my roof and build a loft conversion. As such I am not using the Fibaro for real but my test setup did work with the switch and Smartthings when it was setup.

I used the DTH as from the following thread.

I also programmed the Fibaro module so it was setup for use with a momentary switch as per.

This requires programming for a 3-position momentary switch and also using a 3-core plus earth cable between the switch and the module. Older UK lighting circuits only have 2-core plus earth. My plan is to rewire during my renovation project.

I since setup an Insteon micro dimmer module with the same physical switch and it also worked both with the physical switch and Smartthings using a different DTH. My ultimate goal is to have wired switches and smart lighting control that work with both Smartthings, Alexa and Apple HomeKit. Fibaro is unlikely to meet that requirement in terms of HomeKit but Fibaro does offer the ability to do everything else I wanted such as mixing dimmers and switches, supporting pull-cord switches and so on. Insteon have indicated they plan to release a new hub which will add HomeKit support but it has been a year since and nothing yet has happened. I could in theory use HomeBridge to add HomeKit support but would prefer and official solution due to the danger that Apple will kill HomeBridge at some future date.

I have been looking for a smart lighting solution for a long time because I have my own tough criteria but I recently discovered a new not yet shipping product which sounds hopeful. It sounds like it would be a lot more expensive than either Fibaro or Insteon but will have official HomeKit support and supposedly will fit easier at the light switch end whereas Fibaro and Insteon realistically need to go above the ceiling rose.

As my home renovation project is still some time away from happening I have been able to research, experiment and wait.

Thanks. Do you recall how long ago your test setup worked with the fibaro? Again, mine worked fine (for about a year) and at some point fairly recently, just stopped. I’m not doubting your test setup worked, but I’m unsure if it still will. I’d hate anyone to waste their time. =)

If its worked in say, the last few days I’d be very interested in the DTH settings. Ta

It would have been at least a year ago. The DTH does not seem to have changed since 2017 so any change is more likely to be due to firmware updates.

Yeah, installed mine a year ago (ish) and stopped working as expected sometime over the past month or two. Difficult to say, as I usually only use the physical switch to turn off - very rarely on (“on” usually controlled by SW). So very difficult to pinpoint when it stopped working.