Fibaro dimmer 2, 3 wire question (UK)

Fibaro dimmer 2 (FGD212), 3 wire question (UK)

Morning all - I know there are a few threads on wiring in a 3-way switch.
I’ve read through loads, had a search on Google and some of the DIY forums and also looked at the wiring diagrams on vesternet, but I think I am more confused now than when I started (If that’s possible?!)

What I’m trying to do is install 3 dimmer modules into a hall/landing setup

This is what I have at the moment (all toggle switches):
3g 2-way switch by front door - (1x switch for outside light, 1x switch controls the hall light, 1x switch controls landing light)
1g 2-way switch in hallway - turns the hallway light on/off
1g 2-way switch on the landing - turns the landing light on/off
Neutral available in 3g and neutral available in 1g on the landing, but no neutral in the 1g hallway switch

Given I wont fit three dimmers into the 3g single box, I thought I would fit one dimmer into the landing back box and then I might be able to squeeze the other two into a 47mm deep back box on the 3g for the outside light and the hallway light – that way I am utilising the backbox’s that have neutrals available and will work for either led’s or straightforward on/off switching of CFL’s.

What I have in terms of wiring on the 3g;
First Switch - 1x brown wire on “L1” and 1x brown wire on COM (this is for the outside light)
Second Switch - 1x brown wire on “L1” and 1x Grey wire with Brown sleeve on COM, 1x brown wire on “L2” which is also sleeved in brown - there is also a link wire between COM on the first switch and “L1” on the second switch – This switch is connected to the hallway switch
Third Switch - 1x brown wire on “L1” and 1x grey wire with brown sleeve on COM, 1x black wire sleeved with brown on “L2” – This switch is connected to the landing switch

What I have in terms of wiring on the 1g 2-way switch in hallway;
1x Brown wire on L1
1x Grey wire with brown sleeve on COM
1x black wire with brown sleeve on "L2

What I have in terms of wiring on the 1g 2-way switch on the landing;
3x Brown wires on L1
1x Grey wire with brown sleeve on COM
1x black wire with brown sleeve & 1x brown wire on "L2”

I am just completely baffled

Not sure how I am supposed to replicate the Installation at Switch A position and assume i can replicate switch A at switch B (for the landing) given I already have the neutral there and what I assume is Live on L1 given the link wire to bridge the com and L1

I would appreciate if anyone could offer any guidance please.


Thanks Robin,

The only thing is my ceiling roses are not like that. I believe they are what they call single core & earth so they only have live and switched live in them (i.e. there is no loop in/out either)

Does that make a difference?

yes only one rose per circuit i will double check but thought all three fittings were the same

Sorry I meant switched live and neutral so assume the rose was feed from the light switch only (with the exception of the hallway 1G as there is no neutral wire in here so they must just be strappers? which are taken back to the 3g switch)

I will try and draw up a schematic although don’t have a continuity tester so will try my best.

Unlikely. If your house is wired per standard you will have a lighting circuit (L, N and E) that starts at the fuse box and winds its way around all your light fittings. The switch circuits then drop down from the light fittings, with a 2-way or 2-way plus intermediate as extensions to the first switch. If you don’t have the wiring Robin shows in your ceiling rose then it could be hidden above in a junction box (or worse just a chock block). I have seen this typically when a standard pendant fitting was replaced with some decorative lighting and there was no room or facility for all the connections at the decorative light.

As Robin says, it will be there, you just have to trace it out.

1 Like

Thanks @anon36505037 & @siwilson - i ended up investing in a multi meter and think i have got to the bottom of some of it…well i have managed to install the dimmer 2 for the outside light at the moment anyway

1 Like