2wire system, smart light switch and dimmer (UK)?

Hi everyone, just wanted to clarify if what Im planning to do will work out…as if not, I will need to think of a different strategy and do my shopping accordingly…

I would like to change my light switches to smart ones, I am in UK and with an old house which has a 2 wire system. Will it work if i connect my 2wires to fibaro dimmer, and than 3 wires (including neutral) from dimmer to the smart switch?

Thanks Robin for reply.

The thing is i still want to have a switch (which most likely will be used by my partner), which will have some functions i.e. dimming, scenes etc… i dont want to have a seperate battery controlled switch or remote next to the dumb switch as it would look awkward…plus some of the smart switches look really good…

Would I be able to imitate 3wire system by using fibaro dimmer?

I went down a different route than Robin.
I have used LightwaveRF dimmers and outlets.
You DO need to have their hub as they cannot connect directly with ST. You can then control them through ST on a cloud to cloud or via a Pi.
Not as straightforward to initially set up, but once you have you leave them alone.
The switches work manually or via ST.
The dimmers and outlets are a direct replacement for you existing ones.
Just another option that you might like to consider.
There isn’t too much in the UK I’m afraid.


Thanks Robin ‘I GET IT’, but some smart switches look really good, and I havent seen many decent looking retractive switches (or maybe i dont know where to look). But thanks anyway.

Hi bobbles, thanks for the reply… it seems like a good option which I need to look in to, the only thing that worries me at the moment is cloudTOcloud, the internet is still unreliable and my mrss would kill me if we would be left in the dark because of my gadgets :smiley:

It does look like I will have to use fibaro dimmers, and maybe set up a touchscreen for if Ill want any effects, or some other cool stuff…

If the internet is down I use my mechanical device. My finger…But that is the case for most home automation stuff.
With Robins’ option you can pick whatever standard switch you wish. The switch still works but you can also use ST to use automations.
It is a good option. Just a matter of which road you go down.

The one thing you need to be aware of with the Fibaro is if you fit them in the existing switch back box, you will need to make sure there is enough clearance. Some people fit them in the ceiling rose as per one of Robins screenshots.

WIth the LightwaveRF, do you have to fit like a dimmer behinde the switch? or does it support 2wire syst?

In case of no internet, when controlling mannualy, do you know how lightwave talks to its gadgets, is it wifi?

Im also trying to weigh the costs, with the fibaro dimmer if i want to change all the switches, that will be LOADS of ££ :slight_smile: … however still works out cheaper than rewiring the house

The dimmer is a direct replacement for your existing switch. Just turn off the power to the switch, remove existing switch, connect new switch. Simple as that.
It has its own built in dimmer as part of the switch.
No neutral required.

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Thanks Robin, these look really good!
I would prefer having most of my stuff on zwave, probably just need to open spreadsheet and work out the costs, to see if there would be a great saving by using lightwave for lighting…

Also some people mentioned delay when using smartthing and zwave sensors to turn on the lightwave controlled lights…

I don’t think LightwaveRF will work out as cheap as Fibaros and switches.
But when your starting point is a Lightwave RF hub and 4 switches and you then get into Smartthings I was already committed to the LightwaveRF product.

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I use a Raspberry Pi.
So the ST hub talks directly to the LightwaveRF hub. Not cloud to cloud.
Sensor > ST Hub > ST Cloud > ST Hub > Ras Pi > LW Hub (via Ethernet cable) > LW Dimmer.

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I might be wrong but i think RPi would eliminate Cloud… so than:
zwave sensor>ST Hub>RPi>RF bridge>RF Switch

I think Cloud would be causing the longest delay, but if that is eliminated i wonder if there is still a substantial delay i.e. 3s plus

Not really. Walk in room, light comes on within 0.5 secs. Not an issue for us.
Your right about the ability for local processing though. This will be never be available with this set up.

Sounds like we are getting into a “Who’s got the biggest dxxk” scenario. :wink: (I don’t mean duck BTW). :smile:

Did you fit fibaro dimmer behind every switch?

To cut the cost, in some places im thinking to add just a smart light bulb and leave standard switch always on… not sure if it would be a good option? also, i understand that these sort of lights would not be dimmable?

you say not dimmable through the switch, can it be dimmed via the app? if so, i could still set up something like after 9pm if motion sensor trigered to turn on light at 50%?

its just that fibaro and other modules are scaring me with its price…thats why im trying to figure out other ways, but as it seem there is no other real option than to use them.

Many thanks for your help today Robin, you cleared my mind a lot.

Even though cost does seem high with fibaro, but its still going to be cheaper than using lightwave and incorporating smartthings at a later time…

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It does work well.
As we are into mutual admiration, if I hadn’t already had the LW kit, I probably would have used Fibaro dimmers/switches.
I already use 2. These are for fans in the main bathroom and the EN Suite. Easy to set up and work well.
With the Fibs you also have a great range of switches you can use.

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Robin is my lighting idol! Follow what he says and you will be fine (although I have yet to sort out a double switch that need two separate dimmers and doesn’t have any space for the modules…there is a rose I can tackle but it’s a job for another day)

On a off topic question does the fibaro dimmers get firmware updates? As they work through ST cloud I can’t quite tell if there were ever updates in the past…if not wouldn’t it get tot the point you need to replace all the modules??? @smackbluefaceemoji@

@anon36505037, can I ask about these switches. I’m looking to use these too and ordered one - I went for a repackaged one from Amazon Warehouse so i could have a look before i ordered more. But, that one was just a toggle and not retractive. This is what I ordered:

I note the link you sent says “2 position”.

Are the ones you have true retractive with a spring load back to the default position?

It says 2 position under Specification,

eg https://www.ashdownhomestore.co.uk/retrotouch-2-gang-1-way-10a-pulseretractive-light-switch-white-glass-ct-00220-15759-p.asp

But I see now that they do both toggle and retractive versions of the same switch(es). Amazon warehouse only did the toggle version - it was the cheapest way to have a “look at it in the flesh and feel it working” test and, importantly, based on that, it has passed the wife approval factor so so I’ll be getting some of the retractive ones to fit where I have (and will be putting) the Dimmer 2s.


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Yup, and I was reading so many pages they all ended up looking the same. I worked it out in the end :slight_smile:

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