3 Gang light switch options (UK)

I’m currently decorating and fitting out my mums house, and on the lounge. Discussions so far seem to have deduced that smart bulbs will not be of use due to the choice of light, so her hue hub will not serve here. I need a smart option to replace the dimmer as seen here:

So far the only smart light switches I’ve come across this size are lightwave, which requires yet another smart hub for her. I’m looking for a ST compatible option to tie in with her current hubs without any additions. Is there such a thing?

Oh, and I am aware that Fibaro do a dimmer module, but don’t think it’s realistically an option to fit three behind this switch!

Tagging @RobinWinbourne

Robin will be able to best answer the questions about Fibaro as he has now done two complete houses all with Fibaro kit. I will say that one of the things to remember about any in wall micro is that it doesn’t have to be right behind the switch physically, it can be anywhere on the same circuit branch. Sometimes that means people put it in the ceiling rose, sometimes it can be put in a junction box elsewhere. So you are not restricted just to the size of the back box itself.

Also, in some cases you can use one “dual” micro which can handle two switches and then a single micro for the third switch. That way you only have to be able to fit two rather than three. But it does depend on the exact wiring and load specifications.

There are several good brands of micros, I believe the aeotec nano line is the smallest but there are new models coming out all the time, so do you check the dimensions.

One question we do need to get out of the way since this is an older switch: are there neutral lines coming into the switch box? If so, there is a much wider variety of smart switch options available. If not, you’re pretty much limited to either the lightwave RF, the aeotec nano dimmer, or the Fibaro dimmer in some models. But of course if you move a micro to elsewhere on the line there may be a neutral there. :sunglasses:

Also, I wouldn’t shy away from the lightwaveRF just because it has its own hub. That’s not really much different than using Phillips hue bulbs with the Phillips hue bridge, for example. Those are nice devices, they have an official integration with smartthings, they don’t require a neutral, and most people find the aesthetics good. Usually people look for an alternative because of the cost, not because they require an additional hub.

All in One Options

In addition to lightwave RF, there are some other all in one multigang options, where you just swap out the 3 gang smart switch for the dumb switch, and in theory, this should be easy as long as you have neutral lines at the switchbox. (I believe all the brands except lightwave RF require a neutral.) There are available three gang Z wave and zigbee switches.

Unfortunately, the smartthings platform has never implemented what are called “multi channel“ or “multi endpoint“ devices very well. That’s where there’s a single physical device but it has three or four or whatever individually controllable options. So the ones that you would expect to work, often don’t. And there isn’t really anything we can do about it. :scream:

There is supposed to be an upgrade coming on the platform side for Z wave multi channel devices, but it’s not here yet.

WiFi Switches

So… That leaves Wi-Fi devices. if you go to Amazon.co.uk you can find lots and lots of three gang Wi-Fi smart switches. They vary in quality and in safety certifications, but Sonoff and Meross are two good brands.

All Wi-Fi switches will have their own app, typically Chinese, and they work fine with that app. The question is how do you get them to work with smartthings? They don’t typically have an integration and there’s no industry standard for home automation devices for Wi-Fi the way there is for Z wave and Zigbee so many of these only work with their own app.

So now you have to start looking for a “man in the middle” to deliver integration. That could be IFTTT, it could be Amazon routines, there are a couple of ways of doing it.

SONOFF

People with strong technical skills used to be able to “flash” the firmware on sonoff devices To allow them to be used with smartthings without Requiring going through the Chinese servers, but I’ve heard that that no longer works with the newer models. If you’re interested in that, you can check the forums for the most up-to-date information

IFTTT

IFTTT can work well as long as The Internet is available, IFTTT is working, and the smartthings cloud is working. But that’s a lot of points of vulnerability for a light switch. You may be fine with that if it’s a situation where you’d be happy to go over and press the switch on the wall if the automations weren’t working. But it’s something to be aware of.

Also, some models offer two way communication and some don’t.

With one way communication, you could use smart pthings as the “IF” at IFTTT and the Wi-Fi switch as the “that“ and you would be able to turn the switch on and off from SmartThings. But if someone turned on the switch at the wall, smartthings would not know that the state had changed.

With two way communication, the Wi-Fi switch can be either the “if“ or that“ so you can create rules where if the Wi-Fi switch is turned on at the wall then smartthings gets notified of the change in state.

It’s up to each individual device manufacturer whether any given model has one way or two way communication, so you just have to check each one that you are looking at.

Amazon Routines

Amazon routines can give you some integration with devices that would otherwise be unavailable to smartthings, but it’s almost always one way. So it may be useful, it may not. And again, you’ve added a lot of points of vulnerability for a light switch.

Summary

As of this writing, LightwaveRF Remains the easiest way to do this. Their switches don’t require a neutral, they’re reliable, they’re safety certified, they have an official two way integration. It’s just that they are expensive compared to cheap Chinese devices.

There should be quite a few zwave or zigbee alternatives, such as the ones from MCO home or Schneider, but unfortunately, the smartthings platform just doesn’t handle this configuration very well at this time. They may do better in the future, or there may be some individual models which work OK. Hopefully if anyone has one that does work, they’ll add to this thread.

Aurora One has an official U.K. integration for a two gang zigbee dimmer, but don’t offer a three gang.

So that leaves Wi-Fi switches. There are lots of these, but most are not very well engineered and don’t have safety certifications. And they don’t have official integrations with smartthings. But there are two brands, Sonoff and Meross, Which are better engineered with more safety certifications and which have been fairly popular in the community. The Sonoff offers the most integration options, but only for some models and you have to have some good technical skills to implement it.

Otherwise, regardless of the Wi-Fi brand, you have to start looking for a “man in the middle” option. IFTTT is usually the easiest of those, but may only offer one way integration.

Thanks for the detailed response!

There are neutral lines at the switch iirc, but may not be for all the circuits (two were added at a later date), I will have to check. The biggest problem I face is getting a smart switch to fit the double size!

I wanted to avoid another hub for her, as more hubs means more points of failure. As I have to manage her smart home for her, it’s whatever makes my life easier in the long run!

On the subject of the micros, is there a preferred brand between Fibaro and Aeotec? I guess they are both natively supported in ST. Will they update firmware through ST if required?

Looking on Amazon, seems little difference in price between them.

You won’t find any decent smart switches to fit a double gang box in the UK… so micros are they way to go.

If the lights are on the same radial circuit, they can share the same neutral without any issues… one in the box is enough.

Fibaro dimmers will not work with traditional rotary dimmer switches, you will need to change the faceplate for something with 3 momentary (push to make) switches. For a double gang faceplate you will probably need to go for one of the grid systems like the range from MK.

How deep is the box? It’s theoretically possible to fit 3 micros in a double gang box, but only if it’s the deeper type. I once squeezed 2 micros into a 48mm deep single box.

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I’m already planning to change the switch, so that’s not a problem. Would a standard on off not suffice? I’ve seen various wiring diagrams of different setups, although the momentary switches do seem to be the way to go…

The box is the standard depth, not the deep one. I guess it’s possible to change, as it’s in plasterboard wall.

In a hollow plasterboard wall you can actually hang the modules inside the wall cavity behind the box… just extend the wires a bit and make sure you push back any insulation if any.

Momentary switches are best for the dimmer modules, as you can’t control the dim level with regular toggle switches.

Bear in mind that each Fibaro dimmer module has the facility to connect to a second ‘scene’ switch, which you can use to run automatons like ‘all off’ etc. You can do different things on switch 2 based on single, double and treble clicks / hold and release events.

In theory you could therefore make your 3 gang switch into a 6 gang switch (3 to control the loads, 3 to send scene ID’s to the hub), but I guess that might be a bit overkill and confuse your mum… perhaps just have on extra ‘scene’ switch per cluster.

That’s sounds like what I’ll have to do.

Would these be suitable?

https://www.screwfix.com/p/varilight-z2dg102srs-10a-2-way-off-retractive-switch-brushed-steel/38220

After looking at the MK ones, I think they may be too hard to press for my mum.

The 2 way and off switches (blind switches) will certainly work, but you would loose the ability to use switch 2 for scene ID’s (without also toggling the light when trying to send scenes)

I find that basic on/off retractive switches work best:

Single click - toggle
Double click - 100% brightness
Hold when on - dim up
Release and hold again - dim down
Hold when off - turn on at 1%

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https://www.varilight.co.uk/configurator/product.php?code=G100PS

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Great, I’ll see where I can get one of those from.

Thanks for your help :+1:

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I use ashdown home store a lot… prices are always good:

They do the full varilight range

https://www.ashdownhomestore.co.uk/varilight-powergrid-range-607-c.asp

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Hi,

You could try putting 3no retractive switches in a 2g frame (plenty of manufacturers) and then add a dimmer module at each light you’re controlling.

The added advantage of that is you will have a neutral at the light but rarely have them at the switch.

Try these, there sold as being able to be put onto other dimmer plates. No neutrals needed, I’ve just fitted a single and was easiest switch I’ve ever done

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Was going to mention these too :slight_smile:. Not that I like rotary :mask: but you can literally replace your old modules with these and continue using them.

So for push to make of centre off switches in the UK check out click and there mini grid range. I use the Deco range but there is loads of options and at a great price point. Your need to get from a wholesaler though.

https://www.scolmore.com/products/minigrid/

These are fully ST compatible?

Yea, just paired as zigbee dimmer
https://www.cwberry.com/Electrical-Supplies/Light-Bulbs/LED-Light-Bulbs/LED-GLS-Lamps/Aurora-AU-A1ZB2WDM1P-250w-Smart-Rotary-Dimmer-on-1-Gang-Plate_07102487.htm

Then these would be a far simpler option than fibaro micro dimmers. Think I’ll cancel the order and get these instead. Means I don’t have to change the back box and cuts down on wiring!

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