How to wire a Sonoff ZBMINI L2 Extreme for EU 2-way Light Switches

Hey everyone,

I have 2-way no-neutral regular/dumb switches in my home in Croatia. Their wiring in the wall box looks like this:

How do I add ZBMINIL2 to the picture, i.e., how do I wire it such that I have 2-way switching that also supports control of the light via Zigbee? Do I have to place ZBMINIL2 to both of the wall boxes or is it enough to wire just one?

I already have a Zigbee2MQTT network with around 20 devices so the basics in that regard shouldn’t be a problem.

Just one, replace with momentary switch so you can use existing wires

Otherwise you’ll need to extend another live wire going to the 2nd switch

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There is no EU standard on electrical wiring and installation.

But you might also have the option to place the shelly in the outlet instead.

Thank you for your diagrams, @ferbulous ! Can you also annotate the wires?

@WallyR , what exactly do you have in mind when you refer to “the shelly”?

Keep in mind that the dimensions of a device to got into a wall box are quite important. By not thinking much about it the last time, I got myself a ZBMINI, but it didn’t fit into my wall box. ZBMINIL2 is smaller and it should fit, though.

Sorry, I mix up Shelly and Sonoff often, because they are quite alike in my world. :slight_smile:
The same applies to the Sonoff ZBMini, though. It can be wired up in the outlet too, if the wires there are better suited and the room is there.

Sure, i’ll just use the label from your switch, if you’re replacing with momentary type, remember to change the switch mode on the zbmini l2


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How is the momentary switch setup supposed to work here? Ie. you always have one of them in open state, so you should never get anything on S2…

And why wouldn’t those work in this situation:

I’m not entirely sure, probably detects input change when the sonoff zbmini l2 is set to push button mode (default is rocker)
It just works though

Ahah, it’s slightly different from the diagram you have above (s2 is connected in between the switches and gets live when either is pushed. So there is a flip-flop inside the switch that remembers the state, and this is what this mode is about…

Interesting, thanks! :slight_smile:

The reason why I was reading here is that I am trying to understand what happens if the switch is either disconnected from the Zigbee network or dies completely…
I would expect that in this situation, the state is local, and the switch should keep working as-is even with no zigbee network.
If it dies for whatever reason, your switches stop working, but I don’t know if there is any wiring setup where they do keep working…

Any thoughts?

Woops, I need to fix that, it’s the same like in the video
@mdimjasevic please ignore previous diagram

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Yes, it does continue working as normal if zigbee network/coordinator goes offline

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Thank you again, @ferbulous !

I do not really have an option of running a new wire from one switch to the other. It would be very unpractical because I have a handful of 2-way pairs of switches that would have to be modified this way.

Is this something where two ZBMINIl2 devices can be used, one at each switch, that synchronise their state in software (e.g., in Home Assistant)?

No, just one zbmini L2 for each pair of switches in a 2 way wiring.

I did the same for a few of my 2 way switches. Without new wires theres no way. Also 2 zbminis wint help anything you need a permanent live wire and the wire that fonnecte to your light in one place for the ZBmini to work which currently you dont have.
It’s not a lot of work, just a few wire nuts/clamps and two short leads, but you have to replace the rocker switches.
Once wired, power the zbmini and press the button on the mini L2 three times to switch to momentary switch mode.

Thanks to all contributors to this thread I was able to smartify my existing 2-way switch, powering my hallway lights.
A couple of notes:

  • It sort of bothers me to look at this bulb with the single wire so I’m adding my own diagram

  • I was taught lights don’t have a live and a neutral wire, they have a live and a ‘lamp’ wire, and the huge difference is that you should never ever break a neutral. Фаза and Лампов on my diagram

  • I had a spare Live at my 2nd switch which made installation simple, however it was coming from a 2nd breaker (same phase, different breakers). Technically not an issue, but I don’t feel proud about it. Also, killing this 2nd breaker breaks the 2-way switch circuit, so I would assume if the Sonoff ZBMini goes dead for whatever reason (not Off but like dead) it will mean I have no lights. Which isn’t good.

I’d love to see other implementations.

Hi, this is how I managed to use the ZBMINI for 2-way light switches in my apartment: Hallway lights automation - Paco's Smart Home

I hope my post is useful.

Kind regards,

The only way without new wires is if you happen to have the relevant wires at the ceiling rose. Then you can put the zbmini at the light fitting instead of the switch.

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I have this kind of wiring for my two way switch and I have been struggling to add a ZBMINI L2 to this system. Is it even possible?

Hope somebody can help!


exactly the same setup as my diagram two posts above, just try to rotate one of the pictures upside down :slight_smile:

Thanks for the answer! I figured it out and had to rewire some of the connection in the selling but now it is working!