Hi guys,
I was looking at installing one of these ZBMINIL2 devices in the stairs of the folks house last night.
Following the diagram provided by Sonoff I don’t see how this can be achieved in the folks setup.
I have attached a diagram of how the wiring looks on the folks stairs and also the diagram Sonoff provided for 2 way wiring.
Anyone any ideas how this could be wired or if it’s even possible?
Thanks,
Mac
Cut red cable from Switch 2 to Bulb
Connect red cable from Switch 2 to S2 (ZBMINI)
Connect red cable from Bulb to L Out (ZBMINI)
Draw new red cable (L in) to (L in) (ZBMINI)
Thanks for that but I’m still not fully sure.
So, are you saying I need to get a new constant Live in, from downstairs up to the switch upstairs and this will go into L In on the ZBMINIL2?
That’s correct.
That is going to prove quite difficult to do I feel without major surgery to the walls…
Thanks for the heads up on this…,
Yes, this is what I have in mind.
BUT do not forget to connect the Live wire to Switch 1 too.
Really, live to switch 1?
That doesn’t seem right, you would then have a live wire going to S2 on the ZBMINIL2 
According to “your” wiring diagram, the Live wire goes to Switch 1 and L in.
I attempted to wire the stairs switch like this today but it’s not working I’m afraid…
I have the wires connected as above from what I can make out but switching the rocker switches doesn’t trigger the relay…
I added a new live wire and connected it to L in. I connected the ceiling light to L out. I have left Switch one as it was but now I have added a new wire from where the ceiling light was connected to Switch 2 now connected to S2 on the ZBMINI.
Is this correct?
That is pretty much how I have it wired but only difference is that I have a new wire coming directly from the fuse board to L in instead of branching off from the Live going into Switch 1.
Would the branch off make any difference, both should be constant live feeds?
I think the way you conceived and created it also works.
I thought it should be matching the diagram that Sonoff produced but it’s not working, the wall switches just aren’t triggering the relay…
I think I may need to contact Sonoff to see what they reckon, something just isn’t right currently…
Does the ZBMINI turn on and did you succeed in make it join your network?
If not, it might be a power problem. Try using a classic luminescent bulb and see if it now works.
If it joined your network, it might be a switch problem. Try toggling it through home aasistant and see if it works.
It could also be that you’re tripping an earth leakage circuit breaker when you connect the new live wire to the ZBMINI. Make sure that it shares the same earth leakage circuit breaker as the live wire connected to the downstairs switch.
Hi there,
Thanks for the reply.
Yes, the ZBMINIL2 is powered on and connected to HA fine and can be switched on via HA and manually via the button on the ZBMINIL2 itself.
It’s just the switches connected to S2 that’s not triggering the relay for whatever reason?
I’d check the voltage of the red line coming from the upstairs switch and see if it toggles when you flip either switch.
My guess would be you’ve made a mistake in wiring the upstairs switch (in networks like these the switches can be complex).
Yeah, the voltage does toggle when I flip Switch 1 & Switch 2 so I think that bit is ok…
I’ve obviously made a mistake somewhere, or perhaps I’ve a faulty relay, only thinking that now…
I’ll have to rethink it again tomorrow perhaps!
Thanks again
Hi guys,
Just a quick update, I got it sorted 
The wiring was fine, it was just a faulty relay. I switched it out for another one and away it worked straight away.
All is going fine now apart from some pretty problematic Sonoff Occupancy sensors that I just can’t get light levels from, one for another day.
Thanks for all the help on this one, really appreciated 
Glad to read that you were able to solve it.
You do not assume that the relay could be defective.
