So I’m looking for something like the sonoff zbmini2. However my switches don’t have neutrals (in the UK). I’m also already using smart bulbs so don’t want the switch to actually turn the light on and off.
I need these just to detect the position of the light switch (on or off).
I’ve seen sonoff has a version for no neutral and a version with neutral that can do no relay, but there’s no that does both.
Anyone done anything similar and have any recommendations? Could I use the no neutral sonoff and just stick some wagos in so the light is always on?
No.
The “no neutral” Sonoff switch requires the load of the downstream device. The device itself (a light) is connected to neutral and there will always be some leakage current through the device. Since the Sonoff switch only draws a few microamps, it can rely on this leakage current for its “neutral”, completing the circuit.
If you hard-wire the downstream device to the line so that it is always on, there will be no leakage current for the Sonoff to complete its circuit. It’s dead.
The best solution is to pull a neutral wire to the switch box.
I just install modules behind the light fitting or the ceiling rose (I use larger ones to fit the module in), that way you have access to L, N, switch and load if needed
If you use Shelly in the light fixture you remoteley and by using the switch to turn the light on or off BOTH work seamlessly together, just set the Shelly relay to “edge” mode. Any change to the switch - just turns the light to the other state. For example, even if the switch is off, you can turn it on remotely, and then when the light is on but the switch is in the off position, turning the switch to the off position would turn the light on, etc. Very clever.