Still struggling with 3 way circuit

Hello Everyone,

I was wondering if vision dual relay switches can be used in a 3 way circuit. If yes, some guidance would be much appreciated. I understand 3 way circuits but cannot wrap my head about integrating a relay switch in there.


I would wait for someone with more electrical knowledge to chime in but I don’t think you can do it with a simple relay. If you want your switches to still work I would imagine putting a relay in the mix would turn your 3-way circuit into a four way circuit which I think would require whole new switches and an additional wire, plus a special relay (or series of relays) to handle that.

Would it be easier to just turn it into a regular circuit and then throw in the relay?

Perhaps but I’m not an electrician. It might be easiest to find z-wave (or your technology of choice) 3-way switches, or put in two single pole z-wave switches but leave one of them disconnected from the light and use rules in openHAB to flip the other one when the disconnected one is switched. This would move the 3-way logic into openHAB.

if you have a link feel free to share.

also in case I add the relay to the light instead of the switches, would it still pose the same problems?

I’m just going off of my experience and supposition. I have no links but a quick google shows a ton of 3-way z-wave switches for sale.

No just adding a relay at the light probably won’t work because the relay would only work if the switches are on. Otherwise there is no power at the light to relay.

While this is possible you run into the issue of lets say the relay is on switch 1. If you turn switch 1 off using z-wave and then use switch 2 to turn on the light the z-wave is still going to read that it is ‘off’. What I think you are after is an auxiliary switch,

See this diagram - taken from

I highly recommend that you use the ground if it is there, I have read some places that say the auxiliary switches will not work without a ground wire.