Shelly 1L - UK 2 Way Switch (3 Wires in each switch + earth)

Hello All,

I am not sure about forum etiquette, so apologies if i have posted in the wrong place but i thought it would probably be best to start a new thread for this.

I have purchased the Shelly 1L and Bypass for a 2 Way Switch, single light, setup and have fitted the bypass without issue. However, the wiring in both switches are as shown in the attached image and I have wired in the shelly 1L as suggested by Dimitar Dimitrov, and shown in the image below. Sadly though, at this stage all I can do is turn the light on/off via the shelly and the switch it shares a wall box with. If I then flick the other switch on/off it cuts power to the shelly and the switch in the wall box with the shelly.

Unfortunately i do not know the circuit is wired in the walls, all I know is what i have posted above and that, before installing the Shelly, both lights would alter the state the light was in when flicked - regardless of the current state of the other switch or the light itself.

Any help/insight here would be appreciated. All I can think of is that the light itself might be in between the two switches in the circuit and that putting a Shelly 1 in the ceiling with the light might work. However, I have the Shelly 1L already and would prefer to find a solution that utilises that if possible.

Thank you all in advance and i look forward to hearing your suggestions.

Hello, thank you very much for your message and willingness to help out.

I have prepared a wiring diagram showing the switches and the lamp as best I can as I do not know how the circuit is laid out in the walls and celling. The original circuit contains Switch A, Switch B and the Lamp. Switch C is a switch for another lamp in a separate room, but I have included it in this diagram as it shares a wall box with Switch B. This diagram is as follows:

Photograph of Switch A before installation of Shelly device:

Photograph of Switches B and C before Shelly device installation:

I had attempted to install the Shelly 1L at the same location as Switch A, leaving the wiring as it was in the wall box for Switches B + C. I have since uninstalled the Shelly and so have not got a photograph of the device installed. However, the diagram below shows how I intergrated it with the existing circuit:

Looking forward to hearing back from you and thank you in advance for your assistance.

My apologies for the delay between my responses, I have been at work.

I have done some investigating and it would appear that the Live wire is coming in to Switch A and the Switch Live wire is from Switch B. However, I need to mention that the diagrams I have sent have Switch C and B labels mixed up. The switch labelled Switch C is what I have been referring to as Switch B in our conversations (including above) and the switch labelled Switch B is what I have been referring to as Switch C. My apologies for this mix up.

Thank you again. I hope this makes sense. Please let me know if you require any other information.