2-way smart lighting guide

How do I fit a two-way switch? 

Two-way wiring can look very complicated at first, however, as long as your lighting is working well on your manual switches, it should be simple to swap to Lightwave’s Smart series.

If you’re not comfortable doing this yourself then please consult a qualified electrician.

Before you start 

Shut off the power to the lighting circuit. Unscrew the faceplate of the switch to remove it from the back box. Take photos of the existing wiring at the back of each switch as it can be very useful to refer to at a later stage. Try to capture which terminal goes with each wire.  

Two-wire or three-wire system 

It is important to understand what system you are working with and it’s not as difficult as it may sound. Look at the back of each switch: you should see wiring terminals labelled ‘L1, L2, and C’. If both switches have no more than one wire fitted in to each terminal then you have a three-wire system. If one of the switches has more than one wire in both the L1 and L2 terminals then you have a two-wire system. Once you have identified your system, please follow the steps in the section below that applies to your set up.

Two-wire system 

For both switches, move all wires fitted to the L1 to the L terminal on the Lightwave switch. Move all wires fitted to the L2 to the X terminal on the Lightwave switch. Wires in the C terminal are not required and can be safely terminated or removed altogether. 

Three-wire system 

At the first switch, move all wires fitted to L1 to the L terminal on the Lightwave switch. Move all wires fitted to L2 to the X terminal on the Lightwave switch. Move all wires fitted to C to the L terminal on the Lightwave switch.

At the second switch move all wires fitted to L1 to the L terminal on the Lightwave switch. Move all wires fitted to L2 to the X terminal on the Lightwave switch. Move all wires fitted to C to the X terminal on the Lightwave switch.

What if I have more than two switches in the circuit? 

This is typically known as intermediate switching. It’s largely the same as two-way switching, but there is a specialised switch in the middle and additional wiring. You can spot this switch by looking at the back of it - it will have two sets of L1 and L2 terminals.

To add a Lightwave dimmer to this set up, you still need to follow all the steps above, but when you come to this particular switch, you need to move one set of L1 and L2 wires to the L terminal on the Lightwave switch and then move the other L1 and L2 wires to the X terminal on the Lightwave switch.

Finally, you need to create an ‘automation’ in the app to group these devices together so when one Lightwave dimmer is switched the other will too. To do this, you will need to open the app (let’s assume you have already registered your Link Plus and added your devices), click the ‘+’ symbol, select ‘Automation’, and choose ‘Two-Way Switching’. From here the app will take you through the set up steps.

Do you have further questions? Visit our support centre.

Need help? Lightwave provides a complimentary home consultation service.