Shelly Dimmer UK wiring

Good evening !
Looking for some help on possibly adding some Shelly dimmers Into a couple of rooms in the house.

Last year I updated all the wiring and switches in the house and every room now has led dimmable down lights and all the traditional ceiling roses have gone and have been replaced with junction boxes As shown below.

I want the Standard on/off light switches to stay as normal not for the function of dimming, I only want to dim the lights via the Shelly app. So can the Shelly dimmer be added to this wiring and the junction box ?

Many Thanks

Hey Simon and welcome to the community :partying_face:

Obvious disclaimer first; those things should only be installed by a certified electrician, I’m not one of them.
The simplest way to achieve this would be to wire the circuit as specified on the shelly website.
Wire the switch into the relay, this way you can also control the light via the switch and the app at the same time, also you can set up the switch as an input for automations and stuff, there’s no real downside there.

If you don’t want that for some reason, you could just wire the switch in series with the light. So instead of wiring it into the relay you’d:

  • take the hot wire of the switch into the output of the shelly
  • connect the neutral of the switch with the hot wire of the light
  • connect the rest of the neutral lines together

Be aware that with this approach you can’t control the lights unless the switch is in the “on” position, which makes the shelly kinda useless.

Yes fairly straighforward.


Remove the 2 wires from the left connector of your junction box, wire the switch live (blue with brown sleeve) to the “I1” input, and the light live (brown) to the “O” on the shelly. Then, run brown wire from the 2nd connector in your junction box to the “L” connector on the shelly. Lastly connect a blue wire from your right hand side connector to the “N” connector on the Shelly

Note, shelly dimmer 2 has slightly different labelling, the switch would go to “SW1” instead of “I1” and you dont need a neutral to the shelly

Many thanks for your reply, it’s not as bad as I thought then, I’m pretty good with wiring and everything not sure why the wiring for the Shelly has been throwing me off !

What’s the difference between the first Shelly dimmer and the Shelly dimmer 2 ?

Many thanks.

I think its mainly the fact you don’t need a neutral so you can install it at the light switch

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Hi all, so I’ve installed the dimmer all works well, on the settings would you recommend leading edge or trailing edge ?


Give them both a try and see what you prefer. I personally prefer to have the switches pointing down when on, so sometimes need to switch down then up do turn it off. You can have it switching on either position as well. Can’t remember which is which…