Single switch to double switch (adding second light in same room)

hadley1 · Feb 12, 2021

Hi all,

As per the subject, I am looking to change an existing single switch for a bathroom to a double switch to control an additional light in the bathroom. I have looked at the wiring and there seems to be:

1. one feed (T&E) to the switch (i.e. no return for the loop so I imagine there is a junction box in the ceiling void?)
2. a 3c&e to the isolator switch and onto the fan
3. a T&E to the existing light

My question is if I add a double switch and wire as it is for the single, but then bridge the COM points between the switches with a live, then take a T&E (from the L1 on the second switch, neutral block and earth point respectively), will this work?

I imagine there is a junction box in the ceiling for the lighting circuit loop and then a feed cable has been taken down the wall to the switch and onto the fan/lights - does this sound right?

I have attached a photo of the switch in question.

Thanks!

westward10 · Feb 12, 2021

That is possibly end of circuit hence there is no apparent loop out. What you are suggesting should be feasible.

telectrix · Feb 12, 2021

you have neutrals in that switch. (in the choc block). all you need to do is bridge L fron exixting switch common to switch2, then take a T/E to new light sw/L and N. ( obviously take E also.)

hadley1 · Feb 12, 2021

Thanks both for the prompt replies!

Dave OCD · Feb 12, 2021

westward10 said:
That is possibly end of circuit hence there is no apparent loop out. What you are suggesting should be feasible.

But the switched live and neutral to the light isn't there at the switch, it might well be connected from the fan isolator though.

westward10 · Feb 12, 2021

Dave OCD said:
But the switched live and neutral to the light isn't there at the switch, it might well be connected from the fan isolator though.

It is. Top terminal line in and permanent line to fan, bottom terminal switched line to light and switched line to fan. Three neutrals, in, fan and light.