Staircase Two‐Way Switch

[SvladCjelli]

I have a light on the stairs with two switches: one at the top and one at the bottom. The bottom switch is also a double switch that controls the light in the back room, which works fine.

The problem is that while I can turn the stair light on with either switch, I can only turn it off with the same switch I used to turn it on. If I flip the other switch, the light stays on.

I've been going round in circles for hours and any advice would be greatly appreciated. Thanks!

Bottom

Top

 

[Murdochcat]

do you know where the old white cable joins the grey cable?

The 2G at the bottom needs 3 core and earth to function as a 2 way switch - so its a bit of a lash up.

 

[SvladCjelli]

Hey, thanks for your reply.

I'm not really sure where it connects, as I bought the house with the wiring already in place, and it just runs under the plaster in the wall.

So, based on what you said, are my only options to leave it as it is or rip it all out to replace the wiring?

Thanks

 

[ericmark]

The third wire down, is the permeant line, and years ago it was common to borrow that supply from another switch on the plate, this was OK when we had just one lighting circuit, although fronded on today as it can cause radio interference. However, when we started to split lighting circuits, that method could no longer be used. I am guessing that is the case with you.

I will guess this switch should be an intermediate switch, but this switch has different colours, so there is clearly more to find.

However, today we smart switches, so we don't need wires between the slave and master switch, so we can get it to work even with the lack of wires.

But to swap, you will need to test and find what does what. So the easy way out, is smart bulbs, never turn the lights off with the switch, but use voice or other remote controls. Switches like this can connect direct to the bulb (with a hub as well) so with the right smart bulb you can have multi switching without touching the wiring. Something for you to consider. Otherwise, you need to do some investigating.

 

[Jurassicspark]

The cables to the 1G switch are surface mounted, follow them and see where they go.

 

[securespark]

It's unconventional.

But I have seen a similar set up before.

The two together went to the switch wire on the landing. The strappers ran down to the downstairs switch. The feed was on the common.

You'd need to look in the landing fitting to see if there is a red and a black in the terminal for the switched live.

You'd also have to check that the red black from the landing going down is connected to the brown/ blue going to the downstairs switch.

Two big IFs.

But if those are the case, you could redo the connections at the bottom switch and make it work.

 

[securespark]

But the wiring is not the best, to put it politely.

 

[sparkwright]

What does the other switch on the 2 gang switch do?

It MAY be that the 2 gang switch is wired wrong - assuming the grey and white cables are simply joined together, it MAY be that at the 2 gang switch, it should be a case of the common getting it's perm live from the adjacent common, the brown in L1, and the blue in L2.

But it all needs testing out really.

 

[Ragnar_AT]

The downstairs switch has to be wired incorrectly, it only has two wires connected, any 2-way setup would need three. Considering how bad the newer wiring looks I wouldn‘t feel confident going wireless without fixing that lash-up. Time to lift some floor boards I‘m afraid.

 

[ericmark]

Once one looks at smart switches, two-way can be done with zero, 2, 3, or 4 wires between the switches, when wiring a machine, I had two wires, carrying 24 volts DC, which could go to 31 units, and each unit could switch 4 items. (ASii) And this did not use wireless.

But the cable was special, and also very expensive, so although it can be done, not really what we are looking for with domestic, ideally job one is work out what cables go where, one can get around the lack of cores, this shows how switches only have power, and can work as two-way, and I have already shown battery powered units.

I would agree, really best to work out what you have. And some smart devices are expensive. I had the same problem with my central heating, only 2 wires boiler to main house, and I wanted to control central heating and domestic hot water with just two wires, so I used Nest Gen 3, maybe not the best idea, but just pointing out there are ways around the problem.

So what we are looking at, is your skill. And cost. The simple way out, is employing an electrician, and clearly you don't want that expense, but how much are you willing to pay?

So with two buttons, and £60 will give you up and down stairs control, and you can even set it up as a two-way dimmer if you want. This

is cheaper, but you need to sort out the wiring, and the forum is full of requests for help with these systems, plus likely needs deeper back boxes, so still looking at around £25 by time you have fitted new back boxes, and also need to work out what goes where.

So what do you want to do? I am happy with no switches, I just use voice commands with Google Nest Mini's, same can be done with Alexa, my landing light should work with the old switches, and sometimes it does, but been using voice commands now for a couple of years.

I have a relay built into the lamp, in hindsight, would have been better with just smart bulbs, but what do you want? I used the smart button as shown for dinning room when temporary used as a bedroom for my wife, they were never used, work as a doorbell push button now, wife used voice commands, she has got use to "Hey Eric, make me a cup of coffee?".

 

[SUNRAY]

From your pictures and description; I'm making the ASSUMPTION you currently have this situation, I have omitted earth wires for clarity:

I suggest you initially follow Securesparks advice

It's unconventional.

But I have seen a similar set up before.

The two together went to the switch wire on the landing. The strappers ran down to the downstairs switch. The feed was on the common.

You'd need to look in the landing fitting to see if there is a red and a black in the terminal for the switched live.

You'd also have to check that the red black from the landing going down is connected to the brown/ blue going to the downstairs switch.

Two big IFs.

But if those are the case, you could redo the connections at the bottom switch and make it work.

The switch shown in pink being for your back room and working as desired can be ignored for now.

My guess: Somewhwere there is a joint between the red/black wires and the brown/blue wires, hopefully in the form of a proper junction box (or even an intermediate switch), although seeing the very poor way the downstairs switch has been wired I suspect the joint may be done to a poor standard.

If my assumptions and guess are correct; then I further assume that moving the brown wire from com TO L2 (on the downstairs switch for the upstairs light:

May make the system function as expected.



However as has already been stated by others:

But the wiring is not the best, to put it politely.

... Considering how bad the newer wiring looks I wouldn‘t feel confident ... without fixing that lash-up. Time to lift some floor boards I‘m afraid.

This really should be investigated properly, potentially you have a "borrowed neutral" situation which could cause problems in the future: Do you have 2 lighting circuit breakers (or fuses) in your consumer unit (a pic showing the circuit breakers would be useful).

Most of what I've written is basically reinforcing that previously posted by others, but worded idifferently.

 

[securespark]

We are all guessing here, but I have thought of another possibility.

That Volex switch position could have been an intermediate, with a 2 way at the end of the line.

Someone may have tried to adapt it to a 2 way?

It's anybody's guess!

 

[SUNRAY]

We are all guessing here, but I have thought of another possibility.

That Volex switch position could have been an intermediate, with a 2 way at the end of the line.

Someone may have tried to adapt it to a 2 way?

It's anybody's guess!

Agreed, I am certainly making assumptions and guesses but based on the acceptable operation of the second gang and description of the 2 way switching; I hope I'm not too far off.