Upstairs/downstairs switch issue

[Jurassicspark]

You do need to have a (preferably low-impedance analog) meter available to check for
"Permanent" Line Voltage
AND
"Switched" Line Voltage"
at each of the six Switch-Terminals - in the four possible combinations of the switches.

A usual multimeter with a 10M ohm input impedance would do the job.

 

[ericmark]

I know the wiring shown is possible, so only three wires to each switch, but never seen it done before. Since there is a connection in the ceiling rose, the fault could be there. Normally we see 5 wires to one of the two way switches, so wired like this

so the com wire can't change colour, with the ceiling rose method colours can change, where it says extra joint in rose. So lets see picture of ceiling rose.

Using logic with light off only one wire on each switch should be live, so we know that wire will not go to com, (note switch markings some time call com S1 if so there will be a S3) but that leaves us with two wires and no easy way to work out which of the two should be com. We would normally ensure same colour both ends, so should be yellow with both switches which is what you have, so theory it should work, so either a wire is open circuit, or colours swapped in ceiling rose.

 

[SUNRAY]

I may very well be wrong on this one but I can well imagine this being a classic case of either the red or blue wires not being continuous (broken) or screw clamped onto insulation:

The other which I feel is quite likely is the red and yellow wires have been transposed:

Instead of being this:

It's this:

It makes me wonder if the switches were removed without noting the wiring and then replaced using the classic colour combination of the conversion method.

 

[SUNRAY]

Has any attempt been made to look in the kight fitting/ceiling rose at the wiring?

 

[Jurassicspark]

Without a multimeter no one can assume which wire does what.

 

[Tait1983]

Thanks for the input, the switches were definitely removed without the wiring being noted and then my dad replaced, I'm assuming, as you said using the normal wiring colours. I haven't look iat the ceiling rose, but next time I'm over I will do this and hopefully get to the bottom of this.

 

[SUNRAY]

Without a multimeter no one can assume which wire does what.

Anyone can assume anything, whether they are right is anyones guess.

All I'm doing is applying a little logic to the sitaution, my first and third sketch both give those fault conditions and I have certainly encountered both

 

[FrodoOne]

The red, blue and yellow cable is for the stair lights, which is wired identical to the single switch upstairs(this is the issue, I can switch the stair light on from downstairs, when I go upstairs I can switch it off, BUT, if I then want to switch it back on from downstairs it doesn't work, unless I switch it back on from upstairs first. I'm completely lost with this to be fair.

IF you have changed nothing, (and it worked, previously) it MUST be a loose connection - somewhere.

(RE)-Read Post #14 - and act upon it.

 

[SUNRAY]

IF you have changed nothing, (and it worked, previously) it MUST be a loose connection - somewhere.

(RE)-Read Post #14 - and act upon it.

I think you'll find something has changed in as much as:

..., the switches were definitely removed without the wiring being noted and then my dad replaced,...

 

[Murdochcat]

Thanks for the input, the switches were definitely removed without the wiring being noted and then my dad replaced, I'm assuming, as you said using the normal wiring colours. I haven't look iat the ceiling rose, but next time I'm over I will do this and hopefully get to the bottom of this.

So your best course of action may be to get a spark in and get your dad to pay his bill

 

[SUNRAY]

So your best course of action may be to get a spark in and get your dad to pay his bill

Or he could ask for help on a DIY help forum

 

[FrodoOne]

Or he could ask for help on a DIY help forum

And - act on it.

 

[SUNRAY]

And - act on it.

Which I believe Is happening, but it sounds like his father property so there will likely be some to and froing and delays.

 

[Tait1983]

So your best course of action may be to get a spark in and get your dad to pay his bill

Here Murdochat, see if you've nothing proactive to state then stay the f**k out of this thread. My dad did the work when he was still living and I'm trying to put it in the correct working order for my mum, so either post something that might actually f**king help or get lost. As for all the others in the thread, I really appreciate your help with this, and when I do get back over to the property I most certainly will act upon all of the suggestions and hopefully put it right. Thanks again to all of the actual productive people on here that want to help others that don't have the full technical knowhow.

 

[securespark]

I understand you have been bereaved, but please don't be abusive.