two-way switch problems

[JRo]

Hi there, am new to electrics and wiring - help is welcome! Just bought a house, and the two switch, two way switch from hallway to stairs does not work - there are two switches downstairs (one successfully operates the downstairs/hall, the other does nothing) and one switch upstairs (successfully operates the landing).

Have made a basic diagram below - hopefully clear - there is no third(fourth) wire - only the red and black for both circuits (and earth). Any suggestions on how/if this can be wired correctly would be great!! (there was an existing red wire connecting the COM ports - what is this for??)

PS - electrician already been in to fit various bits (did not realise about the switch) but will come back and test electrics soon....rather not pay again for him to do something which seems it should be so simple!!

Thanks!

View media item 22439

 

[ban-all-sheds]

Are you sure that the COMs only had that link wire in them - none of the other conductors was also there?

Your diagram shows "how it was before", and yet you also say "one successfully operates the downstairs/hall, the other does nothing", but that looks impossible.

Sure it wasn't wired like this:

What wires are present at the landing switch?

Do you have a multimeter?

 

[electronicsuk]

Your diagram shows "how it was before", and yet you also say "one successfully operates the downstairs/hall, the other does nothing", but that looks impossible.

I suppose it would be possible depending on the position of the other switch, although you'd think the OP would mention that.

 

[ban-all-sheds]

If it depends on the position of the other switch then the other switch would not do nothing....

 

[JRo]

Cheers for reply....my diagram was definitely correct - I even took a photo (but have not got camera with me to upload it) prior to removing fully from wires just in case! I have not removed/checked the upstairs landing switch wires - on putting back the bottom switch with same connections, the top light works from the top light switch (but without the bottom switch connected it does not work at all). The top light works irrespective of the position of the bottom switch, but bottom switch needs to be connected...

Not sure what a multimeter is? Suspect I dont have one though!

I suspect our plasterer took the switch off and reconnected it wrongly....but dont really know! My diagram does not seem to fit with any pics online, and have no idea why the two COMs are permanently connected in this switch.

I have bought a new switch, just in case is something to do with this, and will attempt to fit this tonight...

 

[ban-all-sheds]

on putting back the bottom switch with same connections, the top light works from the top light switch (but without the bottom switch connected it does not work at all). The top light works irrespective of the position of the bottom switch, but bottom switch needs to be connected...

That makes sense, it's the bit about the downstairs light working OK that I can't see.

Not sure what a multimeter is? Suspect I dont have one though!

You don't.

I suspect our plasterer took the switch off and reconnected it wrongly....but dont really know!

Ah.....

My diagram does not seem to fit with any pics online,

That's because that way of wiring it up doesn't work.

and have no idea why the two COMs are permanently connected in this switch.

Because the 2-way switching you have for the landing light is like the top left diagram here: http://www.diynot.com/wiki/electrics:two-way-lighting and the switch on that side is getting its permanent live from the other side.

http://www.diynot.com/wiki/electrics:lighting

I have bought a new switch, just in case is something to do with this, and will attempt to fit this tonight...

That will do no good at all - it needs to be connected as per the drawing in my first reply.

Are your upstairs and downstairs lights on separate circuits?

 

[JRo]

cheers - will try connecting as per your diagram and see how that works. I believe they are seperate circuits - seperate fuses in the distribution board (although the upstairs landing light is on the downstairs fuse). will have a look later when i get home.....let you know tomorrow!

 

[ban-all-sheds]

Please make sure you turn off both lighting circuits before working on either of them.

You have a borrowed neutral: http://www.diynot.com/wiki/electrics:sneutral

PS - electrician already been in to fit various bits (did not realise about the switch) but will come back and test electrics soon....

Ask him to sort out the borrowed neutral while he is there. The upstairs light should have its live and neutral from the same circuit.

...our plasterer...

That may turn out to have been premature.

 

[JRo]

your lighting diagram worked a treat - both lights working as they should! Many thanks!

 

[ban-all-sheds]

Don't forget to get that borrowed neutral sorted out - it's a Bad Thing™

 

[SUNRAY]

Don't forget to get that borrowed neutral sorted out - it's a Bad Thing™

Its a very bad thing and does need sorting. If t is a borrowed neutral, and I'll put money on it that it is, your electrician should have found it and sorted it when he did his testing.