2 Way Switch help! One switch immobilises the other

[WillShill]

Hi All,

I am a DIY'er renovating my 60s built house. I have been adding sockets myself and fitting new lights with no problems so far until I try to replace the 2 way switches at the top and bottom of my staircase. I just want to change the switches and keep the existing 2 way circuit in place.

The switches I have removed are old metal ones (terminals unlabeled) and I have replaced both with 2 way plastic switches. Although I have replicated exactly how I removed the old ones, I have an issue where each switch works ok individually, however when one is active, the other is immobilised.

Here is a description of the wiring. Socket 1 (upstairs) has 3 core blue yellow and red plus 2 core red and black. Socket 2 (downstairs) has just 3 core blue yellow and red. On both sockets I have connected the 3 core reds to coms, Blues to 2way and yellows to 1 way. In Socket 1 I have connected 2 core red to the 1 way terminal, and 2 core black to the 2 way terminal....following diagrams and videos online.

Where have I gone wrong? I read that in my instance the 2 core supply may be a switched live??? This is where I get lost. Help would be much appreciated.

Thanks!

 

[MJPD29]

Call in an electrician, how have you tested and certified for all the new sockets and lighta you've added? Do you have appropriate testing gear for all the work you have undertaken?

 

[telectrix]

OK. in the downstairs switch wire the 3 core any way you like. then in the upstairs switch wire the other end the same. e.g red to C, yellow to L1 and blue to L2.then the twin red/black go 1 in L1 and 1 in L2, either way round. ( I'mm assuming to understand L1 as 1 way,L2 as 2 way. )

make sure cpc's (earths), if present, are terminated into the metal back boxes

 

[westward10]

February must be the month of change my two way light switches

 

[sparksburnout]

You say you have been adding sockets with no problems, so far. Is this as in nobody got a shock or worse yet? How have you been testing your additional sockets?

 

[buzzlightyear]

I cant wait for the bank holiday's ,for this forum will get a lot of can I.

 

[WillShill]

OK. in the downstairs switch wire the 3 core any way you like. then in the upstairs switch wire the other end the same. e.g red to C, yellow to L1 and blue to L2.then the twin red/black go 1 in L1 and 1 in L2, either way round. ( I'mm assuming to understand L1 as 1 way,L2 as 2 way. )

make sure cpc's (earths), if present, are terminated into the metal back boxes

This is exactly what I have done which is why i am baffled as to why it doesn't work....

 

[shaun1]

So, when the upstairs switch (with the 3 core and 2 core?) is in 1 position, the downstairs switch can control the light, and when the upstairs switch is in the other position, the light remains off? If so, it sounds like either the yellow or blue cores are damaged (maybe snapped where you have bent them in the back box) or badly terminated. The quickest way to find the fault would be with a continuity tester.

As others have said, it would probably be wise to get an electrician involved sooner rather than later. You don't sound 100percent sure you know what you are doing. It can be very easy to follow a guide and match up the colours etc, but there are a lot of other considerations to make, especially with adding sockets. It may well work, but you need to be satisfied that it is safe.

 

[robd]

Something is obviously wrong so options are 1/ keep changing them round till it works or 2/call an electrician who will probably sort it in about a minute

You probably read up on what you are allowed to do as a diyer as well just to cover yourself

 

[Adam W]

This is exactly what I have done which is why i am baffled as to why it doesn't work....

The way you've described it should work. Try switching the light upstairs, then downstairs, then upstairs again, then downstairs again. Failing that try posting some pictures.

 

[telectrix]

The way you've described it should work. Try switching the light upstairs, then downstairs, then upstairs again, then downstairs again. Failing that try posting some pictures.

jeez, OP's legs will be huting after that. time to sit down, have a beer, call in a local spark, give him a beer. job done for <£40.

 

[MJPD29]

DIY sparks are my favourite. Endanger themselves and their family to save a few quid but most importantly give us a good laugh on here

 

[Octopus]

All I can add is that DIY shops must be selling lots of new switches at the moment!

 

[telectrix]

thing is... DIY swapping of accessories and minor suchlike jobs should get advice how to do where needed. changing a light switch is not rocket science. it's when DIYers get out of their depth that it's time to call in a sparks.

 

[SJD]

Despite your description of how you connected the "Switches" (not sockets), it sounds like you have connected either the live or switched live of the 2-core to the wrong switch terminal upstairs.