I know this has been posted many times before but I can't find my particular problems' solution, so sorry but I need help. I am trying to replace my double light switch in the hallway that operates the hall light and also the upstairs landing light, the switch in the hall is 2 way, the landing is 1 way. After mucking around for hours I have the 2 way switch wired up so that the downstairs and upstairs lights work from the hallway, but now the switch on the landing upstairs doesn't switch the landing light off! the wires for the downstairs are the usual, 1 red and 1 black from one cable, then 1 red, blue and yellow from the other cable. The upstairs landing has the same number and colour of wires plus an extra earth.
The thing that is most confusing is that the new 2 way switch shows L1 as being the Comm too, but the upstairs landing is wired with the red & black to L2, the red and blue to L1 and the yellow to Common, it doesn't have an L3??!! Help anyone before I go mad please :0)