DIY Doctor UK DIY Forums

I was up in my loft today, removing some old water tanks, as I now have a combi boiler fitted. Running along the side of one of the joists is a wire that is connected into four terminal blocks/ It looks like they are joining the two wires together. The cable is four core, red, black, yellow/green and a bare copper one. Any idea what it could be for. It seems to go down the wall to the landing light switch. In total there are four cables going down the same hole, some are thinner so I presume they would be the red and black that go to the switch and lamp holder. However, do you think this copper wire should be insulated and if so, what colour should be used, as I would not want to put anything on it that may confuse anybody in the future. The house was built around 2000, so it is not an old one that has been re wired.

I would suspect that what you think is black is infact blue, and the one you think is yellow / green is infact just yellow. This being so, it would mean the cable is a 3 core and earth which is used for two way switching. (One switch on the landing, the other switch in the hall for the same light) The bare copper one being an earth should have green / yellow sleeving.

Thanks Mr White. For some reason I woke in the night thinking that I had written the wrong colours down (odd mind!). That would make sense it being around the switch area. I think I may have some sleeving somewhere, I will put it on. Thanks for your help.