enter image description here hi all, what have i done wrong? I replaced like for like (or so i thought) and the light won't work?

Thanks in advance

  • 1
    I've been staring at it, it looks mirror-image symmetrical! And correct, I cannot see where it wouldn't work. The light switch is on, yes? (For the Yankees, the wires in the wall are old work, black=neutral except one is a switch loop of course. The lower wires are new Eurocolors, blue=neutral.) Jun 18, 2016 at 19:55
  • A single photo is useless. Tell us what the connections previously were: which leads were the supply and which the return. What does "not work" mean? Have you tested the bulbs? Switched from 120V incandescent to 12 V LED? and so on. Jun 18, 2016 at 20:06
  • 1
    @CarlWitthoft: That looks like a standard UK 240V AC ceiling rose. Plugging 120V or 12V devices into it might be a bit too exciting. Jun 20, 2016 at 15:06
  • One of those black wires should have had a red sleeve or red tape on it. Did anything like that fall off? Jun 20, 2016 at 15:07

1 Answer 1


what have i done wrong?

Your wiring looks correct for the last light in a UK radial lighting circuit wired with the connections in the ceiling rose.

See Ceilling light wont switch off after a new installation

You could

  • Check that all the screws are fully tightened down.
  • The circuit-breaker in the consumer-unit has not tripped out (or fuse blown). This might not always be abvious in daytime.
  • There is 240 volts at one of the red wires.

For suitable voltage tester, see When doing electrical work, what do I use to check wires are safe?

Obviously, you need to take extreme care when working in the vicinity of live 240V circuits.

There are three common ways to wire lighting circuits in the UK (in order oldest method to newest)

  • wiring is connected in junction boxes under floorboards or hidden in the loft/attic/roofspace.
  • wiring is all connected in the ceiling roses (as yours appears to be)
  • wiring is all connected in the backbox behind the switch.

Yours might be like the last but with two lights controlled by one switch. In which case the wiring you show would be incorrect. Since you rewired like-for-like this is very unlikely.

See Lighting Circuits, Part 1, John Ward

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