Lighting didn't come back on

[Mander]

I turned off the power to the lights in one room while I removed the lamp shades to clean them (they unscrew from the socket and I didn't want to accidentally stick my finger in it). However after I put them back together and flipped the switch back on, the lights I actually worked on came back on but the ones in the next room did not. I've tried turning them off and on again but no dice.

Any ideas? The consumer unit was replaced about 5 years ago and at the time got a full EICR, which didn't show any problems.

 

[terryplumb]

A few possibilities, if you moved the light fittings base whilst cleaning you may have loosened a wire within.
Or by coincidence ,there is a loose connection, or the switch has failed in the next room . Has the next rooms bulb failed ,what type of light fitting does it have ? Other possibilities exist but the above are the first things to rule out .

 

[Mander]

The two lights I moved around came back on, but the two I didn't touch in the next room did not. They are all standard cable-dangling-from-the-ceiling type with a bayonet fitting, and they all have LED bulbs that are relatively new. I just tried swapping the two that didn't come on with a new light bulb and that didn't help.

 

[333rocky333]

Often the power to the third room comes from the second room via the round bases mounted on the ceiling, it is quite common for a cable to come adrift if it was loose in the first place, usually after its disturbed

 

[terryplumb]

You will need to do some investigating. Turn off mains power first ,check for loose wiring connections at the switch,and the light fittings at the ceiling. If all looks well,you will need some electrical testing instruments to do further checks .

 

[JohnD]

It's probably a loose connection in a ceiling rose. After you have turned off the power at the CU, you can usually unscrew the dish-like cover by hand and check tightness of the screws or misplaced wires. It can be in the room with the non-working lamps, or in the next room on the circuit (likely in your case as they have been recently touched).

Note that turning off the light switch does not make lighting fittings safe.

 

[Mander]

Sigh, sounds like a daylight job. I probably ought to hire someone as I'm not very experienced with this sort of thing but I'll turn off the power and see if I can see anything obvious in the morning.

 

[JohnD]

Photograph your ceiling roses and we can give you some tips.

Also photograph your consumer unit and the cables around d it to give clues of the wiring age and quality

Examples:

Ceiling Roses

 

[FrodoOne]

It's probably a loose connection in a ceiling rose. After you have turned off the power at the CU, you can usually unscrew the dish-like cover by hand and check tightness of the screws or misplaced wires. It can be in the room with the non-working lamps, or in the next room on the circuit (likely in your case as they have been recently touched).

Note that turning off the light switch does not make lighting fittings safe.

See https://flameport.com/electric/lighting_circuits/lighting_ceiling_rose_looped.cs4

 

[Mander]

Photograph your ceiling roses and we can give you some tips.

Also photograph your consumer unit and the cables around d it to give clues of the wiring age and quality

Examples:

Ceiling Roses

Roses are all this type. The ones with screws are the ones that aren't working.

I went back through my files and the consumer unit replacement and EICR happened in 2019. The actual wiring is all roughly 1980s vintage, I believe.

 

[JohnD]

I can't see any of the circuit cables, so I can't guess how old your house wiring is.

The incomer is around 70 years old, so very likely the original wiring was replaced at some time. Some of the surrounds look brown, suggesting either great age, or smoke staining from cigarettes or an open fire, and these may have older wires inside

the ones that are not working may not be the ones where the fault exists.

I think most likely there is a loose connection in one of the ceiling roses in the room where you recently carried out maintenance, and it was disturbed when handled. With lighting circuits it is especially important that each wire goes into the correct terminal, and you should mark them with tippex or a marker pen and photograph before touching. Colour is not sufficient identification.

If you find any rubber-insulated wires, or cracked or scorched insulation, you should call in a qualified electrician, as it is likely to be degraded with age and may crumble if touched. If it is glossy PVC it is likely to be fine.

 

[Mander]

I'm reasonably confident the wiring isn't too dodgy after having all that work done a few years ago. Eventually it needs rewiring, I know.

However I got up my courage to take the roses off and wiggled some wires and tightened some screws. None of them seemed especially loose but that did the trick. All working now!

These are the two I took apart. Someday soon I will get the kitchen redone and replace these with better lights.

 

[JohnD]

I can see the cables are PVC sheathed and insulated, which is satisfactory and lasts for many years. Red and black is an older standard, now replaced by brown and blue but this does not make the older cable unsafe.

 

[Mander]

Yeah it's a former council house that was built around 1950 and most likely had a full rewire in the 80s when the council did an improvement programme in the area. I think later owners had some not-so-great work done (some of the wiring in the kitchen is not chased in, for example) but all the problems flagged in the EICR were fixed.