Worried about intermittent bathroom lights flickering

Alex1M6 said:

Hi everyone,

My parents have some 240v GU10 down lights installed in the bathroom which all independently suffer from intermittent flickering. They're all LED's but the same behavior can be observed when swapped out with halogens which leads me to believe there is probably a loose connection somewhere. Its not very noticeable in the day but once it gets dark it becomes very apparent.

There is just a pull switch which I've made sure all terminals are tight, and shower extractor fan+switch which doesn't affect the flickering as it still happens with the fan switched off.

Now the problem is we had a loft conversion a few years ago and in the process all of the upstairs wiring and terminals/junctions have been entombed under massive wooden flooring sheets leaving no way to access anything. The bathroom actually has a walk in cupboard built on top of it yet the lights are not even the enclosed fire rated type.

My parents are very reluctant to do anything about it because of the loft conversion above, but just because nothing bad has happened yet it doesn't mean that things can't deteriorate. I've already mentioned the fire risk from loose connections but they don't seem too bothered about it. mg_smile:

Should I be worried about this and if so what would appropriate course of action be? Other lights in the house don't flicker apart from the loft room which exhibits the occasional flicker (all four lights in sync this time) but not as prevalent as the bathroom lights. I think the lights upstairs all used to connect at some common junction box but I'm not sure if that's still true since the loft conversion.

Any advice would be appreciated,
Thanks.

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Fire rated is only necessary when there is a "separate" dwelling above it!

Unfortunately I think you need to access the JB's to make a proper assessment.....

Try linking out the pullswitch, it might just be poor switch contacts (unlikely but do the simple things before assuming the worst). Also try removing all lamps but one. A loose connection or poor contact will generally be more apparent with greater load,and less with reduced load........I assume you are not an electrician, don't put yourself at risk if you are not competent to safely isolate and confirm safe isolation.

Thankyou both for the responses.

Murdoch said:

Fire rated is only necessary when there is a "separate" dwelling above it!

Unfortunately I think you need to access the JB's to make a proper assessment.....

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The converted loft is now a bedroom so I guess that would count as a dwelling? The walk in cupboard off to the side of the loft (above the bathroom) is used for permanent storage so there are lots of items such as camping gear in the space above the bathroom.

wirepuller said:

Try linking out the pullswitch, it might just be poor switch contacts (unlikely but do the simple things before assuming the worst). Also try removing all lamps but one. A loose connection or poor contact will generally be more apparent with greater load,and less with reduced load........I assume you are not an electrician, don't put yourself at risk if you are not competent to safely isolate and confirm safe isolation.

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Back when we were swapping out the bathroom halogens with LED's I noted the flickering was more noticeable with a mix of both LED's and halogens, it seemed the higher current draw of the halogens made the LED flickering more apparent but the halogen itself wasn't as noticeable. I guess because incandescent types have a slight thermal inertia where it takes a split second for the filament to cool down and emit less light.

I'm pretty sure the LED's were only rated for 220-240v rather than 100-240v, which could explain the more logarithmic flickering if the feed momentarily hits dropout voltage of the LED's internal driver.

You are correct in that I am not a qualified electrician. I do understand how electricity works and how to be safe but also the importance of having someone qualified carry out work to regulation standards. I'll mention shorting out the switch contacts to a relative who is qualified to 16th edition regs (former electrician), but even they've said not much can be done since everything has been buried under floor sheets and built upon.

This is ultimately where my concerns come from and why I started this thread, what are the chances of fire if the upstairs lighting circuit is deemed inaccessible/too much work and left unchecked? This house is about 60 years old now and does show signs of movement.

Oh the joys of old houses :dead:

all independently suffer from intermittent flickering

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So they don't flicker in sync? If not, the problem is unlikely to be the switch or any common connections, and would likely be at the lampholders. In which case, I'd much more suspect the holder contacts than the wiring terminals. Have a look on the side of the pins of one of the lamps, for signs of arcing where the contact leaf is supposed to press. Or see if they can be provoked into flickering by tapping the luminaire.

Separate dwelling means it has a different front door, NOT just a bedroom door!

Some GU10 LED lamps suffer from overheating, which can cause them to shut down - sometimes momentarily, sometimes for seconds or longer. I noticed one at my local theatre a couple of nights ago, one lamp kept shutting down for half a second, then was OK for a minute or two, then shut down again. From your posts, it doesn't sound like this, but you might want to just check the lamps somewhere else, preferably in a similar housing that contains the heat per the bathroom housings, just in case it is a lamp issue.

Murdoch said:

Separate dwelling means it has a different front door, NOT just a bedroom door!

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I dont agree with you here, if you are cutting a significant hole in a fire barrier your fitting needs to be fire rated. Would you fit non fire rated downlight lights in a kitchen below a childs bedroom.?

bigspark17 said:

I dont agree with you here, if you are cutting a significant hole in a fire barrier your fitting needs to be fire rated. Would you fit non fire rated downlight lights in a kitchen below a childs bedroom.?

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Table A1 in appendix A of Approved document B gives times for provision of fire resistance. And it includes all penetrations through fire resisting materials not only if there is a habitable space above with its own front door.

Lucien Nunes said:

So they don't flicker in sync? If not, the problem is unlikely to be the switch or any common connections, and would likely be at the lampholders. In which case, I'd much more suspect the holder contacts than the wiring terminals. Have a look on the side of the pins of one of the lamps, for signs of arcing where the contact leaf is supposed to press. Or see if they can be provoked into flickering by tapping the luminaire.

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Could also be poor quality LED lamps, if they were £1 a pop jobs from china.

Lucien Nunes said:

So they don't flicker in sync? If not, the problem is unlikely to be the switch or any common connections, and would likely be at the lampholders. In which case, I'd much more suspect the holder contacts than the wiring terminals. Have a look on the side of the pins of one of the lamps, for signs of arcing where the contact leaf is supposed to press. Or see if they can be provoked into flickering by tapping the luminaire.

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The lamp and fixture contacts all look clean with no obvious signs of arcing, I tried tapping on the front of the fixture and surrounding ceiling but that didn't provoke them into flickering on demand. The only way I can get the lamps to do it is by turning them off and on again but once it settles they will go back to flickering at random (but at different paces/intensities).

With the bulb removed and a flashlight at the right angle I can see two cables (daisychained?) going into the terminals at the top of one of the fixtures, it looks like 3 core and earth has been used expect there's only a one way switch and the grey and earth wires are just hanging free. The outer insulation doesn't look like it extends all the way up to the cord grip either although its really difficult to see as access is practically non existent without removing a divider wall then ripping up carpet and flooring.

SJD said:

Some GU10 LED lamps suffer from overheating, which can cause them to shut down - sometimes momentarily, sometimes for seconds or longer. I noticed one at my local theatre a couple of nights ago, one lamp kept shutting down for half a second, then was OK for a minute or two, then shut down again. From your posts, it doesn't sound like this, but you might want to just check the lamps somewhere else, preferably in a similar housing that contains the heat per the bathroom housings, just in case it is a lamp issue.

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That's a good suggestion except it also happens with halogens installed too. The fixtures are completely open at the back and I could feel a cold draft coming from in between the ceiling and floorsheet which I suppose would help with cooling.

wirepuller said:

Could also be poor quality LED lamps, if they were £1 a pop jobs from china.

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They are Philips LED bulbs from a couple years ago but it does happen with halogens in those fixtures too. We've had cheap LED's elsewhere in the past but found them to be rubbish.

bigspark17 said:

I dont agree with you here, if you are cutting a significant hole in a fire barrier your fitting needs to be fire rated. Would you fit non fire rated downlight lights in a kitchen below a childs bedroom.?

Click to expand...

charlie76 said:

Table A1 in appendix A of Approved document B gives times for provision of fire resistance. And it includes all penetrations through fire resisting materials not only if there is a habitable space above with its own front door.

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This is what they look like from below, its hard to see in the photo but the flooring sheet for the loft room is about 25cm above the hole.



This is not looking too good :frown: