Advice ref blinking lights all circuits

[Lukeowl]

Hi there,


I should start by saying I am not an electrician, but am after some advice as we have a problem that we aren’t getting any answers on.

In January, we had a new fuse board installed to replace an old edition one. This is a recent Wylex model with circuit breakers. The electricians who installed it also added some outdoor lights, a couple of sockets in the kitchen and updated a few sockets around the house for us.

Approx 10 days after the work completed we began to notice intermittent blinking on lights across both upstairs and downstairs lights and on lamps plugged into sockets. There is no rhyme nor reason to the blink – it doesn’t matter if any appliances are running or none, so we’ve ruled out a surge due to boiler, fridge, etc.

We spoke with the electrician who did the work, they inspected the connections at the board and said everything looked fine and they suggested it was likely to be a supply issue. Powergrid came out, inspected and setup voltage recording device and left that running for about 8 days. They say that there is no fluctuations from their side that would cause “flicker” so have said it’s not an issue from their end.

I’ve spoken with the electricians who did the install again, but they seem void of any idea on what to look for or what could be causing this problem.

Does anyone on this forum have experience of similar issues being related to anything non-supply related – so from the board onward internally? Is it possible a fault could be present on the board itself?

From searching google, there’s lots of suggestions that flicker on all circuits including sockets is likely to be a supply issue, but this isn’t really what I’d call a flicker. It’s a very short blink. More noticeable on filament bulbs than the LED types. Not ever so frequent enough to cause headaches or anything, but frustrating, annoying and worrying as I have 2 young kids and I am really paranoid about electrical safety (which is kind of the reason we had the old fuseboard replaced in the first place!).

Thanks in advance for any advice or ideas offered.

 

[MDJ]

It could be the main switch is not connected to the busbar properly and when there is load on the board it is making the circuits flash, get the sparks back to treble check all connections. If they refuse to do so, get a spark in to sort it, get his report and send the company the invoice.

 

[telectrix]

a favourite is the busbar incorrectly fitted to 1 or more MCBs. if you are competent to do this safely, with the board turned OFF at main switch , pull off the busbar cover and use a mirror if necessary to see if the busbar is behind the cage clamp. Remember to replace busbar cover before swiychting back on. DO NOT ATTEMPT UNLESS COMPETENT TO DO SO.

 

[Pete999]

Hi there,


I should start by saying I am not an electrician, but am after some advice as we have a problem that we aren’t getting any answers on.

In January, we had a new fuse board installed to replace an old edition one. This is a recent Wylex model with circuit breakers. The electricians who installed it also added some outdoor lights, a couple of sockets in the kitchen and updated a few sockets around the house for us.

Approx 10 days after the work completed we began to notice intermittent blinking on lights across both upstairs and downstairs lights and on lamps plugged into sockets. There is no rhyme nor reason to the blink – it doesn’t matter if any appliances are running or none, so we’ve ruled out a surge due to boiler, fridge, etc.

We spoke with the electrician who did the work, they inspected the connections at the board and said everything looked fine and they suggested it was likely to be a supply issue. Powergrid came out, inspected and setup voltage recording device and left that running for about 8 days. They say that there is no fluctuations from their side that would cause “flicker” so have said it’s not an issue from their end.

I’ve spoken with the electricians who did the install again, but they seem void of any idea on what to look for or what could be causing this problem.

Does anyone on this forum have experience of similar issues being related to anything non-supply related – so from the board onward internally? Is it possible a fault could be present on the board itself?

From searching google, there’s lots of suggestions that flicker on all circuits including sockets is likely to be a supply issue, but this isn’t really what I’d call a flicker. It’s a very short blink. More noticeable on filament bulbs than the LED types. Not ever so frequent enough to cause headaches or anything, but frustrating, annoying and worrying as I have 2 young kids and I am really paranoid about electrical safety (which is kind of the reason we had the old fuseboard replaced in the first place!).

Thanks in advance for any advice or ideas offered.

Sorry to hear about your problems Luke, did you have these flickering problems before you had your CU changed? When you called the Electricians back due to the problem, you say they looked at the connections in the CU and all looked OK, but did they actually check the soundness. tightness of all the connections? it's all very well them saying it looks OK but that's not the answer, checking the integrety of the connections would be the best option,
does the flicker occur randomly, is there any vibrations that may cause a loose connection to make and break, you say you have a couple kids, and we all know what they are like slamming doors etc.
Maybe one of the Forum Members close to your location, could offer to come and take a look, you're a bit to far away for me to offer, hope you get it sorted.
One more thing did the Electricians leave any certificates/paperwork with you when they left? you should have been in receipt of an Electrical Installation Certificate (EIR) on completion of the works.

 

[FatAlan]

Would really p*** me off if there were no issues before work was done and after so called ‘professional’ had conducted work that resulted in an issue, that ‘professional’ showed little interest in getting it fixed. You sure they were competent to do the work in the first place?

 

[Lukeowl]

Hi, thanks for the reply.

Yes, they checked the tightness of everything and I stood over them while they did it. In fairness, they've been very good, but seem stumped as to what the issue can be.

Yes, we have received the EIR paperwork and certificates.

This wasn't happening prior to the work being carried out, which is why I am making that link.

I also know for a fact that we didn't notice it in the immediate few days after the installation either - it was approx 9-10 days after that we begun to notice it.

The flicker is random - no vibrations - happens in all rooms at all different times of the day, even when kids are asleep.

It is really weird - there is no logical starting point to look for a fault as it is displaying on the upstairs lighting circuit, the downstairs lighting and also across table lamps plugged into sockets both upstairs and downstairs.

The one other thing that they did change was a previous shared neutral on the landing - they made use of a redundant cable that used to run to an old whirlpool bath pump that is was no longer in use to provide a neutral to the upstairs hall light. I have wondered if that could be a root cause, but then not sure why that would affect the sockets as well.

 

[shaun1]

If you have any high load apliences sutch as a shower or oven, or an electric heater, try switching these on and off and see if it affects the lights. A very slight dimming is normal but if its quite significant that could indicate a poor connection.

If you can get the electricians back, try and persuade them to remove and reterminate all the connections, including re fitting the busbars and neutral links to RCDs etc, and check both sides of the main switch. Any poor connections may become obvoius then, as if they have been arcing there will be some carbon buildup at the connections.

It could also be the connection of the meter tails into the meter that have worked loose if they were disturbed when the new board was fitted.

If you/they can get access to an IR camera this could help trace any high resistance connections whilst everything is switched on.

 

[Pete999]

Hi, thanks for the reply.

Yes, they checked the tightness of everything and I stood over them while they did it. In fairness, they've been very good, but seem stumped as to what the issue can be.

Yes, we have received the EIR paperwork and certificates.

This wasn't happening prior to the work being carried out, which is why I am making that link.

I also know for a fact that we didn't notice it in the immediate few days after the installation either - it was approx 9-10 days after that we begun to notice it.

The flicker is random - no vibrations - happens in all rooms at all different times of the day, even when kids are asleep.

It is really weird - there is no logical starting point to look for a fault as it is displaying on the upstairs lighting circuit, the downstairs lighting and also across table lamps plugged into sockets both upstairs and downstairs.

The one other thing that they did change was a previous shared neutral on the landing - they made use of a redundant cable that used to run to an old whirlpool bath pump that is was no longer in use to provide a neutral to the upstairs hall light. I have wondered if that could be a root cause, but then not sure why that would affect the sockets as well.

Bit naughty that last bit Luke, sounds like they had some RCD tripping problems and took the roughest route out of the problem, not something I would do, neither I suspect would anyone else, could be wrong of course.

 

[Lukeowl]

Thanks for all the replies everyone - really appreciate it.

I've just called to arrange a return visit from the electricians for a couple of weeks time - they are going to check all the connections and busbars again and also investigate the neutral that they took that existing cable for - they have even suggested putting that back as it was to see if it stops the issue. Not sure if that would be the cause though as it's happening on the sockets too.

@shaun1 - There doesn't seem to be any impact to the lighting when we put the oven on. The shower is a thermostatic valve mains pressured so that wouldn't give an indication. We have an electric fire that we don't really make much use of - I will try that this evening to see if that has any impact.

 

[Lukeowl]

Bit naughty that last bit Luke, sounds like they had some RCD tripping problems and took the roughest route out of the problem, not something I would do, neither I suspect would anyone else, could be wrong of course.

Indeed they had RCD tripping issues. They returned the following day with the intention of running a new cable from the board under the stairs up to the attic space above the light in the hallway. When they were seeking the easiest route to run the cable, they found the old cable that had been disconnected from the old bath pump and suggested using that as it was already there and would be less disruptive. I agreed because it made sense. Like I said above though, I am not sure if that would cause all the circuits to display these blinks?

Another point to add - we aren't experiencing any other issues with anything plugged into the sockets - TV's, chargers, radio, kettle, large appliances, etc - all running as normal.

 

[Pete999]

Indeed they had RCD tripping issues. They returned the following day with the intention of running a new cable from the board under the stairs up to the attic space above the light in the hallway. When they were seeking the easiest route to run the cable, they found the old cable that had been disconnected from the old bath pump and suggested using that as it was already there and would be less disruptive. I agreed because it made sense. Like I said above though, I am not sure if that would cause all the circuits to display these blinks?

Another point to add - we aren't experiencing any other issues with anything plugged into the sockets - TV's, chargers, radio, kettle, large appliances, etc - all running as normal.

Thanks for the update

 

[PEG]

Indeed they had RCD tripping issues. They returned the following day with the intention of running a new cable from the board under the stairs up to the attic space above the light in the hallway. When they were seeking the easiest route to run the cable, they found the old cable that had been disconnected from the old bath pump and suggested using that as it was already there and would be less disruptive. I agreed because it made sense. Like I said above though, I am not sure if that would cause all the circuits to display these blinks?

Another point to add - we aren't experiencing any other issues with anything plugged into the sockets - TV's, chargers, radio, kettle, large appliances, etc - all running as normal.

Hi,this would cause me to wonder,if they did adequate testing,prior to the fitting of the new DB,and,afterwards.

A few days later,is not the time this issue should have come to light.

Are the lighting circuits fed from one or two MCB's?
Where did the feeds originate from,for the outside lights?
Have the MCB's been removed and inspected,or just tightened?

 

[Pete999]

Hi,this would cause me to wonder,if they did adequate testing,prior to the fitting of the new DB,and,afterwards.

A few days later,is not the time this issue should have come to light.
Reckon you are spot on there PEG they must have had a tripping RCD problem, typical borrowed N on the two lighting circuits= no initial testing, connect up, conduct bang test etc.
Are the lighting circuits fed from one or two MCB's?
Where did the feeds originate from,for the outside lights?
Have the MCB's been removed and inspected,or just tightened?

 

[Lukeowl]

Hi,this would cause me to wonder,if they did adequate testing,prior to the fitting of the new DB,and,afterwards.

A few days later,is not the time this issue should have come to light.

Are the lighting circuits fed from one or two MCB's?
Where did the feeds originate from,for the outside lights?
Have the MCB's been removed and inspected,or just tightened?

Hi, thanks for the reply.

They are fed from 2 MCBs. One for upstairs and one for downstairs. As I understood it (I was at work while the work took place, my wife was home), when they connected it all up the lights kept tripping upstairs - so the options we were given were to leave the borrowed neutral as it was and only have them on a single MCB or to connect a new neutral to the board and the light - which is how we got to the scenario mentioned above where they utilised the existing disconnected cable.

The feeds from the outside lights - no idea on that. They are on a separate switch on the board (not sure if that indicates where they originate?) excuse my ignorance on this - I'm not electrically minded

The MCB's have not been removed and inspected - it was just a tightening that was performed.

 

[Octopus]

Just tightening isn't good enough ...

Make sure they check that the mcb's are clamped properly and the buzz bar is held securely ..

 

[gnuuser]

using an old cable is a bit risky especially if it went to a pool /hot tub?
unless they did an I.R. test on it to prove it was serviceable,
it may have had a little moisture in it. but as others have suggested this sounds like a loose connection somewhere.
also loose neutrals or intermittent neutral faults can cause electronics to mysteriously fail.

 

[Lukeowl]

Thanks for all the responses so far.

One question I have is around the safety of using the electrics while this is going on. The electricians have said they cannot come back to do a proper inspection until after Easter, and I've booked them in for the Thursday of that week - so, 3 weeks tomorrow.

Are we safe to continue using the lights and sockets as we have been doing? If the fault is caused by a loose connection in the panel somewhere - should the breakers work to cut the supply if the fault developed into something more significant?

Thanks!

 

[Pete999]

Thanks for all the responses so far.

One question I have is around the safety of using the electrics while this is going on. The electricians have said they cannot come back to do a proper inspection until after Easter, and I've booked them in for the Thursday of that week - so, 3 weeks tomorrow.

Are we safe to continue using the lights and sockets as we have been doing? If the fault is caused by a loose connection in the panel somewhere - should the breakers work to cut the supply if the fault developed into something more significant?

Thanks!

Can't come back for 3 weeks, to what could be a dangerous installation? am I smelling a rat or just being a misery, speak to them again and insist that the response is sooner rather than later and if they still play hardball get someone else in and charge the original Electrician, could be rather tricky, but safer in my book, 3 weeks my derriere.

 

[Lukeowl]

Can't come back for 3 weeks, to what could be a dangerous installation? am I smelling a rat or just being a misery, speak to them again and insist that the response is sooner rather than later and if they still play hardball get someone else in and charge the original Electrician, could be rather tricky, but safer in my book, 3 weeks my derriere.

I've spoken with them again and managed to get them to agree to return next Thursday. I don't want to speak ill of them - they have done work for us previously at a property we lived at before and that went well - in fact a similar job to this one with a fuse board swap out. We were also pleased with the work they did for us on this job as well - it's only since this blinking started that I'm left scratching my head looking for answers.

I don't understand how the shared neutral swap out for the hallway and landing lights could cause a knock on effect to the rest of the circuits and lamps on the sockets though.

I am a completely ignorant with how electrics work, but from what I've seen online and from speaking with people, the suggestion appears to be the issue is either in the box or via supply - this based on the fact that the lamps are also producing the same blink.

One other thing - it's not really noticeable on LED candle bulbs, but is on spot lights (LED and halogen) and oldschool fillament / energy bulbs. Any idea why this would be?

Does anyone actually have previous experience of similar symptoms that were resolved via a particular course of action? It seems very much shooting in the dark to locate the source of the problem.

 

[Pete999]

I've spoken with them again and managed to get them to agree to return next Thursday. I don't want to speak ill of them - they have done work for us previously at a property we lived at before and that went well - in fact a similar job to this one with a fuse board swap out. We were also pleased with the work they did for us on this job as well - it's only since this blinking started that I'm left scratching my head looking for answers.

I don't understand how the shared neutral swap out for the hallway and landing lights could cause a knock on effect to the rest of the circuits and lamps on the sockets though.

I am a completely ignorant with how electrics work, but from what I've seen online and from speaking with people, the suggestion appears to be the issue is either in the box or via supply - this based on the fact that the lamps are also producing the same blink.

One other thing - it's not really noticeable on LED candle bulbs, but is on spot lights (LED and halogen) and oldschool fillament / energy bulbs. Any idea why this would be?

Does anyone actually have previous experience of similar symptoms that were resolved via a particular course of action? It seems very much shooting in the dark to locate the source of the problem.

Personalyi think the shared N maybe a red herring, it may not be the reason for the blinkung light issue, my problem withe the issue is, they should have checked this issue prior to the CU fitout, it's not an ideal method to use a cable that has been redundant to solve a problem that should have been sorted earlier, I would go as far as saying it's a rough solution, but without seeing the install it's maybe jumping the gun.

 

[ipf]

, it's not an ideal method to use a cable that has been redundant to solve a problem that should have been sorted earlier, I would go as far as saying it's a rough solution, but without seeing the install it's maybe jumping the gun.

I don't necessarily agree there, Pete. If they've tested the cable and it's in decent nick, it could well have saved a lot of trouble both for them and Luke. It's not a full rewire, after all. Maybe they should have taken into account the shared neutral, but they obviously got to the bottom of that problem, quite easily. As you say, it's easy to assume without seeing. They seem a decent crew.

 

[FatAlan]

I’m far from being an expert but logically if you’ve had the CU replaced on a system that was ok before and have a flicker on two seperate circuits it suggests the fault is upstream from the MCB’s. As others have suggested ... loose connections to mainswitch, tails etc. Presumably there’s some RCDs in there as well?

 

[Octopus]

^^ good input .............. seem loose connections on the DNO head do this ..............

 

[Rpa07]

I would normally say that it may be a supply fault on one of the phases. Same thing happened in my house with blinking lights.
I didn’t ask around the neighbours to see if the same was happening next door or 2 down or 3 down to correspond with the phase (although the OP could do this if not done already)
The supplier corrected a fault on the supply and has been good since.
The OP had the DNO out to data log so that would and should have picked up something supply side.
I’m with everyone else otherwise and root for something loose that needs a wiggle to check.
Hope you get sorted.

 

[DPG]

I'm going to stick my neck out and say an intermittent neutral joint in the cable under the pavement, where the house is tapped off the main feed.
I want a prize if I'm right though.

 

[shaun1]

One other thing - it's not really noticeable on LED candle bulbs, but is on spot lights (LED and halogen) and oldschool fillament / energy bulbs. Any idea why this would be?

Tungsten filament bulbs are very basic - the filament is connected between live and neutral and the light output is (kind-of) proportional to the voltage across it. So when there is a dip you will see a drop in brightness.

LED bulbs and most electronics are powered via electronic outputs, which can adjust themselves so they always give the same output for a wide range of input voltages right down to 100v (we are at 230v (which is usually 240) here in the uk). They also have capacitors which act like a battery to store current and smooth the output during voltage fluctuations.

With regards to safety, loose connections and high resistance connections create localised heating, which can then make the problem worse, and can eventually become a fire risk. Circuit breakers and RCDs may not operate in this situation as there is no overcurrent or imbalance.

There has just been an amendment to the regulations stipulating that consumer units in houses now have to be made from a non combustible material to contain faults such as this and to prevent fires.

Whilst I don't think you need to immediately panic if there's no obvious cause, I don't think waiting weeks is acceptable. If the flickering gets worse or more often, or you notice a burning or fishy smell (melting insulation) around the CU then it may be time to turn of and demand they come back immediately.

 

[PEG]

Back in the good old days,before LED's and low energy gubbins,a chandelier of 500w halogens,would have already pushed this fault,to an obvious head

 

[Deleted member 26818]

Had something similar once.
Turned out to be an ill fitting main fuse holder.
The sprung legs were corroded and had lost tension over the years. Also the screw terminals for all conductors at the head were loose.

 

[Pete E]

If the flicker affects table lamps plugged into socket outlets, maybe next time the fault occurs, switch off the lighting ccts via their MCB's and see if the flicker on the table lamp stops?

 

[telectrix]

when all else fails, call in:

 

[Squid]

when all else fails, call in:

May The Power of Laugh Be With You,

Where did you dig that one up from?

 

[Wilko]

Apologies if you've already given this detail - how often is the dimming, how deep and duration?
I love a fault - much more interesting than TV

 

[Lukeowl]

Apologies if you've already given this detail - how often is the dimming, how deep and duration?
I love a fault - much more interesting than TV

Hi there.

It’s hard to answer with specifics. I’ve noticed it pretty much daily - at different times of day and no real set interval between.

The dimming itself is almost like a blink. It’s not what I’d call a flicker - it’s more a flash. Imagine looking at a light and blinking while doing so - it’s very quick.

I can’t really think how else to describe it.

Sometimes I’ve noticed it two or three times in a 10/20 minute period, other times I’ve not noticed it at all in the same time span.

It’s frequent and obvious enough to be a concern to me though.

 

[Kjr79]

Main tail are in reverse live and neutral, probably mixed at the meter when they changed the tails

 

[littlespark]

These questions have maybe been answered before.
Do the lights flicker in unison across all the circuits? Have you tried a table lamp in an alternative socket ie, cooker unit? Still flickers?
If it does, it must be something common to all circuits, such as the supply. If this only started happening after the CU change, then very possibly a loose connection on something that has recently been worked on.
Have ALL connections been retightened? even the factory fitted? (Neutral link between mainswitch and neutral bar?)
It is very easy to misalign the busbar when fitting MCB's. It can sometimes slip up behind the clamp of the breaker, and tightening up the connector screw makes no difference.
Working on the CU tails may have loosened them at the meter just by moving them around. Not something your electrician can check if the seals are still in place.
How does the supply cable come into the house? Overhead wires can give problems, but of course that's up to the Network to check.

We would all be interested to find what the problem is once its been identified.

 

[shaun1]

Main tail are in reverse live and neutral, probably mixed at the meter when they changed the tails

Why would this cause a flicker?

 

[Kjr79]

Reverse polarity!! Energy savers

 

[littlespark]

Reverse polarity!! Energy savers

Politely disagree.
I don't think it would be reverse polarity. The OP said it was ceiling lights as well as table lamps. Likely to be bayonet cap fittings - doesn't matter which way round they're put in... and also said it happens with filament lamps... not 'energy savers' in the sense that if they are CFL or LED.
And between the electrician, his return visit and the ones that came to check the supply, someone would have visually noticed the cables being reversed between the meter and the CU.

 

[Kjr79]

L NN L

Let’s hope your right pretty scary that these electricians haven’t been able to resolve it ‍

 

[Lukeowl]

Politely disagree.
I don't think it would be reverse polarity. The OP said it was ceiling lights as well as table lamps. Likely to be bayonet cap fittings - doesn't matter which way round they're put in... and also said it happens with filament lamps... not 'energy savers' in the sense that if they are CFL or LED.
And between the electrician, his return visit and the ones that came to check the supply, someone would have visually noticed the cables being reversed between the meter and the CU.

I should say that it has been noticeable on LED GU10 bulbs, and also on the old energy saver types (not LED - the ones that looked like small tubes in a loop). It was just more noticeable on the filament type bayonet bulbs. I’ve replaced all them filament types with LED bayonets now and it’s no longer noticeable on those lights, but is still happening on the GU10 bulbs in the kitchen, bathroom and bedroom.