Any electricians here could "diagnose" my leccy problem?


Well-known Member
I got my consumer unit replaced before Christmas, from the old "pull-fuse" type to the more modern "trip" type. Since then we've had nothing but problems. What happens is, the big house ring trip switch seems to have a life of it's own. Sometimes it trips when I turn the garage (fluorescent) light off. Sometimes it's the oven dial on the cooker that trips it. Sometimes it's the cooker switch at the wall. Sometimes the vacuum cleaner does it. Sometimes the electric whisk. And sometimes it does it all on it's own (twice today!). Sometimes it would go for weeks on end not tripping at all. And it's driving us round the bend. We've had an electrician out and he says it may be a neutral to earth somewhere in the house and it's only started showing up since we changed the unit. But then again, he says, that would only happen when you turned things on, not off.

So if there are any electricians here that may be able to help, please do.


Sounds similar to a problem we had with a bathroom light in a previous house , that was an earth fault , but as you say only happened when turning on.
Can't you get the sparks back that fitted it ? I'm sure you have to have some sort of continuity test done with a new consumer unit . We had to have one done (test) in the bathroom and all we had done in there was new lights and a shaver socket . And you should have some sort of guarantee with it , in case the CB is faulty . I think a new CU is notifiable work these days as well
Not much help , sorry



Distinguished Member
newer consumer units...especially the split ones are really sensitive and are easily tripped so it might be an old problem that your previous box did'nt pick up so to ring circuits and sockets as you probably know are seperate and should'nt normally would'nt interfere with each other....
could be a slow process on the fault finding front but someone would have to try and trace the fault on each circuit.....sounds like the sparky you had round probably did'nt want the hassle of doing the job.
you could have all the face plates off the sockets and light switches one by one just to check its not anything really obvious.....
affraid you'll have to try another electrician,explain on the phone and try and sort something out before he calls round...
not much help i know but i think the fault could be anywhere....i had a problem once which was finally traced to a socket behind the cooker (fogot there was even one there),the metal casing was nipping a wire slightly.
someone else might be able to shed more light.


Well-known Member
A CU change should be carried out by a competent person belonging to one of the governing bodies, for EG NICEIC, ECA, Napit etc.

You should have been issued an Electrical Installation Certificate after the work was complete, along with a schedule of test results which should have been carried out before the CU was changed.

Any faults should have been picked up through the tests and any remedial works carried out, at extra cost to you.

If none of the above have been carried out then i suggest you contact the original contractor and ask the questions.

The certificate should have the logo of which ever body he belongs to.

If it does and he refuses to co-operate then i suggest you contact the NICEIC or whoever he is with and lodge a compaint.

They may or may not sort this for you but of not, then i suggest you contact a known competent spark who would carry out the remedials, but you may find it could cost you a fair bit.

Sorry to be the bearer of bad news, but this is happening all too often nowadays.


Active Member
When I had my kitchen extended the electrician warned me that due to 'Part P' (whatever the bl***y hell that is) - any work they do will now involve the rest of the wiring in the whole house.....He insisted on replacing the CU and various other bits of wiring.

Lucky for me it all worked and no probs but to be fair the point of all this is to try and keep people safe. I've been an electronics engineer for thirty years and I'd like to think I know what I'm doing.

You never know what's lurking in a house unless you've owned it from new (mine's 125 years old) so unless you're an expert, be grateful it's shown up any possible dangers! Let's face it there are plenty of cowboys out there and you don't know how many of them have worked on your house over the years...


Well-known Member
When I had my kitchen extended the electrician warned me that due to 'Part P' (whatever the bl***y hell that is) - any work they do will now involve the rest of the wiring in the whole house.....He insisted on replacing the CU and various other bits of wiring.

That is not strictly true.

PART P is a new building regulation which means that most electrical work carried out in residential proerties has to be notified to building control. Self certifying sparks do not have to do this as they are supposedly 'competent'.

When an addition to a house is made and an electrical installation is added to, it DOES NOT include the rest of the wiring in the house.

Yes, the sparky involved must be sure that any addtions are not going to 'overload' the existing supply, but, if a new CU is to be fitted then a check should be made on the existing installation (earthing etc).


Active Member
defo neutral to earth fault, but where is another story, get the sparky back to try and find it, if he cant as its not always possible then the trip may have to be less sensitive as a means to fixing the problem, we have this alot but 99% of the time we find the fault,


Well-known Member
You don't strictly have to be a member of one of the governing bodies, just the majority tend to be.

Very true. Anyone can change a cu but it must be notified to the LBC before, submitting to them the appropriate fee and they would send someone to test.

But, as many LBC's are to go by, they dont want the hassle and may suggest you leave it or get someone else to test and cert.

However, most sparks, me included, wouldnt go near it and would certainly not sign it off. Unless they carried out a full PIR. This would then pick up the fault and would have to be sorted before any cert issued and would be charged accordingly.

Unfortunately, most governing bodies will not permit their members to sign off others work.

As to the fault, it could be a N-E problem, but in many cases it can be a faulty appliance eg fridge/freezer, that could be faulty or an abnormally high earth leakage current.

Just get a proper sparky to sort it. It will save an awful lot of hassle in the long run.

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