Wylex Consumer Unit replacement help.

[Benny5]

I’m looking at getting estimates to have my Consumer Unit (6 way Wylex unit in a 1960’s house) replaced. The addition of circuits over time has resulted in the box being very crowded.

The query I have is that with my lighting circuits being the original (without any earth) and some of the plug circuits also original am I likely to have issues with RCD’s tripping. The kitchen and bathroom were rewired fairly recently so shouldn’t cause any issues.

Without going down the route of a re-wire is there a way of establishing the quality of the installation before any work starts. Is it possible to get the contractor to run some type of meter test across the circuit at the CU?

 

[flameport]

is there a way of establishing the quality of the installation before any work starts

Yes, and that is an essential part of having a new consumer unit installed.
All of the circuits must be fully tested and inspected, and any repairs required done before the new consumer unit is installed.
Some testing is also required after the new consumer unit is installed.

The actual installation of the consumer unit is a relatively small part of the work required.

 

[Benny5]

Yes, and that is an essential part of having a new consumer unit installed.
All of the circuits must be fully tested and inspected, and any repairs required done before the new consumer unit is installed.
Some testing is also required after the new consumer unit is installed.

The actual installation of the consumer unit is a relatively small part of the work required.

Thanks for that.

I’m just debating whether to leave things as they are as any re-work/re-wire would disturb a lot of decorating.

Before going any further do you have any idea of the cost of the work you describe above, it’s a three bedroom Simi?

 

[Taylortwocities]

If you leave things as they are then you are on a hiding to nothing.
Have a qualified electrician carry out a report (EICR) on the installation. That will tell you what should/must be sorted out. Have that done and then get your CU changed.
You have already identified no earth on lighting circuits. You’ll be stuck with only plastic / double insulated lights and switches unless you get that updated.

Costwise, for change of CU? Allow about the same as a weekend away. Does that help?

 

[AndyPRK]

Find an electrican which will do an ECIR before starting work. And on a different day. Not all like to do this, so you may need to shop around.

Do get caught out on a cheap ecir like this.

 

[Benny5]

If you leave things as they are then you are on a hiding to nothing.
Have a qualified electrician carry out a report (EICR) on the installation. That will tell you what should/must be sorted out. Have that done and then get your CU changed.
You have already identified no earth on lighting circuits. You’ll be stuck with only plastic / double insulated lights and switches unless you get that updated.

Costwise, for change of CU? Allow about the same as a weekend away. Does that help?

Find an electrican which will do an ECIR before starting work. And on a different day. Not all like to do this, so you may need to shop around.

Thank you both for the prompt responses.

I’ll wait for the current crises to abate and then follow it up.

Cheers, Benny.

 

[ajohn]

I wouldn't have an eicr done and I also want a wylex unit replacing, we have 2. I order to quote an electrician must know what work does need doing so they need to take a look and do some testing. Use this aspect as one of your electrician selection criteria or at least ask about this aspect. Some electricians will take a look around before quoting. If they didn't a couple of hundred quid on labour could easily turn into several times that and lots of house disruption.

EICR's are a mixed bag. Looking at ever aspect of wiring often isn't possible and things found that depart from current standards are noted and graded - that doesn't mean that they must be changed and this can get confusing and one electrician might even grade differently to another.

You know you have one problem and some one mentioned a fix. The question does remain that would all electricians view it the same way. You may have others. For instance I know I have a lot of unsleeved earth leads behind switches and sockets. Something I will very probably fix myself. I've no idea how an electrician would grade that. Lack of it has never ever caused any problems. I also know that the electrics are all functional. Having seen a lot of the wiring I know I have no overloaded cables that have leached plasticiser - that happening may also be down to previous use of crap cable.

The other aspect is making sure that the electrician is on the competent person register - the one that covers all of them and also make sure they leave the correct paperwork behind. The paperwork does extend the time on the job and some might not like doing it even if they do test correctly.

 

[Benny5]

I wouldn't have an eicr done and I also want a wylex unit replacing, we have 2. I order to quote an electrician must know what work does need doing so they need to take a look and do some testing. Use this aspect as one of your electrician selection criteria or at least ask about this aspect. Some electricians will take a look around before quoting. If they didn't a couple of hundred quid on labour could easily turn into several times that and lots of house disruption.

EICR's are a mixed bag. Looking at ever aspect of wiring often isn't possible and things found that depart from current standards are noted and graded - that doesn't mean that they must be changed and this can get confusing and one electrician might even grade differently to another.

You know you have one problem and some one mentioned a fix. The question does remain that would all electricians view it the same way. You may have others. For instance I know I have a lot of unsleeved earth leads behind switches and sockets. Something I will very probably fix myself. I've no idea how an electrician would grade that. Lack of it has never ever caused any problems. I also know that the electrics are all functional. Having seen a lot of the wiring I know I have no overloaded cables that have leached plasticiser - that happening may also be down to previous use of crap cable.

The other aspect is making sure that the electrician is on the competent person register - the one that covers all of them and also make sure they leave the correct paperwork behind. The paperwork does extend the time on the job and some might not like doing it even if they do test correctly.

Thanks for your input.

Like your situation, I realise my system may have some shortcoming by today’s standards, however, everything functions and I have never suffered fuses/MCB’s failing.

Sadly I find myself in that age group where the Health Minister has just suggested I ‘self isolate’ for possibly 4 months. Therefore,replacing my CU will have to take a back seat for now.

 

[ericmark]

I am nearly that age, a year to go, my son replaced mine, and he did not do a full test, he knows I am an electrician as well, so expected me to sort out any faults, and there was one, the lights in hall and landing had the neutrals swapped, for me not a problem, however for a non electrician that could be a major problem.

You would not believe how many times one finds for years a house has had a borrowed neutral, in some cases from original build, others after some one has split upper and lower lighting. The easy cheap (time wise) cure is the MK kinetic switch, we are talking about £70 to fit, as to where there is an existing fault the electrician pays to correct or house owner is up for debate.

However £70 is less than a EICR so maybe worth taking a chance? However if no EICR is done, it may mean a £400 bill instead of £500 bill, but if it does not work out, the £400 bill could go to £600, so it depends if you can absorb the costs if some thing goes wrong.

 

[Taylortwocities]

There is no point changing a CU if there are faults with the wiring. At the end of the installation, the electrician has to fully test every circuit anyway, complete the test schedule and confirm that they comply with the relevant standards. Its better to make these tests on the circuits before the old fuseboard is removed as there's no going back once the new RCD/RCBO board is in place. With some faults you then can have an installation with no power.

Test installation first
Resolve wiring issues
Change CU

 

[EFLImpudence]

I have always had trouble with this idea that an EICR should/must be carried out before a CU is changed.

Obviously it depends what you mean by 'before' - you would hardly do it afterwards.

The tails can be clamped to determine the overall situation and if an RCD is likely to trip.

So, is it meant that the circuits are tested - one at a time - when they are disconnected from the old CU? If so, then I would ask "How else could it be done"?

I do not consider that 'before' but 'during'.

Then if one circuit, for some reason, would not work with the new CU, do you refuse to fit it or somehow compensate for the incompatibility on a single circuit?

 

[ajohn]

Really checking all of the electrics completely is a no no. For instance all wiring here is is from the first floor as the ground floor is solid. A full look around would need a lot of floorboards lifting.The only feasible thing is cable testing.

A borrowed neutral is an interesting one - I'll be scratching my head about how to test for one before any changes. A quick fix on lights after a cu change might be to run both light circuits off one rather than 2 rcbo's but say the socket circuit had been used. Or go around switching various numbers of lights off until the culprit is found.

My comments on selecting an electrician came from talking to one who did a small job for us so asked about CU upgrade. He said around £250 including testing. He assumed no more ways than we currently had. He didn't say somewhat depends on what he finds or for that matter what I want fitting. For various reason I want all rcbo's. He'd be just assuming the cheapest CU he could find. I also want more circuits and in my view some spares should always be left. I might start driving a hybrid for instance - probably would if any of them gave an idea of range on battery. I'll also need a new garage feed - interesting one as ideally I want it's rcbo's to be independent of the main CU. He might get the job as I liked how he worked but I want more discussion than was offered.

 

[flameport]

He said around £250 including testing.

Impossible for anyone to supply and properly install a replacement consumer unit for so little.

 

[Benny5]

Thanks for all the various inputs.

My original question was prompted by my desire to firstly establish the integrity of the circuits and should they be ‘issue free’ then proceed with the change out. The last thing I want, is having replaced the CU, to then find failings that necessitate ripping up floor boards, disturbing light fittings, switches and plugs. I know this may not be the best attitude but I’d prefer to leave things as they are rather than all the hassle of extensive fault finding.

Incidentally, I was legislating for a spend of £400/£500. I already have the replacement CU (Honeywell MK K7666). Homebase were selling them off recently for £22.

 

[flameport]

Homebase were selling them off recently for £22.

That's because they contain the wrong type of RCDs and don't have any provision for surge protection, and rather than keep up to date with regulations, MK have decided to exit the market completely and dispose of their obsolete stock. It's all gone now, including spare MCBs/RCBOs.