Its not so much the CU swap that can highlight latent problems, as the introduction of circuit level RCD protection for the first time. Generally still worth doing IMHO since that's one of the big gains in safety (to both people and property).
If you go for a "high integrity" CU (i.e. a modern 17th edition style unit with multiple RCDs, but also some non RCD ways. Then if you do encounter any problem circuits you can always temporarily put them on non RCD MCBs to get the power back on. Allowing more time for full diagnosis and fix later.
No, but you can pay for an EICR (inspection and test, was called a PIR)
You will not automatically fail just because it was wired to the 15th edition or whatever - but you will get some "needs improvement" items which you can interpret as you wish.
And the words being "can open" are important. More houses manage a fusebox to CU swap without major problems than do have major problems. Most houses built in the 80s had fuse boxes and their electrical installations are fine.
My dad was an MIEE (power engineer for the LEB). he was asked to comment on the regs back around the 14th edition froma general usability point of view.
"Too long" he said.
What he meant was that the typical user of the regs would have to plough though an awful lot of material - much of which was not relevant or necessarily that clear.
I agree with him there. All the extra "fluffy" rules do is:
1) Have sticklers like me in a panic trying to fathom if we've accounted for everything;
2) Add bulk and too much constant change so practitioners have a hard time keeping abreast;
Now a good deal of that was addressed by Whitfield and his pocket guide, and the OnSite guide.
But right now, you've got a single big book covering agricultural, industrial, hostpital and domestic domains. A large proportion of sparkies will not ever go to two of those domains (Commercial I lump in with domestic as being sufficiently similar).
So there's a case for breaking the book in to volumes - main core (domestic/commercial) with add on volumes for specialist sites.
And then there's this constant publishing of amendments - again, ridiculous waste of money for a few changes.
One edition, every 10 years max IMHO. If it was safe today, it is not suddenly a lethal hazard tomorrow just because an amendment says so (see plastic CUs discussion).
If there's an issue with plastic CUs, it is down to the BS (or EU) standards to address IMO, not the wiring regs. The regs should just assume a UK approved CU is fit for purpose, save for special locations (eg agri/industrial/petrolchem/mining).
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.