New Consumer Unit

Except there really is no need for the main 100mA RCD and it would serve no purpose apart from creating nuisance tripping.

If the supply had very long tails then perhaps I can perhaps understand the 100mA RCD closer to the supply but it should then be one with a time delay for discrimination.

It must always be a time delayed 100mA RCD if used with 30mA RCD further down the line.

It does not matter where you put the 100mA RCD - close to the CU or close to the CU - remember a RCD only checks for an imbalance of current.

That's the point of testing afterwards......

If nothing trips and there are no problems you have just charged £695 for £160 of parts (that you can claim the VAT back on) for three hours of labour to swap the CU and do a basic test.

Do a proper EICR for 4-5 hours before the CU swap and you should know all the faults beforehand and be able to tell the customer the real cost of the remedial works.

Apologies for coming back on this but I thought somebody had mentioned good quality manufacturers, including Hager, but I can't find the post now.

Any recommendations please?

I haven't installed one for 24 years but ISTR people talking about wylex and crabtree favourably

Screwfix sell both.

Hager are one of my favourites.

I have recommended them many times.

I have a Hager, it seems decent enough. I asked the electrician to fit them instead of a Fusebox, as I'm likely to be doing additions at some point and don't want to end up with a no-brand where you can't get the parts any more.

Wylex and Crabtree are both made by Electrium. They fine AFAIK, but I'm not sure there's any difference (ie I can't obviously see one as the 'Audi' and one as the 'Skoda' with one being obviously superior).

Avoid MK, who are just a brand slapped on Chinesium now.

Theo