New Consumer Unit

Possibly make provision for future additions such as a EV charging point and have extra spaces, and capacity, for future equipment you may need in old age to support continued living in your own home.

Isolation switch between the DNO (Distribution Network Operator)incoming fuse and the consumer unit.

All sounds reasonable for what you'd expect to be fitted now.

But would have thought they'd do an EICR beforehand so that they know the state of ring continuity, insulation resistance, supply earth impedance, missing earth on old lighting circuits, borrowed neutrals, etc otherwise they could end up finding issues after the new board is fitted ...

As they've quoted a price, I expect that's based on their favoured brand.

Well if using decent quality parts and assuming he means all circuits are RCBO protected, then £250 of that is materials... (based on a quick pricing assuming 8 circuits in a 10 way Hager CU)

So all RCBO is good - better discrimination under fault conditions, and less risk of nuisance RCD trips.

I expect he has factored in some time to allow for fixing existent faults that may not be apparent at the moment (like borrowed neutrals etc).

Might be worth enquiring what he would use...

Aside from not being shiny and new, what is wrong with the current setup?

Good question! If a fuse goes in the current unit it is a PITA to replace involving poking the fuse upwards then lifting it out. The pendant in the study blows the fuse when a bulb goes, don't know if that was a weak fuse or defective pendant (they will check it as n extra job).

I think the idea of an update and check is what drove me to it!

He already has RCD protection, though it sounds as if there is only a single RCD. This is a 1983 property. What Wiring regs were in force then ?

Because he seems to have a lot of computer stuff over and above an average person, a single RCD installation might be tempting fate.

The only time any of my Wylex rewireble fuses ever 'went' was after someone (cough) shorted something out. Ouch.

A passing electrician who thought I might be good for providing some extra business gave me a spontaneous/off the cuff quote of 'about £1,200' for replacing my 10-year-old CU last year. No discussion about what it would include/exclude and I haven't seen any need to replace the existing. He had a nice liveried van, though, for a two-man business.

It is one RCD (or whatever they are called now) per circuit, it's just part of keeping things up to date.

I have known incandescents take out fuses and MCBs, but not known such with more recent lamp developments.

MCB - Miniature Circuit Breaker - trips on overcurrent - either very short term "fault" currents, or longer terms sustained "overload" currents.

RCD - Residual Current Device - trips on a imbalance between current flowing in live and neutral (normally indicating some is returning to earth via some unexpected path - possibly you!)

RCBO - Residual Current (circuit) Breaker with Overload protection - basically a combination of the above two.

So MCB and Fuses protect the installation, and also give shock protection when combined with earthing and equipotential bonding.

RCDs give greatly enhanced shock protection by sensing dangerous conditions that would not cause a fuse / MCB to trip.

So RCDs are generally a good thing, however if one device protects too many circuits the chances of a nuisance trip increases since their "budget" for leakage current is shared across the installation. Also you lose all discrimination - any fault knocks out all of the circuits - rather than the ideal where a fault only trips the circuit with the fault.

So good reasons why you might want to change:

Current install is damaged or directly unsafe.

To replace "whole house" RCD protection (or add RCD protection for the first time)

You need more "ways" to accommodate more circuits.

You have rewireable fuses and fear they may be abused, or that they might be difficult to fix should they blow.

You have a plastic or wood CU and are concerned it might be a fire risk.

You are getting nuisance trips on RCDs and would like more RCDs or RCDs on all circuits (i.e. all RCBO) to mitigate the chance of trips.

Any chance of a photo of the current setup?

Yup, cheapo supermarket bulbs. Good quality Osram, or similar never did this (AFAIK)

A decade or two ago, I found the bulbs that nearly always tripped the breaker when they failed were Philips "Hint of ..." tinted bulbs!

nib

They have said they would fit a "Fusebox consumer unit", does that sound OK?

GU10 mains halogens were quite prone to it...

(I used to fit type C MCBs for the lighting circuits - that usually stopped it)

It's a budget brand, been going since 2017:

In theory you are only supposed to use components that the manufacturer has specified will work together, which means sticking will all one brand. eg there can be issues fitting busbars from one brand into the terminals of another. Not something that can't be worked around (worst case you could just use a wire), but less than ideal.

My CU replacement in 2021 was a similar scale job and similar price to yours, but that included using Hager components. They had suggested Fusebox but I asked them to upgrade as I may put in further circuits in future. OTOH there's been inflation since then, which maybe covers the difference.

Theo

I think this is sound advice. If I were to redo my CU today I would fit RCBOs to all 13A outlets and a main RCD of around 100mA to the whole box and use a brand that I knew would be around for as long as MK has. And leave some extra places for expansion.

Even if it cost another couple of hundred.

Are you a TT supply? I though not with your mention of replacement transformers etc ... why add a single point of potential nuisance trips?

Are MK that safe nowadays? They announced in 2019 they were stopping doing CUs, then changed their mind.

Look in the footer of

The MK brand is owned by Novar ED&S, in turn by Novar Holdings, who are in liquidation, the head office is Honeywell House, which reflects the previous owner, the UK factory at St Asaph is gone, now made in China by Yihua ...

Given the costs of labour, spending a little more on materials seems to make sense to me. Getting a bigger board with some extra blank slots costs a couple of quid more but may come in handy in case you (or whoever you might sell to) want to install heat pump, solar panels, EV charger, battery, ... in decades to come. Unless you're super tight on space it's just a few more inches in width and some extra metal, but buys you breathing space down the road.

Although MK doesn't have a good reputation these days - they were bought out by Honeywell and made cheaper/nastier (see the MK Essentials debacle). They still sell garage-style CUs but aren't a big player in the whole-house CU market any more. But I think they do still sell MCBs/RCBOs that are compatible with their old boards, so you do get that longevity.

Theo