Thank you to those who replied. It does seem that I may have to specify what I want and pay what it costs (broadly what I was planning). As to why I ask at all, two words: sanity checking.
In some fields, the specialists buy in such quantity that they can and do undercut the high street shops, so I am not automatically assuming malpractice on the part of the electrician (although, I expect I would be paying for his time to go and fetch one, which could be avoided)
I don't know one side of a consumer unit from the other. I'm not likely to quibble over 20 quid either way, but I started with no idea whether it should cost 50 or 500 (and B&Q was no help, thank you to whoever mentioned
ScrewFix).
However - the reason I ask, in short, is to gain some understanding of what I do want, before blithely trusting the first person who is available.
The first thing I don't completely understand is, other than to put food on the tables of surveyors and electricians, why do this at all?
The arguments I hear are convenience (not an issue), room for expansion (not an issue), prevention of idiot customer using a nail when he runs out of 5amp (not an issue), and faster disconnection in the event of a problem (which may be important). What are the safety implications of doing this at all, or better still: why shouldn't I just do nothing?
Moving on to the points raised by ban-all-sheds:
1) I know next to nothing, that's why I'm asking.
2) It has no RCD protection now, so any is a bonus.
3) There are 3 circuits, 5A, 15A and 30A so presumably the CU will be a direct replacement of the fuse box.
4) It's a one-bedroom maisonette - the only conceivable expansions would be to fit an electric shower (unlikely as I have gas), or to put electricity outside (I bought petrol-fired garden tools to avoid this). It's worth having room for maybe one spare circuit, but I can't see using it.
5) I don't know that the wiring is OK, and I suspect by the age of the property that it probably isn't. It is in good condition, and the earthing is correct (had that checked when fitting a water meter), but whether I want to blow £1,000 plus to conform to current wiring regulations is a moot point. I know I can't afford to rewire, desirable or not. My hope is that a more modern CU will be more adept at shutting itself off if a fault occurs.
6) I have no problem with having an electrician supply what I need, provided that I have some *idea* what I need and what I expect it to cost. The person who tries to sell me a 12-way split-load unit in a property like this is a cowboy, plain and simple.
My conclusions so far, on which I would welcome informed opinions:
It strikes me that the whole CU would benefit from an RCD - I would sooner lose the contents of my fridge than the whole kitchen. This being said, I don't see the merit in a split load unit.
There is almost no likelihood of fitting future circuits; there is no need of expansion, I do not use electric heating, and my lighting requirements are not going to exceed 5 amps. What haven't I thought of...?
I still remain unconvinced of the arguments for doing this at all, which was more the subject of my original question than how to go about it. If the primary 'safety' argument is of people using incorrect fuses, it's just not an issue. How much better does a new CU function at interrupting a faulty circuit than an old one?
Again thank you for the advice.... my last question about acquiring the CU was something of a throwaway thought and perhaps, not central to the question at hand.
The question at hand is, do I replace it at all - which, of necessity, depends on what it costs. I do not take safetly lightly, but I also believe that prevention is better than cure and, touch wood, I haven't done anything where a better CU would save me from harm.
The only motive is safety, it's not like I have any other cause to replace it - is it worthwhile???
