Chip wrote:
And 6amp lighting circuits with type B breakers, so that the lights on
the stairs go out at random (quite frequent) intervals is odd too.
yes, it is a bit. Type C gets recommended here, but Bs are still the
common choice.
Type C is good yes.

I've never had an MCB trip "randomly" or even on a bulb blow.

So nothing dangerous.
I keep thinking "halfway down the stairs when the lights go out" or
"carrying a pan of boiling water across the kitchen"

That is why I have an emergency lighting unit in the
kitchen-dinette-study-lounge.

Owain