Phil L
if the house is only 7 yrs old, you will need a breaker (mcb)

I don't understand. Are you saying that an mcb would not be required on
older houses?

If I should have mcb's for everything rather than fuses, I could
replace them all.


David Hansen
What sort of fuses are they?

I don't know how to answer that. What types are they? They are just
larger versions of the types you get in a fused plug.


You will probably be able to re-use the carrier as 40 and 45A cartridge
fuses are the same size.

If I upgrade the fuse from 40 to 45 amps, isn't that putting the cable
at risk? Note that I have been running a 9.5 kW shower on a 40 A fuse
for the last two years. Surely that means it is fine?


The consumer unit is made by Wylex.

The shower and socket circuits are covered by an RCD: Wylex WRS80/2
rated at 80 A, 30 mA. The other circuits (e.g. lights) are not covered
by RCD. The whole board has a chunky red on/off switch.

I can't see any part of the cable and I do not know its size or its
route. The consumer unit is at the front door and the shower is in the
centre upstairs. The cable is probably 5 to 10 metres long.