:D Thanks for the advice, i have checked the shower consumer unit and it has a 30ma rcb with 50a mcb , am going to replace the mcb with a 40 A type B mcb as that is all that is availble for this particular unit.
As i have access to the shower cable for at least 60% i will change the cable to...
My previous shower has come to it end of life and i am planning on replacing it with a triton 300Si 9.;5KW shower.
the current circuit is a 6mm2 wire to its own shower consumer unit with a 50amp mcb, the cable is run in uninsulated stone walls through a loft space and under some very draft...