New electric shower - old fuse box | Overclockers UK Forums Jul 03, 2014My electric shower needs replacing but my fuse box is old with rewireable fuses. Current shower has it's own 30amp fuse within this fuse box. I hear it is now illegal to wire up new showers this way and they must have an RCB or whatever. Shower install, old fuse box | DIYnot Forums Oct 28, 2008I'm looking at installing an electric shower in my house. I've had a look at the fuse box tonight and its a very old thing (It looks a bit like a "memera 3" i found on google but has 6 fuses rather than 4) with replaceable fuse wire and 4 pin fuses.