I did try to fix it myself. There was a flash and a popping noise- and the fuses blew. I decided I'd better call in someone who knew what they were doing.
This morning I showered by throwing water over myself with a saucepan.
This is going to be a week for having the workmen round. There's a plumber in the kitchen right now fixing the leaking pipe which brought down the kitchen ceiling- and this afternoon I'm expecting an electrician to fix the shower and a heating engineer to give the boiler its annual overhaul. And then sometime today or tomorrow the builders will be arriving to start relaying the back yard.