Warning: This is a minority-interest geeky post! A Fortic Tank is not military item with tracks and a few bangy accessories. It's a sort of hot water tank and fits in an ordinary airing cupboard. Indeed, that's where I first met one. I'm sorry to disappoint those hoping for a story of romance in a plumber's merchant. It's still an interesting story though and as in the Hitch-Hikers Guide to the Galaxy, someone ends up with a bruised arm. In keeping with the tradition and to maintain the suspense, the leftness or rightness of the arm will not be disclosed until later. Anyway, every now and again, the immersion heater fails. The first time this happened was a learning experience. I turned off the cold water and opened the hot taps to drain the thing. Next I applied a huge spanner to the heater element and after a lot of banging and cursing got it to rotate. As I did this a few drops of water oozed out. I turned it some more and as there seemed to be a growing tric...