I spilled a small amount of wort while mashing, and then the lights and sockets went out in my kitchen. I went to the cupboard under the stairs and turned the fuse switch thing back on and the kitchen came back to life. I went to turn my ACE boiler on [which had been off the whole time] and got a shock off of it. I never had a mains shock before, scared the bejesus out of me. Anyway I turned it back on from a distance, using a wooden spoon, and it seems to getting up to boil ok. Guess I'll just have to remember not to touch any of the metal parts of it in future.