| I'm no plumber, but i would presume it's a build up in the immersion storage heater (or whatever you call it in the US). There's probably something you can stick in it to clean it out, but you'll probably have to drain the tank.. if you do drain it, it might be worth replacing the heater element while you're at it (the thing that looks just like the heater element in a kettle) - they are very cheap and simple to replace, and they do wear out after a few years. |