My house was built in 2004. I bought it in 2007, delighted that everything was brand new and had at least 10 years before anything would need replacing. Last autumn (October), I happened to look at my hot water tank, it is shut away in a cupboard and had given no cause for us to look at it. There were streaks of rust down the side and I could see a drop of water alongside one of the pipes. I called the local plumber immediately. The plumber said that a 'diode' needed replacing. That I should be sure to keep an eye on the tank in case... read full review »