I bought a new flat and I think there's a problem with the hot water because it is piping hot. There's no way to turn it off even when we turn the timer to off, the water is still being heated by the immersion heater (the immersion is the only way of heating water in the house).
Can a faulty thermostat do this? I noticed that there was leaking in the element assembly and the element place assembly is significantly rusted. I'm not sure if this could have shorted the timer device.
Anyway, last week, the heater stopped working and the tank is stone cold. Either the thermostat died completely and failed safe, or the cut-off has kicked in to turn everything off.
The element is mounted on the side about 1/3 from the bottom of the tank. The whole system is an unvented system with a pressure tank on the top. Is replacing the element a suitable DIY job?
I imagine it's just a case of loosening the element with a giant spanner, then draining the tank to below 1/3 level and then taking out the old element completely and replacing it with the new one (I'm assuming element, thermo and cut-off are all integrated).
Is there anything I need to watch out for? I've never dealt with a pressurised system before. Also, how much should it cost to get this thing done professionally?
Lastly, is it worth replacing the whole tank. If so, how much more should this cost? Thanks for any help/advice.