I seem to have a hot water cyclinder that is always very hot to the touch (I'm sure I could crack a joke about my wife in that as well, but I'll leave that for another forum)
I noticed this as particularly strange when the gas boiler was not working for a few hours and yet it was still very hot - the manual switches for the sink/bath and on/off were at sink and off (in truth we never use these switches). When you turned the switch from off to on, the light came on, so it looks that it is not a case of the cylinder being permanently on by a wiring problem (on the surface of it).
Basic questions - has anyone ever come across this before?
Is the cylinder lagged? If so (especially if factory lagged) then it would not be surprising for it to retain a significant amount of heat even after the central heating has been off for a few hours. If you leave the central heating off for an extended period of time and maybe use a lot of hot water do you find that it cools down?
If a factory lagged jacket is the kind of solid foam, then, no, we don't have that - it is the type that you can pull off it if you had too, but it covers it well enough - I'll just have to be check it when the heat has been off for a while and see if it is just an incredibly efficient heat retaining cylinder before I go any further.
remove the immersion cap and place a phase tester on the element connector, if it lights up when the switch is off then you have a wiring problem behind the switch.