Heating engineer help?

[Mtnboarder]

Can anyone help with my heating problem- I've got white meter through Hydro-Electric and the overnight hot water hasn't worked for a while, although the manual boost is fine. As these are separate elements in the tank I left it until last week when the plumber was fitting a new bathroom and got it changed while he was here. Still no joy though.
The only other component of the system is the control unit- this was changed in April when a new kitchen was installed so is unlikely to be the problem. Any ideas? The storage heaters work so the signal into the meter seems to be ok.

[ferg]

Does the new element have a manual reset hi-limit stat?? If so it may need resetting. Push the tiny little button in the centre of the stat. (Not the big rod-stat like elements have always had)