Have just bought a flat with electric water heating on economy 7 meter. The previous owner turned off the system and when we turned it on the "boost" button on the control panel is permanently lit and the water permanently on, no matter which buttons we switch to, including off. It is costing us a fortune and we have now switched the trip switch off. What could be wrong with the boost button? The summer/winter switch also seems not to work and we are not convinced that any of the sliders/settings work properly. Any help would be gratefully received.

Who installed the meter? The electric company? Whose meter is this any how? While we have timers and demand meters over here but nothing like a economy 7 meter.
It sounds like the control board's faulty. You may be looking at a replacement. Good luck, Tom