hi,, I have a valiant combi boiler and the problem I have is the central heating stays on when it is switched off,,, on the boiler there is a switch which gives you 3 options to control the central heating. 1 heating on the timer. 2 heating on all the time and 3 heating off completely. with the heating switched off completely it is still running. there is a neon indicating when its on also and that stays off as well.. the switch seems to be part of the clock/timer unit.. any ideas?? anybody else come across this??