Ideal classic boiler keeps turning itself on?

I have an Ideal classic bolier, which has just been serviced. and no problems found. However since then I have noticed that it keeps turning itself on, even though the timers are set to off !!! This is very strange, and at first thought it was some kind of frost protection, but it has not been that cold. It does this at all times of the day.
Im thinking maybe the electroncics have got screwed up somehow.. any ideas would be appreciated