We had a similar problem after my wife switched it off on going away, using the time switch, and setting it to 'off'. Somehow the heating outlet temp setting had changed to 18 degrees, so it did not need to heat the water to reach the set temperature! We reset it to a higher valuer, and the CH worked. (Ours by the way is not the same model as yours, but I expect the operating principles are pretty much the same.)
Philip Thomas, May 2007
