Bosch Exxcel 1400 water level?

Last month I asked for help with my 2 - 3 year old machine, which has never filled high enough to do a good wash or rinse. Someone replied that I should turn the adjust screw a couple of turns (thanks!). Got round to taking the top off and turning the adjusters. Just a fraction of a turn clockwise has done the trick for wash level but rinse level is now way too high! Unfortunately there are three possible adjusters - bottom one for small flat blade (adjusted) and two immediately above for star/torx blade which did not seem to do anything so I turned them back to roughly their original settings. Do I have a faulty switch or can I get all levels right by turning the appropriate screw? If the latter, which adjusts what and does clockwise increase (as I think) or lower the level? The problem is compounded by the machine apparently adjusting levels dependant on load!....