The fill period is timed, usually 2 mins. Normal fill level is *not* controlled by the float. The float is for overfill protection ... for example in the event that the wash water doesn't fully drain, the next fill of 2 mins for rinse would overfill the tub so the float shuts the water off before that happens.
Normal fill level should touch the heating element, if not slightly cover it.
There is no adjustment screw for the water pressure or fill level. You may be confusing that with some models of washing machines.