Smeg DWF664

Smeg D/washer 4 light model, has 1st & 4th light lit (which indicates water level incorrect/overfill base float safety diaphram activated), have checked air chamber etc all seems ok,no water in base, It wont let me cancle the code I have pressed the start/pause button for the time indicated in book but its not resetting, has any one had problems resetting these or with the pressure switch on this model? (the metering box is clear customers using descaller ofton)

This model is under insurance and has had a number of repairs done to it a least 3 pcbs, one of those in first year, leaking motor , jammed pump, dispenser theres not much that hasnt been replaced!

Can anyone help many thanks

Steven