diplomat dishwasher stops after 30 minutes,?

just moved into this house which has integrated diplomat adp 8322 model.dishwasher.
however after 3 months its started playing up, after running for approx 30 minutes, it makes a noise and stops, on opening the door ,the light is on the rinse cycle instead of wash and the start button is flashing. have tried pouring boiling water down into the sump as was suggested in another site but no joy, can any one help. ??