Dishwasher Diplomat HJA 8630 - how do I get it to rinse the dishes?

Diplomat HJA 8630 dishwasher has stopped rinsing the dishes - I added salt 2Kg - even though I live in a soft water area - I have tried using different tablets and still no joy.machine only 5 months old. How do you know if there is enough salt in the machine - I added more salt but it seemed to be full - the salt light in on constantly -anybody help please. It was working ok up till now - I mostly use the 35c wash cycle