DeDietrich dishwasher water not circulating?

My dishwasher programme stops at the point where it should circulate water, the tablets are not dissolved nor is threre evidence of water in the machine.
I can hear the machine open the taps and the sound of water entering the machine but it doesnt seem to get past the pump.
My question is, is this a pump problem or a programming problem?
the machine is an integrated unit, I cannot see a serial number or model name but it is dedietrich make approx 4 yrs old
Thank you,