Zanussi DA6152?

My dishwasher fills with water and then nothing. It makes a strange ticking noise as though waiting for a call. When I advance the control knob still nothing. If I whizz the control round a few times then the pump will kick in and circulate the water and even empty the machine, but then it sticks again when it refills. Engineers told me that the water pump was at fault (bl**dy cowboys). After spending £70 and fitting a new one myself it still hasn't fixed the problem.