Start button light flashes 6 times then pause and continues to flash 6 time?

My diplomat dishwasher starts a cycle, any it doesn't matter which, runs for around 30secs then bleeps continually with 6 light flashes pause then 6 again so on and so forth until you open the door, then the beeping stops but the lights continue.

Engineer came and had a look, waggled the water pipe and it started working, (got lucky i guess), but since then the problem has returned. Have tried adjusting the water pipe to no avail, can anyone offer any advice? Model no. starts ADP 83 but can't remember the rest at present. It appears to fill with water, but doesn't sound as if the water is getting pumped properly. Any help would be greatly appreciated.

Cheers
Matt