Re: hotpoint dishwasher fault
DF21 is actually a UK produced machine. There is a black ‘S’ shaped hose that runs from the bottom of the large plastic fill matrix to the sump , this can get gunged up and give the fault you describe.
Having said that, I had two or three of these machines a few years back that had this fault, no matter what I tried I couldn’t get to the bottom of it, they were all on very high mains pressure and at least one of them used to work if she went outside to the garage and turned the cold water tap to the garden hose on. 😕
Best of luck.
Jim.