Bosch WVH28360GB/02

Hi, this machine is a free standing washer dryer, about 4 years old.
Sometimes E17 fault code shows up. Programmes used: 60 minute wash and dry though don`t programme for the dryer bit to come on so that is a 36 min cycle and the mixed load programme.
Read somewhere that e17 boils down to slow fill but I wouldn`t say that it is a slow filler myself, water levels good, dryer is never used, pump out good..

Anyone got any ideas please? Parts too expensive to start guessing
when I`ve got no real idea and it only happening 30{e5d1b7155a01ef1f3b9c9968eaba33524ee81600d00d4be2b4d93ac2e58cec2d} of the time doesn`t help matters much either. Horrid Bosch contraption!