Bosch Classixx won’t fill and a check water indicator is on.

Hi, My Bosch Dishwasher’s check water light came on the other day and it stopped working.
I then took off the side panel and cleared out the removable plastic pipe thing, it was slightly dirty.
Then the dishwasher worked again for one wash and then the check water light came on again.
The plastic pipe thing is completely clean and it actually fills with water when I try to start a wash but about a minute later the check water light comes on.

I’m thinking of getting a new dish washer as to get someone to call out to look at it would cost 100 euros before he/she even does anything.

But before I do I thought I’d try fixing it myself. Does anyone have any ideas what might be wrong?

Is there any steps I can take to diagnose the problem?

And does anyone know if I ring Bosch will they give me any direction/help even though it’s out of warranty?

Thanks!