My washer just stopped working and displayed the F30 code and made a continuous sound like switches trying to switch or a pump trying to pump. The water is fairly hard here and the machine has been in service more than 3 years. I found a solution:

Removed the dispenser and thoroughly cleaned it.

Put my hand all the way into the dispenser cavity on the machine and felt around on the top all the way at the back. There are moveable parts back there that were hung up. Felt like a circular plate that moves back and forth. I believe it was hung up because of the hard water. Once I freed the moveable parts up with my hand, I was able to restart the load and the machine has been working fine for a couple of days now.