I replaced both inlet valve and control board. I'm pretty sure the control board was bad, but replaced the inlet valve as it was fairly old and was having fill problems before getting the F1 code. The repair was still cheaper than having a repair person out to replace one of the two parts. The only issue was that the water inlet valve wiring harness was different than the original. The connectors and a couple of the wire colors were different. Also, if not familiar with the repair, it's a good idea to take pics of the old parts before disconnecting any wiring.