GE Profile Dishwasher will not drain completely

Dishwasher Repair
1

Hi,
My GE profile Triton dishwasher does not drain completely. The water level is just over the heating coil.
Is this a common problem and could someone help me with what I should check first?

Thanks so much!
Michelle

2

I removed the filter screen from the back wall of the tub. Does anyone know how to remove the piston valve. Is it supposed to turn or pop out? I think I need to replace it. Any help would be greatly appreciated. I am a SAHM and I need my dishwasher to work:)

3

It unscrews

4

Thanks! Now if only if I could get it to budge.