Initially, I tried cleaning drains with soda/vinegar/boiling water which cleaned it well but didn't correct the problem. I then saw video clip about the piston valve, checked it out and found that mine looked like "this is a bad one"...Ordered the part, waited two days enjoying the zen of hand washing dishes, put the new part in and turned it until it locked in place, screwed four nuts/screws back in, and voila, it was done!!! ---All by a 60+year old girl who doesn't know the difference in a nut and a screw when it comes to fixing things! And my well used 10 year old GE is back in service, and I have new found confidence in my abilities! Thank you for your help!