Thing is possessed. First time I've had this problem. The dispenser will randomly come on, you can here the flapper pop, pop, pop, pop, then it will stop. Sometimes it only pops once, sometimes it will go on for 6-7 times. It will just randomly do that. I have it set up in my showroom, just letting it cool.

I have tried replacing the whole assembly (flapper, motors, switches, etc), with a known good used assembly, but same thing happens. Tried to use Google, found nothing except people saying it's the water valve. I thought it would be unusual that would happen.

I'm not a novice by any means, but this is a new one on me. TIA for any help!