Called Kohler, they are sending a new PBU and mixing valve, wonderful people, stand behind they're warranty. After the phone call (and work) I decided to try something new. I removed the PBU, reinstalled the mixing valve and turned the water supply on. Still no joy. Removed the mixing valve. Then dragged a small air tank up to the shower and blew out the line from the shower arm back. 20, 30, 50, 60 psi no luck finally at 80 psi a big splash of water (and some crud) came out of the valve body. As it turns out there was a blockage in the line from the valve to the shower ell. Reinstalled the mixing valve without the PBU and turned on the supply. I could hear (from the basement) the flow, I had water flow! Flushed the lines with about 3 gallons of water and turned off the supply lines. Reinstalled the PBU, clocked 180 degrees from the last install, installed the mixing valve and turned on the supply. Water flows from the shower! I had hot and cold water running and could control it from the shower valve. Moral of the story, don't wait 5 years to use the shower. Thanks for the help, I've been a guest on the forums for long time and learned a lot.