As stated in the main post I triple checked the by-pass, I even pulled it. The valve is fine.
When I get home this PM I'll fill the system back up & try again.
I'll post the results along with the make/model.
When the by-pass is in the Normal mode Deb gets a quick shot of HW but then goes cold.
I'm unable to COMPLETELY pull the cover over the HWH. I beed to trim some shelf supports to get the cover off. Ths "ant scald" looking valve Looks almost like a rotatable dial, Kinda like an inverted plactic shot glass.
I'll supply some PICS
Thansk