Update: Pulled the heater valve from the parts car, looks to have been replaced with a new Bosch unit at one time. Pulled my current unit out, while in the process one plastic hose barb pulled out on the unit. While inspecting I noticed a crack down the side of the plastic housing. So... my old unit would drain coolant over night leaving an air cavity that would not fill until pressure and driving. New unit clicks and the pump works so I will see if it gets heat in the morning. I did not check the old unit at all.