Root lost after KDE user manager change

[Robert Fitzpatrick]

On 5.2, I install, startx, go in to the user manager and set my admin
user created during installation to the wheel group, exit and save
changes. Now I can't login as root after logging out. I think this
happens no matter what changes you do in the user manager, once saved,
root is gone. Does not show up in user list to start with. This is a
brand new install, thank you, so I did it again just to be sure that was
all I did. Is this well known?

-- 
Robert