You can’t use the root user when SSH’ing to WHM but what you can do is issue a SU command once you’ve logged in with another user which isn’t root. On some occassions, you may encounter a no permission error when doing this.
Problem: Help! I can’t seem to login as root in whm so I need to do a SU command instead but i’m getting a permission error!
Answer: In your whm panel, access Security Center -> Manage Wheel Group Users and you will be able to assign the username to the group that allows SU
And that’s the solution to your problem!