Header in Theme typal.makewp005 doesn't appear

Hello,
I use the Typal theme (typal.makewp005), but from the beginning (since I downloaded this theme) the default header doesn’t appear. There is no header at all. When I try to upload my own header, it doesn’t appear either. I wonder if someone can help me with this?
Thanks!!
Marloes
My website is http://www.praktijkbalsem.nl.