I recently bought a Fibaro HC2, and now I want to connect my (old) Duwi Z-Wave Insert Dimmers to the HC2.

I am having some problems doing this ...
What is the exact procedure to do this?
This is what I did:
1) Get the Fibaro HC2 into learning mode
2) pressed the buttons (both of them) more than 3 times)
I wonder that maybe the range is a problem, or are the Duwi Z-Wave Insert Dimmers not compatible?