Renault Clio 2001 - Rear Demister window does not work?

My Rear Demister window does not work on my Renault Clio. When I push the button, the light comes on, on the dash and and I have checked the fuse and its fine! I've even swapped it out for anpther one encase its faulty. But it still does not get hot and demist.

Any idea's?