Just putting this up before I send a support ticket and waste some GM's time.
I know how feeding works, you select a material, make sure your sprite sill has some appetite and click the feed button.

Let's see here..
The heat level on my sprite is full, taking it on the clockworks doesn't put any heat in it and clicking on any materials on my inventory isn't doing anything.
Tried logging on and off, restarting steam, nothing.