the base...where the coil screws in at, the glass can be removed from that its secured by an o-ring but it seems like sometimes its not put on quite right and it gets stuck. if you play with it, it will eventually come off and then i took the o-ring itself off and reseated it on the base and that seemed to help alot.
Ok thanks.
What i also noticed was the top gasket / o-ring was in the incorrect way from factory according to diagrams I have found...... see below where the flat bit of the top gasket is facing up and the indents on the sides face down. Mine was the opposite when I removed it from the top hardware.
I've switched it around now and reseated the bottom gasket / o-ring as well. Just need to fill up with some juice and give it a go.