Im going to answer this myself after dismantling it this weekend.
1) Disconnect the kettle !
2) Prise of the very bottom of the kettle by inserting a screwdriver in the slots.
3) Remove the white outer cover which is around the base.
4) You should see where the leak is.
5) The kettle is well made with only a few parts ! The seal is a double seal which in my case looks as if it will last a good few years.
6) I identified my fault as a hairline fracture in the clear glass kettle body
Now if only Kenwood supplied replacement casings....
Bamber
September 2009