bosch fridge freezer kgu3201gb?

I have just had the same problem, and I have now cured it!

It all may be due the build up of moisture in the evaporator which clogs up with snow/ice over a period of time or the door of the freezer has been left open accidently, this allows the moisture to turn to 'snow' big time.

Unplug your freezer and check to see if there is a back panel with 4 round plastic covers, if so, remove these and inside you find clips that are holding the cover on, carefully ease of the cover.
If you find the 'snow' has covered evaporator, you will have to defrost the freezer following the manufactures procedure and you may also have to check the drainage hole in the middle of the bottom as this may also be blocked.

I hope this helps

whats is name
June 2010