Sorry however, I do not understand your No.
This indicates temperature issue and/or an air flow problem due to heavy ice build-up inside the rear wall of the appliance.
Please try this to solve the issue:
Leave it unplugged and empty with door open for around 12-24 hours.
Then plug it back (expect some water on the floor) and wait for another 4-8 hours so it gets back to optimum temperature.
The problem should be resolved.
However, if the issue appears again then the problem is with defrost operation.
You will have to test/replace the temperature sensor and/or defrost heater element to resolve the issue.
Alternatively, you may call Siemens at 03448 928 999 to book repair.
If there is anything else I can help you with, please let me know.