If we associate a device with a storage room

and we need to remote that value using the API, there is a hidden option to do that:

storage_room_id=D42_NULL

the complete call will be the following:

curl -k -X POST -u 'admin:pass' -d 'name=XCC-7X99-S4ADA035&storage_room_id=D42_NULL' 'https://D42-IP/api/1.0/device/'

and here is the result