Will you not open the door?
That could be a request for the listener to open the door. But could it also be a request for the listener not to open the door?
Will you not open the door?
That could be a request for the listener to open the door. But could it also be a request for the listener not to open the door?
The question will be interpreted by English speakers as a politely-framed request for the door to be opened.
More often, people would say: "Won't you (please) open the door?" as "will you not" sounds rather formal.
Anyone who wanted the door to remain shut would usually say: "Please don't open the door" or "Please leave the door shut/closed".
So while the request is capable of being interpreted differently, in practice it is unlikely to be.