I have a room which is getting too hot during winter and I want to disconnect the hot water baseboard in it from the heating system. Problem is that heating system is a loop and room is in the middle.
Do I have to open the wall and rewire the pipes behind it ? 
Is there a less extensive solution ?
Could a zone valve help here?

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  [1]: https://i.sstatic.net/LeC0H.jpg
  [2]: https://i.sstatic.net/CYy3f.jpg
  [3]: https://i.sstatic.net/uh0Ws.jpg