What kind of temperature control mechanism does the Bezzera BZ10 have?

Well this does depend on how old your Bezzera BZ10 is. Seen you have 2 model versions. There is a pre- 26-06-2010 and a post 27-05-2010 version. The older type is in it’s original configuration isn’t available anymore, for this is a relay rebuild kit available which is the same as the new model.