So, here's where we may see this hyphen: 'centrally-heated' (5)
I believe the answer is:
hence
'so' is the definition.
(thesaurus)
'where we may see this hyphen centrally-heated' is the wordplay.
'where we may see this' indicates the answer is hidden within the clue.
'HENCE' can be found hidden inside 'hyphen centrally heated'.
'here's' acts as a link.
(Other definitions for hence that I've seen before include "Therefore, consequently" , "From this time, or for this reason" , "It follows from that fact" , "For this reason; in the future" , "As a result" .)