I emailed Samsung tech support with this email:
I have installed a Samsung Joule R32 16kw ASHP (AE160RXYDEG) and cylinder (HUGH-G63013-3C) and I am trying to get it set up for cooling.
Can you please advise how this should be done? I believe terminals B21 and B23 call for cooling when they receive a 230V signal but can't figure out what else needs to be done to get the system to switch over properly.
And here's a screenshot of their response