I’m not sure what you mean by 3 or 4 lines. A standard sprung return diverter valve (Normally open to space heating) can be connected to B15 (Neutral) & B17 (NO), see:
This is what I’ve got on my 5kW Gen6. However, if your heat pump is larger than about 7kW then a sprung return valve is not the best choice, they are quite restrictive to higher flow rates and the valve can get damaged due to high flow rates. A better choice for larger heat pumps is a ESBE or Honywell VC, @MWPHS stock some good valves:
From the Samsung manual:
- B17 : NO (normally open)
- B18 : NC (normally closed)
- B15: Neutral
- B16: Live (permanent live)