Ok apparently the part number for the connectors are:
Socket: A2502-WV04
Plug: A2502-H04
Here’s the datasheet:
1811140021_BOOMELE-Boom-Precision-Elec-XHB-2A_C57981.pdf (2.9 MB)
These parts seem to only be available from one supplier in China, I’ve ordered a sample MOQ of 50 PCS. Let me know if anyone wants some for testing?
The eventual plan is to make a little breakout PCB to sit inline between the sensor and the HP controller to intercept the signal from the Sika. It seems this exact same sensor is used in Samsung, Mitsubishi and Vaillant ASHP units, being able to read the flow rate from this sensor will enable us to monitor COP for these units without having to fit an expensive heat meter.