If you’re brave enough: buy and set-up a OTGW ( [APP][Pro] OpenTherm GateWay MQTT ) amnd use it to handle your Weheat.
It’s how I work it. Use OpenTherm top sens commands regarding targetwatertemp and setpoint to the heatpump decided on other parameters I get from homey..
Get yourself a Tweaker account, tthere is tons of info there…
