First thing is to remove the SD-Card from ThermIQ. It’s no longer used.
Second thing is to make sure you have the latest Thermiq-firmware. Check the current FW-version under “Settings/Main”. Current version is ThermIQ2 v4.35 0096. Upgrade if necessary
Third thing to try is to login to your Raspberry and type sudo picocom /dev/ttyUSB0
This will start a terminal towards the ThermIQ card where you can test it with direct communication.
To get firmware verion and confirm that USB-com is working
To confirm communication with the heatpump. If the later fails please check your connections with the heatpump, make sure that the ThermIQ card is in between the main-controller and any extension boards.
Also do a restart of the heatpump.