Figured it out. I had to send HVAC_FLOW_STATE to HA, in order for it to figure out that it was a "thermostat". Only problem is that it shows up with states "Auto" "Cool" "Heat" and "Off" in the dashboard, even though I only have the possibility to heat, or turn it off.
Same issue here. HA receives data from Ethernet Gateway for only a few minutes and then:
DEBUG (MainThread) [mysensors.gateway_tcp] Connection lost with <_SelectorSocketTransport closing fd=42 read=idle write=<idle, bufsize=0>>
I also have MYSController connected to the GW and it remains connected. There is an open issue as others are also having the same problem. Am wondering if anyone here is having success with Ethernet Gateway connected to HA.
What I did not try but might work: copy your persistence file, delete the old GW and create a new one with the persistence file you copied. Maybe the devices are preserved like this. Maybe you should create a full backup before...
<edit: typo>
