Countless "Error opening connection" errors after "Telnet connection error"

[skrue]

Hi @TheRealKillaruna ,
from time to time I am seeing the following behavior: After encountering a single Telnet connection error (probably due to a short loss of network connectivity), no data is retrieved from the Nano-PK any more until I restart Home Assistant. Instead, an Error opening connection error is logged every 5 seconds.
To me this looks like a bug in the Telnet connection handling. Would be great if you could look into it. TIA!

2024-05-09 11:16:01.644 ERROR (MainThread) [custom_components.nano_pk.sensor] HargassnerBridge.async_update(): Telnet connection error (ConnectionResetError(104, 'Connection reset by peer'))
2024-05-09 11:16:06.583 ERROR (MainThread) [custom_components.nano_pk.sensor] HargassnerBridge.async_update(): Error opening connection
2024-05-09 11:16:11.586 ERROR (MainThread) [custom_components.nano_pk.sensor] HargassnerBridge.async_update(): Error opening connection
2024-05-09 11:16:16.588 ERROR (MainThread) [custom_components.nano_pk.sensor] HargassnerBridge.async_update(): Error opening connection
......

[skrue]

After a few days of observation, it seems that the connection resets were introduced with the most recent firmware upgrade by Hargassner (V14.0HAR.o4) and happen exactly every 24 hours. So not a loss of network connectivity but probably the Nano-PK actively terminating the connection. My pull request (#26) solved the issue for me, after the connection reset I get a TimeoutError on the first retry, but the second one works and the connection stays open for another 24 hours.