Here you can see some graphs from the house monitoring:
Vallox 110 SE seuranta
You can see the tank temp to sail between 44 and 47. Immersion heater backup is not currently enabled.
Some legend translation:
Tekn - room with all house techinc
Meno - outgoing water to floor heating
Palu - incoming water from floor heating
Jate - waste air after passive heat exchanger
Ulko - outside (ambient) air before passive heat exchanger
Tulo - air to house after passive heat exchanger
Pois - air from the house before passive heat exchanger
Katt - tank temperature (used for air-to-water pump logic)
Passive heat exchanger is used to preserve energy from the air drawn from the house. I had to replace the house air exchanger after Nibe compressor break.