HGI80 missing hot water temperature all of a sudden

[Jabes]

I have had my Evohome HGI80 configuration working for a few weeks, and it's been great. I also am syncing settings from the evohome web api.
Just over the last couple of days my Hot Water temperature from the HGI80 has stopped reporting. The main evohome controller is seeing it and I'm getting the results via the API.

I have tried moving the HGI80 slightly (it hasn't moved more than a few inches in the intervening period) but not been able to get the readings back.

Is this likely to be a coverage issue or is there perhaps some other reason why the HGI80 wouldn't get the messages? I see a few errors in the log but not enough that would imply anything particularly wrong.

[Jabes]

Rather than leaving this unanswered, I thought I would share the solution to this problem.

Domoticz doesn't spy on the messages that come directly from the CS92 (although it could) as these are not easily associated with a particular installation. Instead it sends a message to the controller asking it what the hot water temperature is, and captures the responses to this.

The HGI80 can get into a state where it no longer transmits messages (perhaps caused by it being asked to send too many within a short period of time). Rebooting the machine won't stop this, the HGI80 has to be powered down - in other words unplugged or the machine it is connected to turned on/off.