The data

What do combined_* / running_* / space_* / water_* actually average over — and specifically, does space_flowT_mean exclude hot-water cycles entirely, and how is the distinction made?

What does quality_* measure, on what scale , completeness, or plausibility too? (With the concrete version: would a sensor reporting an impossible value consistently still score high?)

Confirm the temperature fields are °C.

The distinction is made based on the DHW status sensor feed state. The exact processing code is available here: app/apps/OpenEnergyMonitor/myheatpump/myheatpump_process.php at master · emoncms/app · GitHub

Quality is purely a null count / total data points count for a feed app/apps/OpenEnergyMonitor/myheatpump/myheatpump_process.php at master · emoncms/app · GitHub

Yes all °C

The quality fields are used for this ui element on the system view page, which has a better title “coverage” rather than quality.

E.g: https://heatpumpmonitor.org/system/view?id=748

Thank you so much Tristan, this is incredibly informative.