NIBE onboard monitoring accuracy

I’ve been monitoring a NIBE F2040 12kW with SMO S40 controls with a MID approved heat meter and an emonTx V4 with emonVS voltage sensor.

The good news is that the onboard monitoring of the NIBE seems to match the independent OpenEnergyMonitor data very closely.

It seems the NIBE onboard electricity monitoring includes the power used by the circulator pump and the indoor controller, the onboard monitoring electric energy readings were 0.4% higher compared to the OpenEnergyMonitor emonTx V4 readings.

The onboard NIBE heat metering was on average 0.13% higher than the independent Sontex MID heat meter.

This resulted in the NIBE onboard COP being 0.27% lower than OpenEnergyMonitor independent data

Note: While these results indicate that NIBE has accurate onboard monitoring, these results are specific to this system YMMV. A poorly attached temperature sensor could result in very different readings. Also, this system does not have glycol, as far as I’m aware there’s no option to calibrate the onboard monitoring with the specific heat of the glycol mix, therefore the readings from systems with glycol maybe less accurate?

Here’s all the data:

The OpenEnergyMonitor data is available on here: