This is where the information that electricity metering is MID originated:
My 10 kW arotherm apparently has a wilo pump:
As far as I am aware there is a separate flow rate sensor in there as can be seen on this system diagram (18 - Durchflusssensor = flow sensor). I have no information on manufacturer or model of this sensor, though.
This thread here contains most of the Vaillant metering accuracy discussion:
