Difference between city water meter and apartment water meter

Yes, of course you are... but the meter must also fit the size of the house... if one that is too large is installed, then it simply registers more than was actually consumed...

Yes, of course they are... but the meter has to fit the size of the house... if one that is too large was installed, then it simply registers more than was actually consumed...

Well, for us it is like this: the 'water meter of the municipal utilities registers a higher consumption than the meters in the apartments. I assume that the plumbing company knows what it is doing.

No one will be able to answer you helpfully if you do not even know for your own house whether the sub-meters actually capture all consumers...

xxx.molline.de/fileadmin/content/abrechnung/Infothek_Abrechnung/Information_Differenzen_Wasserabrechnung.pdf

I found something. I will also check with the installation company. They often work in the neighborhood.

Your descaling system also consumes a larger amount of water during regeneration. Since this happens before the sub-meters, this amount is already missing.

Morning

That won't work like this.
You first need an overview / wiring diagram to know which consumers are connected where or which meter they run through.

Turn off the two apartment water meters and see where water is still running.
These consumers, including certainly the water softening system, are then only recorded by the supplier.

That makes sense, since these amounts cannot be assigned to the individual apartment user.

Olli