Calculate the annual performance factor (Jahresarbeitszahl) based on electricity consumption?

Has the heat pump been subsidized by Bafa? Then you should also have a heat meter; otherwise, there is often a menu item for generated heat or something similar. It is rather inaccurate but better than nothing. Otherwise, you have no way to check which annual performance factor you have achieved.

Without a heat meter, you cannot determine the annual performance factor. About 2000 kWh for heating doesn't sound bad, but it could mean an annual performance factor of 3-6...

When you calculate the annual performance factor, you take the total kWh and total heat quantity, right? For example, with us, the hot water consumption is almost 50% of the total heat quantity.