Costs for geothermal drilling - Is it worthwhile in our case?

Being listed in the table is already good, but in my opinion, the annual performance factor must still be proven after one year. However, that could be looked up.

If the heat pump does not achieve the annual performance factor, nothing happens. According to the information sheet, the BAFA assumes that there are slight deductions from the calculated figure. You then do not have to pay back any money.

The LWZ 504 from Stiebel Eltron achieves an annual performance factor of 4.5 but also not in the annual performance factor calculator, it is about 4.0. Details on how that worked would be interesting.

We have received calculations from the manufacturer for an annual performance factor of over 4.5 and submitted these to BAFA. The calculators on the internet apparently do not take everything into account. To be honest, I did not understand the exact details, but the WRG probably plays a role in this. The LWZ 504 is a combination unit with controlled residential ventilation.