Costs for well or ground probe (and what advantages)

: Did you install the ground collectors yourself or have them installed?

Water Water means long-term high maintenance and trouble, if you are unlucky.

Air-water heat pump with funding could work, depending on heating capacity needs and insulation and design of underfloor heating. What is the standard outside temperature according to the new climate map from the Federal Heat Pump Association?

-14 degrees. According to the information from my heating engineer, LW is not eligible for funding. There is a parallel thread about this.