Alternative to Proxon air-to-air heat pump?

Just please pay the few extra euros for underfloor heating + air-to-water heat pump (or something else). With the air-to-air heat pump, you are forever and always forced to heat through the air without turning the house back into a shell. I know 2-3 houses of acquaintances, none of them are really satisfied. Especially in winter when it is really cold, the places are just somehow uncomfortable.

A quick look shows that the devices have an annual performance factor of about 2.3.

Your provider who plans this must have given you concrete information about the annual performance factor or the heating capacity and heating load.

The provider Bien-Zenker broke off contract negotiations with us yesterday after I requested the technical data for the air-to-air heat pump and the alternatively available air-to-water heat pump. The reason given was that the business philosophy does not correspond to our wishes and the trust relationship is disturbed... We are speechless.

Especially since the provider who bought the plots from the municipality awards them exclusively for Bien-Zenker construction projects. So no chance for us anymore.

They simply don’t need to deal with customers who ask too many questions right now...

But it is really crazy to then say that the trust relationship is disturbed! No words....

even if it is tragic due to the property situation, maybe it's better that it already came to a bang now. Surely, nobody needs it right now, but that is no business basis for what might be the biggest purchase of a lifetime

That's true, one may still be utterly astonished at such business conduct. That should actually be published, if the explanation wouldn't end in such Techbabbel that nobody understands...