Which heating is recommended for KfW 55?

Yes, of course a brine heat pump will have lower consumption. However, the opposing costs of about 20,000 euros more investment also add up significantly, and as I have had to learn, one must expect high maintenance effort and corresponding costs for the heat pump. Regards

I don't believe that the additional effort is really high - for that price you already get the entire system. Besides, I wonder what maintenance you mean!?

Yep, I agree - but so far you mostly read more about "hearsay" about him

And always orienting yourself to the KFW stuff - are you even aware that with Kfw55 the calculations and thus the costs are significantly more complex/higher?

What do you think, why did we still choose Kfw70 for KFW56?

I don't think the additional effort is really high - for that price you already get the entire system. Besides, I wonder what maintenance you mean!?

I mean the tightness test, which is omitted in closed systems, and possible adjustment costs that some companies charge to optimally set up the system.

Even with air-to-water heat pumps, reserves for repairs need to be formed, since the heat pump is a highly technical system that, after all, has to heat from -5 degrees (air) to 40 degrees (water) in winter, for example. These are processes where the pump has quite a bit to do. It should be clear that this does not go without maintenance or consequences. The pumps are susceptible at the evaporator (air heat exchanger). According to the information from my heating engineers (who do nothing all day but install heat pumps), the material cost alone is about 1300 euros for the heat exchanger, which can already break after 5 years.

Then you shouldn't choose the heating engineer if he installs such rubbish

Again: There is no maintenance - or do you also maintain your refrigerator?

And what leak test? On the brine circuit? The drilling contractor does that and it's included in the package... and every heating system needs to be adjusted.

How often does your freezer break down? The poor thing even has to produce minus 18 degrees at plus 30 degrees.

And the gas condensing boiler even plays with fire, it definitely has to be regularly cleaned from soot and the like. The maintenance intervals for a heat pump are rather longer.

A 6 kW brine heat pump costs about TEUR 10 plus source.

With BAFA funding, a gas condensing boiler has a hard time.

BAFA funding is only available for existing properties.

With the developers of my choice, I always have an additional cost of 9-10 thousand euros compared to the gas boiler. A brine system costs about 15,000 euros + earthworks (laying collectors, etc.), I easily reach 20,000 euros.
Earth drilling per borehole 5,000-6,000 euros...

Regards