OK, but what about the rest of the price difference? Once the electrical is taken care of it should just be a matter of replacing the furnace and pulling some tubes and wires to the outer unit? You said 40k, but the heat pump itself isn’t even 10k.

I didn't say that, but it is true that in Germany it is extremely expensive, mostly due to installers being greedy.

German article, but some translation tool might help: https://www.tagesschau.de/wirtschaft/verbraucher/waermepumpe...