Can a gas condensing boiler be built to KFW-55 standard?

Good evening,

we currently have an offer for a prefabricated bungalow. The seller has suggested installing a gas condensing boiler instead of an air/water heat pump. It is the more cost-effective option. It is said that this will still meet the requirements of KFW 55 and qualify for the €18,000 subsidy.

Has anyone had any experience with this?

Grant or no grant. How big is the cost difference? For my taste, electricity should come before fossil fuels. It is also an ideological question…

I have already dealt with that as well, we would prefer a gas boiler to avoid the terrible box in the garden.... GU 1 says it doesn't work with KW55 and he doesn't do it at all... GU 2 says it works easily if combined with [Solarthermie] and with ventilation and heat recovery, price-wise then similar to heat pump... But I don't know what is true.... GD

Basically, it can be accounted for. But I would rather recommend a heat pump. If only the box outside is disturbing, I believe there are also air-water heat pumps without outdoor units. Or how about deep drilling or trench collector?

If only the box outside is disturbing, I believe there are also air-water heat pumps without outdoor units. Or how about deep drilling or trench collectors?

I think indoor installation can get very loud very quickly or quite expensive (soundproof door, etc.). Deep drilling would be great but would exceed my budget...
Best regards

There are also attractive casings for the outdoor units.