LWW, gas or geothermal operating cost experiences

Gas incl Solar incl
LWW approx. 3500€
Geothermal approx. 13000€

By LWW, do you mean an air-to-water heat pump (commonly abbreviated as air-to-water heat pump as far as I know)?

What should one advise now? From my perspective, it is important that even with the gas variant, planning is done with low flow temperature and accordingly the underfloor heating is installed. Obviously, a gas condensing boiler is used. And of course, every selection must be based on a heating load calculation.

The packages would need to be specified now. Is it rather the best/most expensive/most modern gas condensing boiler competing against the oldest/cheapest air-to-water heat pump, or are the offered devices on a comparable level?

Does geothermal mean brine boreholes or ground collectors?

What is the usage scenario? Is hot water used often and for a long time in the shower? Or rarely and briefly?

Also relevant for the decision: Do you have money to burn or do investment costs matter?

Which geothermal system did you choose? The deep drilling or the surface collectors? How much did your geothermal system cost you? I mean the purchase price? Regards

exactly my air-to-water heat pump, sorry for the wrong abbreviation.

the exact products would be (or similar)

- Gas Vaillant ecoTEC plus package with solar storage VIH S300 and 2 rooftop collectors
- Air-to-water heat pump Rotex HPSU compact package type 27C with 500-liter hot water storage tank
- Geothermal with brine borehole Vaillant Geotherm VWS

Ventilation system Vaillant Recovair VAR

Showers are rather rare and short (athletically active, therefore often showering outside)

We decided on a deep drilling. It went about 136 meters into the earth. The heat generator with accessories cost just under €11,000. The drilling consumed almost another €8,000. Then €5,000 was subsidized, so it’s just under €14,000 for the heating system. It’s not exactly cheap, but I didn’t want gas or an air-to-water heat pump. Regards

The difference (in terms of cost) between gas and air-water heat pumps is practically negligible, since with gas you also need the connection, which can easily cost over 2000.-. Otherwise, one can say that a house of this size, if the heating system is properly designed, will hardly consume more than 50.-€ per month for heating and hot water. Even if you only need half with geothermal energy, you can calculate yourself how long it will take to recover the 10 k€ additional costs (plus interest). By now, a new heating system should be due anyway... You also have to consider, if you want a fireplace in the living room anyway, then maybe gas is better, since the chimney draft is already available. If you accept the offer with an air-water heat pump, a chimney draft is probably not planned in your house, or it will cost an additional charge.

A fireplace is not planned. It’s nice to have but I have often read that with KFW 55 + fireplace people often open the windows because it gets warm too quickly.