Evaluation of gas/condensing offer including solar thermal

Hello everyone,
I am reaching out here because I want to upgrade the heating in my house, built in '66, an end-of-terrace house with a flat roof.
It currently has an oil heating system from '93. The radiators are the usual ones, a few have the most modern control units.
I want to convert this to gas/condensing boiler with solar thermal.
I currently have two offers for this, and I would be interested in your feedback.
Offers are attached ... what do you think?
Offer 1 has deducted the subsidy (probably 40%):

[ATTACH alt="oel_gasbrennwert_solarthermie_angebot1.jpg" type="full"]47058[/ATTACH]

Offer 2 has not done this and charges an additional €1700 for the hydraulic balancing. This is not shown in the image.
[ATTACH alt="oel_gasbrennwert_solarthermie_angebot2.jpg" type="full"]47059[/ATTACH]

For both offers, the connection costs still have to be taken into account (60% of €3000).
What is your view on this issue? Unfortunately, other heating systems are out because they are difficult to retrofit in old buildings.

Would rather take photovoltaic. That is more cost-effective than solar thermal. Regarding the evaluation of the offers, a specialist will certainly get in touch.

Solar thermal gone. Not cost-effective. And the rest is, in my opinion, too expensive.

Hi guys, thanks for your answers.

I would definitely go for photovoltaics. It pays off more than solar thermal. Regarding the evaluation of the offers, a specialist will certainly comment.

I can’t choose photovoltaics because I have to replace my heating system and since 2020 only gas with solar thermal is subsidized. I don’t have the money for photovoltaics. Converting to gas condensing boiler without solar thermal already costs 9,600 + 1,800 for the connection... the additional cost for solar thermal is therefore 2,000€.

Get rid of solar thermal. It doesn’t pay off. And the rest is, in my opinion, too expensive.

That sounds interesting, but can you provide comparison figures? Leaving out solar thermal would only save me 2,000€.

You can only provide comparative figures yourself. You have to save the 2000€ first with solar thermal. I would get another separate offer without solar thermal. In offer 1, there are over 6000€ net just for the [ST]?

It is true that solar thermal "only" costs 2000 more, but whether it saves that... how do you see it? Do you have any experience? What would be the "depreciation period"?