Completely new heating system with solar thermal, or retrofit later

Hello everyone!

We want to buy a house that has an 18-year-old oil central heating system installed. Recently, the heat pump was renewed, and a new "pressure vessel" (is that what it's called?) has also already been ordered.

The question now is, because we want to submit the financing request, should we leave the heating system as it is, or should we directly finance a new central heating system (then in combination with solar thermal)? How efficient is such an old heating system?

We have so many questions, but somehow don't know how or where to start :(

Thanks in advance

Best regards, Marcus

Hello, the heating technician can determine through a measurement how much loss the boiler has. The efficiency also depends on whether the boiler is controlled, for example according to the outside temperature. .. is the new pump a high-efficiency pump?

Best regards Andy

Hello

After 2 days of bed rest, I can now reply again.
I am attaching 2 photos of the heating system and the pump.
I can't find anything about the heating system, and the pump doesn't seem to be very good, as I have read.



Regards, Marcus