Heating system replacement for existing property, year built 1993 - Offer evaluation

Hello dear house building community.

I have been a silent reader so far and have already taken one or another very useful tip from this forum. Now I need your help.

We have acquired a existing property built in 1993. Currently, the old oil boiler with 20KW is still installed and urgently needs to be replaced,
as the entire installation in the heating cellar has also "aged".

The following basic information:

80m² with underfloor heating from 1993 (ground floor). The ground floor is additionally equipped with radiators in every room.

80m² with radiators (upper floor)

According to the consumption certificate, approximately 3000 liters of heating oil were consumed per year. 450 liters for hot water demand.
Additionally, 3500 kWh were heated per year from the tile stove.
We have already renovated the tile stove (warm air) 9-18kWh Kaschütz.

Building information:

Double-glazed plastic windows
36cm exterior wall Pori-Klimaton
Fully basemented. One room in the cellar is developed as possible living space.

Insulation condition:

Attic and roof: rafter insulation glass wool approx. 16cm
The roof windows are in poor condition and will have to be replaced by us soon.
What is not helpful for the energy balance of the house is an open cellar staircase / gallery from the cellar to the upper floor.
There is also a fire protection door to the outside for the cellar access at the staircase in the cellar, which is a great cold bridge.
Additionally, the wooden house door is in poor condition (warped) and will also be replaced by us soon. Windows are in great condition.

Possible future investments:
- Basement ceiling insulation
- Closing the cellar access (drywall) to prevent cold air draft from the cellar in winter: alternative replacement of cellar door (complex)
- Photovoltaic system (9-12.5 kWp)
Long-term: Roof insulation, window replacement

Unfortunately, we do not yet have reliable own experience in the house and are now forced to act due to the failure of the heating system.
Otherwise, the condition of the house is very good, so we do not plan major renovations.
The heating room is very large and storage of pellets is not a problem. Also, the installation of a heat pump is no problem due to the property. No gas connection.

The following options were offered to us by different heating engineers:

1) Air heat pump with 10 KW (Wolf) plus 800-liter fresh water storage plus renovation of all radiators to low temperature. (Subsidy 50%)
2) Pellet boiler Ökofen condensing with ZeroFlame plus heating rod fresh water storage 800L (Subsidy 55%) --> Currently our favorite
3) ETA PU 14 plus heating rod fresh water storage 1000L (Subsidy 50%)

The investment costs are approximately in the range of 38k for both projects (minus subsidy). Both offers include a softening system.

After careful reading here in the forum, I am now considering bringing forward the photovoltaic system as an investment in order to possibly bridge the pellet heating in the summer months with a hot water pump.
I would then install this in the cellar to also increase the self-consumption rate.

I look forward to your opinions. Best regards and thanks in advance!

1) Air heat pump with 10 KW (Wolf) plus 800 liters fresh water storage plus renovation of all radiators to low temperature. (Funding 50%)
2) Pellet boiler Ökofen condensing with ZeroFlame plus heating element fresh water storage 800L (Funding 55%) --> Currently our favorite
3) ETA PU 14 plus heating element fresh water storage 1000L (Funding 50%)

How do you get such high funding? Aren't you always 5% too high?

P.S. Without any further energy measures, I would not choose a heat pump and a photovoltaic system is always worth considering - regardless of which heating system you have (pellets with domestic water is of course a double investment, the heat pump alone can do better in summer).

Why is the replacement urgently necessary? Like really urgently necessary? Because everything is old and looks worn out, or because something is defective. First, I would carry out all the planned energy-efficient modernizations in the upcoming summer half-year. Additionally, I would address and implement the issues of heating curve and flow temperature. Then, during the winter, determine the actual energy consumption and find the lowest flow temperature. Act accordingly by next spring. Otherwise, if it is urgent, I would not commit to a heat pump, as it will be inefficient and therefore expensive at the probably high flow temperatures. I also consider €38k to be an OUTRAGE. Pellets as an alternative are possible. Basically. Only you don’t gain any space. Is gas not available? Photovoltaics can be chosen completely independently of the heating system.

Basic funding of 45%
iSFP is currently being prepared for us +5%
For pellets, the Ökofen Condens with Zeroflame would receive the innovation bonus.

Reason for the renewal:
- Expansion vessel broken.
- System is losing water.
- Exhaust values are okay.
- During maintenance, a "detachment" of the base and a critical condition of the blower were detected in the burner.

iSFP are currently being created +5%

OK - I didn't think about the schedule. Then you are obliged to work through the points of the schedule.