Heat Pump Switch Calculator Austria 2026
Does switching from oil, gas, pellets, electric heating or district heat to a heat pump pay off? The calculator compares running costs and CO₂ emissions and works out payback, savings over 20 years and net present value.
Energy & running costs (year 1)
| Item | Amount |
|---|---|
| Useful heat demand per year | – |
| Heat pump electricity demand per year | – |
| Seasonal performance factor | – |
| Old system energy cost | – |
| Old system maintenance | – |
| Old system total cost | – |
| Heat pump electricity cost | – |
| Heat pump maintenance | – |
| Heat pump total cost | – |
| Saving per year | – |
Investment & payback
| Heat pump investment | – |
| Subsidy | – |
| Avoided boiler replacement | – |
| Net extra investment | – |
| Payback period | – |
| Total saving (nominal) | – |
| Net present value (NPV) | – |
Cumulative saving over the horizon
CO₂ balance
| Old system emissions per year | – |
| Heat pump emissions per year | – |
| CO₂ saving per year | – |
| Total CO₂ saving | – |
Year-by-year overview
| Year | Old cost | HP cost | Saving | Cumulative |
|---|
Note: An estimate for orientation, not a binding economic assessment. The actual seasonal performance factor depends heavily on the building, the heat emitters and the flow temperature; energy prices and subsidies change frequently. The large federal subsidies closed to new applications in mid-2026 – check the current status with KPC, the Climate and Energy Fund and your federal state. Get several quotes and independent energy advice before deciding. All figures without guarantee.
Does switching to a heat pump pay off?
From the old system's annual consumption the calculator derives the useful heat actually needed via its efficiency. Divided by the seasonal performance factor (SPF) this gives the heat pump's electricity demand. The saving is the difference in running costs – energy plus maintenance – with fossil energy and electricity projected forward at different rates of increase. Investment minus subsidy (and, in "boiler replacement" mode, minus the price of a new like-for-like system) gives the extra investment and hence the payback period.
The performance factor is decisive
The SPF states how many kilowatt-hours of heat the heat pump delivers per kilowatt-hour of electricity over the year. An air-to-water heat pump reaches around 3.0–3.5 in an older building with radiators, and 3.5–4.5 with underfloor heating and a low flow temperature. Ground source is usually 4.0–4.5, groundwater 4.5–5.0. The higher the SPF and the wider the gap between the fossil energy price and the heating-electricity price, the faster the payback.
Default assumptions used (as of 2026)
| Assumption | Default value |
|---|---|
| Heating oil / gas / pellets / logs | €1.10/l · 11 ct/kWh · €330/t · €95/rm |
| Household electricity / heating tariff | 23 ct/kWh / 20 ct/kWh |
| Turnkey investment | Air-to-water ~€24,000, ground source ~€34,000 (incl. VAT) |
| Seasonal performance factor | Air 3.3 · ground 4.2 · groundwater 4.8 |
| Fossil / electricity price increase | 4% / 3% per year |
| Emission factors (g CO₂/kWh) | Oil 266 · gas 201 · pellets 23 · AT grid mix 156 |
| Time horizon | 20 years, discount rate 3% |
Sources: investment and operating cost ranges from Austrian installers and energy advice centres (2026), emission factors from the Environment Agency Austria, subsidy information from Kommunalkredit Public Consulting (KPC) and the Climate and Energy Fund.
Frequently asked questions
- What is the seasonal performance factor and why does it decide everything?
- It states how many kilowatt hours of heat the pump delivers per kilowatt hour of electricity across the year. An air-source pump in an older building with radiators realistically reaches 3.0 to 3.5, with underfloor heating 3.5 to 4.5; ground source is 4.0 to 4.5 and groundwater 4.5 to 5.0. The higher it is, the lower the running cost – it enters the calculation directly as the divisor for electricity use.
- Does a heat pump work in an unrenovated older building?
- Yes, but the flow temperature it needs decides whether it pays. The higher that has to be, the lower the seasonal performance factor. A good test before replacing anything: turn down the heating curve on the old system and see whether the house still gets warm at a flow temperature of 50 °C. Larger radiators in a few rooms are often far cheaper than a full renovation.
- What does the mode „boiler replacement due anyway“ mean?
- In that mode the calculator counts only the additional investment over a new heating system of the same kind, not the full cost. That is the honest comparison when the old system is at the end of its life: the alternative is not zero cost but a new boiler. Payback time becomes considerably shorter as a result.
- Are there still subsidies for replacing a heating system?
- The large federal programmes „Sanierungsoffensive“ and „Sauber Heizen für Alle“ closed to new applications in mid-2026. Some regional and municipal schemes continue and vary widely. Enter the amount you realistically expect – the default in the calculator is only a placeholder.
- Does switching pay off without solar panels?
- Usually yes, though a PV system improves the case considerably because it supplies part of the pump's electricity at generation cost rather than grid price. The effect is largest in spring and autumn; in winter, when the pump needs most, PV delivers least. The solar calculator on this site uses the same methodology, so the two results can be read side by side.
Sources and further reading
- Umweltförderung des Bundes The agency administering federal subsidies for heating replacement and thermal renovation, with the current status of each funding call.
- klimaaktiv The climate ministry's initiative, with manufacturer-independent planning guides for heat pumps.
- E-Control The tariff calculator for electricity and gas – find the heat pump tariff that determines your running costs here.
- Klimaschutzministerium The legal framework for replacing heating systems, and the reports on energy price trends.
- Klima- und Energiefonds Federal programmes covering heating replacement, photovoltaics and storage.
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