The big question every homeowner asks: "When do I get my money back?" In 2026, the answer is pleasantly short: With the hefty KfW funding, often in under 5 years.
No dry Excel spreadsheet, but clear numbers, a real case study, and practical tips so your heat pump starts showing "black numbers" as quickly as possible. And yes, the state helps massively.
Three factors decide how quickly your heat pump pays for itself:
Funding, up to 70% KfW grant (KfW 270)
Energy prices, Gas at approx. €0.12/kWh, a good heat pump at only €0.086/kWh (at JAZ 3.5)
Annual performance factor (JAZ), the higher, the less electricity you need for the same heat
The better these three fit together, the faster the system is "paid off". And in 2026, the cards are especially well stacked.
Here's a realistic example for a normal single-family home (150 m², well insulated, JAZ 3.5):
| Scenario | Net Costs After Funding | Annual Savings | Payback Period |
|---|---|---|---|
| Without funding | €25,000 | €1,543 | 16.2 years |
| With 50% KfW | €12,500 | €1,543 | 8.1 years |
| With 70% KfW | €7,500 | €1,543 | 4.9 years |
Conclusion of the case study: With the full 70% package (basis + replacement + efficiency bonus), you get your investment back in just under 5 years. After that, you save over €1,500 every year, and that for 15–20 years. It's like a well-interested investment, only you stay warm in the process.
Free calculator, no registration, instantly see how quickly it pays off for you
Open free calculator now →Apply for maximum 70% funding, Make sure to grab the replacement bonus (gas/oil exchange) and efficiency bonus (JAZ ≥ 4.0). This saves you €10,000–17,500 immediately.
Aim for JAZ ≥ 4.0, Modern air-water heat pumps achieve this easily nowadays. The 20% bonus pays off doubly: more funding + lower electricity costs.
Combine with PV system on the roof, With your own solar power, the effective electricity price for the heat pump often drops below €0.10/kWh. Amortization then shortens by another 1–2 years, and you become almost independent of electricity price fluctuations.
Bonus tip: Combine the heat pump with some additional insulation. This increases JAZ and makes funding even more attractive.
A short checklist before filing the application makes sure that 30% does not suddenly stay 30% when 50% or 70% would have been possible. The base bonus of 30% is yours for every new heat pump. The replacement bonus of 20% is added when you replace an old gas or oil heating system. And the efficiency bonus of 20% applies when your model reaches a JAZ of at least 4.0.
The whole thing is capped at 70% total funding and 21,000 EUR grant on 30,000 EUR of eligible costs. If you take all three bonuses, the net cost of a 25,000 EUR system drops from 25,000 EUR to 7,500 EUR. That is exactly the difference between an amortization in 16 years and one in under 5 years.
❓ How realistic is the €1,543 savings per year?
Very realistic at current gas prices of €0.12/kWh and a good heat pump. Many households are even higher, especially if the old heating was already older.
❓ Does living area strongly influence amortization?
Yes. The larger the house, the higher the annual savings, but amortization stays similar since the investment rises proportionally.
❓ What happens if energy prices rise?
Then the heat pump pays off even faster. Especially with rising CO₂ tax, gas becomes more expensive, your heat pump benefits from that.
❓ Does the heat pump pay off even without funding?
Yes, but only after 12–16 years. With the current KfW 270 funding, "someday" becomes "in under 5 years".