Comparison · 7 min read · Updated 2026-05-07
Heat pump vs gas boiler — payback, CO₂ and what changes in 2027
Apples-to-apples economic and environmental comparison. The break-even depends entirely on the electricity-to-gas price ratio and your subsidy access.
The economic question
A condensing gas boiler delivers about 0.92 kWh of heat per kWh of gas burned. A modern heat pump delivers 4.0+ kWh of heat per kWh of electricity. So every kWh of heat costs you:
- Gas: gas_price / 0.92
- HP: electricity_price / SCOP
The break-even electricity-to-gas price ratio is SCOP × 0.92. For SCOP = 4: HP wins as long as electricity is less than 3.7× the price of gas per kWh.
Plug in current Eurostat household tariffs (semester 2024-S2):
| Country | Gas €/kWh | Elec €/kWh | Ratio | HP wins? |
|---|---|---|---|---|
| France | 0.117 | 0.247 | 2.1× | ✅ yes |
| Italy | 0.148 | 0.297 | 2.0× | ✅ yes |
| Poland | 0.063 | 0.167 | 2.7× | ✅ yes |
| Germany | 0.122 | 0.387 | 3.2× | 🟡 marginal at SCOP 4 |
| Belgium | 0.090 | 0.350 | 3.9× | ❌ losing at SCOP 4 |
Germany is the famously hard market — high electricity makes the math tight. Two ways to flip it:
1. Higher SCOP — modern ground-source units hit SCOP 5+, breaking even with electricity at 4.6× gas. 2. Time-of-use tariffs — heat pump on cheap night-rate electricity (often 50–70% of day rate). Many German utilities offer this (Wärmepumpen-Tarif).
Capex and break-even years
Take a 150 m², 18 000 kWh-heat home in Germany:
| Gas boiler | Air-water HP | |
|---|---|---|
| Capex installed | €8 000 | €18 000 |
| BEG subsidy | — | €−12 600 (70%) |
| Net capex | €8 000 | €5 400 |
| Annual cost | €2 393 | €1 741 |
| Annual saving | — | €652 |
| Payback | — | −4 years (HP cheaper from day one) |
The German subsidy is so generous in 2026 that an income-qualified household pays less upfront for a heat pump than a gas boiler. This is the exact policy lever the BEG is engineering.
CO₂ comparison
Gas burned for heating emits about 200 g CO₂eq/kWh of fuel input. Electricity emissions depend on your country's grid mix:
| Country | Grid g CO₂/kWh | Gas (200 g/kWh × 1/0.92) | HP (grid × 1/4.0) |
|---|---|---|---|
| France | 60 | 217 | 15 |
| Sweden | 35 | 217 | 9 |
| Spain | 200 | 217 | 50 |
| Germany | 366 | 217 | 92 |
| Poland | 615 | 217 | 154 |
A heat pump beats gas on CO₂ in every EU country once SCOP > 2.5. The gap is largest where the grid is cleanest (FR, SE, NO).
What changes 2027–2030
- Gas prices: ETS-2 carbon price hits residential heating 2027 →
expect +€0.03–0.05/kWh on gas bills.
- Refrigerants: GWP > 150 banned in new ≤12 kW HPs from 2027
(R32 must drop, R290 dominant).
- DE phase-out: from 2024, 65% renewable share required for new
heating systems → essentially mandatory HP for new build / boiler replacement.
The trend is clear: gas gets more expensive, HPs get cheaper, subsidies move accordingly. Anyone replacing a heater after 2025 should price the HP scenario as the default, not the upgrade.
Use our payback calculator to plug in your own numbers.