Heat Pump vs Gas Boiler: Which Heating System Is Best?
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Heat Pump (Air Source) vs Gas Boiler (Condensing)
| Criterion | Heat Pump (Air Source) | Gas Boiler (Condensing) |
|---|---|---|
| Installation cost | EUR 7,000-16,000 | EUR 2,000-4,000 |
| Annual running cost (100 sqm home) | EUR 1,100-1,400 | EUR 900-1,200 |
| Lifespan | 15-20 years | 10-15 years |
| Annual maintenance cost | EUR 100-200 | EUR 80-120 |
| CO2 emissions (annual) | 1,200-1,800 kg | 3,500-5,000 kg |
| Noise level | 40-55 dB (outdoor unit) | Silent (indoor unit) |
| Space required | Outdoor unit + indoor cylinder | Wall-mounted boiler |
| Installation time | 3-5 days | 1-2 days |
| Government grants available | EUR 3,500-7,500 | None |
| Resale value impact | +3-5% home value | Neutral |
Installation cost
Heat Pump (Air Source)
EUR 7,000-16,000
Gas Boiler (Condensing)
EUR 2,000-4,000
Annual running cost (100 sqm home)
Heat Pump (Air Source)
EUR 1,100-1,400
Gas Boiler (Condensing)
EUR 900-1,200
Lifespan
Heat Pump (Air Source)
15-20 years
Gas Boiler (Condensing)
10-15 years
Annual maintenance cost
Heat Pump (Air Source)
EUR 100-200
Gas Boiler (Condensing)
EUR 80-120
CO2 emissions (annual)
Heat Pump (Air Source)
1,200-1,800 kg
Gas Boiler (Condensing)
3,500-5,000 kg
Noise level
Heat Pump (Air Source)
40-55 dB (outdoor unit)
Gas Boiler (Condensing)
Silent (indoor unit)
Space required
Heat Pump (Air Source)
Outdoor unit + indoor cylinder
Gas Boiler (Condensing)
Wall-mounted boiler
Installation time
Heat Pump (Air Source)
3-5 days
Gas Boiler (Condensing)
1-2 days
Government grants available
Heat Pump (Air Source)
EUR 3,500-7,500
Gas Boiler (Condensing)
None
Resale value impact
Heat Pump (Air Source)
+3-5% home value
Gas Boiler (Condensing)
Neutral
Heat Pump vs Gas Boiler: A Detailed Comparison
The decision between a heat pump and a gas boiler affects your heating bills, carbon footprint, and home value for the next 15-20 years. This guide compares both systems on every metric that matters so you can make an informed choice.
How They Work
A gas boiler burns natural gas to heat water, which is circulated through radiators or underfloor heating. Modern condensing boilers recover heat from exhaust gases, achieving 90-95% efficiency. For every kWh of gas burned, you get 0.90-0.95 kWh of heat.
A heat pump extracts heat from outdoor air (or the ground) and concentrates it to heat water. It uses electricity to drive a compressor, but delivers 2.5-4 times more heat energy than the electrical energy it consumes. For every kWh of electricity used, you get 2.5-4 kWh of heat.
Cost Comparison Over 15 Years
| Cost Item | Heat Pump | Gas Boiler |
|---|---|---|
| Installation | EUR 11,000 | EUR 3,000 |
| Grant deduction | -EUR 5,000 | EUR 0 |
| Net installation cost | EUR 6,000 | EUR 3,000 |
| Annual running cost | EUR 1,225 | EUR 1,010 |
| Annual maintenance | EUR 150 | EUR 100 |
| Replacement at year 12-15 | EUR 0 | EUR 3,000 |
| 15-year total | EUR 26,625 | EUR 19,650 |
Based on 100 sqm home, 14,000 kWh annual heating demand. Gas boiler needs replacement at year 12.
With current energy prices and grants, a gas boiler is still cheaper over 15 years for homes already connected to the gas grid. However, if gas prices rise by 5% annually (as many forecasts predict), the heat pump becomes cheaper from year 10 onwards. Use our heat pump calculator to see the comparison for your specific home.
Environmental Comparison
| Metric | Heat Pump | Gas Boiler |
|---|---|---|
| CO2 per kWh of heat | 0.070-0.095 kg | 0.215-0.240 kg |
| Annual CO2 (14,000 kWh demand) | 1,300-1,700 kg | 3,350-3,750 kg |
| CO2 reduction vs gas | 55-65% | Baseline |
| Lifetime CO2 (20 years) | 26-34 tonnes | 67-75 tonnes |
A heat pump cuts CO2 emissions by over half compared to a gas boiler. As electricity grids become greener (more wind and solar), the heat pump's carbon footprint will decrease further. Gas emissions remain constant. Countries like France (80% nuclear electricity) see even larger CO2 reductions from heat pumps.
Which Homes Suit Each System?
Heat pump is ideal for: Well-insulated homes (post-2000 or retrofitted), homes with underfloor heating, properties replacing oil or LPG (biggest savings), new builds, and homes with solar panels. Check your insulation level before deciding.
Gas boiler is better for: Homes needing urgent replacement on a tight budget, very poorly insulated homes where heat pump sizing becomes impractical, homes without space for an outdoor unit, and properties in conservation areas where planning permission may be difficult.
The Hybrid Option
A hybrid system combines a heat pump with a gas boiler backup. The heat pump runs most of the time (handling 80-90% of heating hours), and the gas boiler kicks in only during the coldest days. This approach reduces the required heat pump size, lowers installation cost, and still cuts CO2 by 50-60%. Hybrids are a practical stepping stone for homes that are not yet ready for a full heat pump installation.
These calculations are estimates only. Actual requirements may vary depending on surface conditions, product specifications, and installation methods. Always consult a qualified professional for precise measurements.
Prices updated: 2026-03Frequently Asked Questions
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