Heat pump or gas boiler: the figures side by side
Your gas boiler is nearing the end of its life. Replace it like for like or switch to a heat pump? Here is the gap in bills and outlay, with current figures.
A new gas boiler turns at best about 86 % of the gas’s energy into heat, the minimum set by the EU ecodesign regulation; an air-to-water heat pump produces on average 2.9 kWh of heat per kWh of electricity, according to ADEME’s measurements. Electricity costs €0.1985 per kWh at the regulated tariff, gas €0.1347 on average according to Eurostat. Per kWh of heat produced, gas comes to €0.1566 and the heat pump to €0.0684. The heat pump is therefore cheaper to run, all the more so in a cold climate, and lets you cancel the gas subscription. But it costs more to buy: the heat pump gets 5.5 % VAT, MaPrimeRénov’ and the CEE bonus with Coup de pouce, while a gas boiler pays 20 % VAT and is not funded by MaPrimeRénov’. The choice comes down to the gap between the two outlays, compared with the yearly saving.
Heat pump or gas boiler: the bill for each
Yearly gap in favour of the heat pump
€769
| New gas boiler (86%) | €1,365 |
| Air-to-water heat pump (SCOP 2.9) | €597 |
| Heat needed | 8,717 kWh |
Estimate: need worked out with the site’s insulation coefficient. Gas standing charge not counted: dropping it widens the gap.
Checked by Radif Partners · Editorial policy · Method and sources
The price per kWh of heat
| Equipment | Price per kWh bought | Price per kWh of heat |
|---|---|---|
| Gas boiler (86 % efficiency) | 0.1347 € | 0.1566 € |
| Oil boiler (86 % efficiency) | 0.1931 € | 0.2245 € |
| Electric heaters | 0.1985 € | 0.1985 € |
| Air-to-water heat pump (efficiency 2.9) | 0.1985 € | 0.0684 € |
| Ground-source heat pump (efficiency 4.1) | 0.1985 € | 0.0484 € |
A “kWh of heat” is the energy that actually reaches the rooms. It is the only unit that lets you compare equipment using different energies. The 86 % efficiency is the minimum EU Regulation 813/2013 has set for a new boiler since 2015; it favours the boiler, as an old boiler often does worse.
The yearly bill by climate
| Département | Gas boiler | Air-to-water | Yearly gap |
|---|---|---|---|
| Bouches-du-Rhône | €1,416 | €619 | €797 |
| Loire-Atlantique | €2,002 | €875 | €1,127 |
| Rhône | €2,127 | €930 | €1,198 |
| Bas-Rhin | €2,343 | €1,024 | €1,319 |
| Doubs | €2,489 | €1,088 | €1,401 |
Heat pump or gas boiler: the bill for each
Yearly gap in favour of the heat pump
€769
| New gas boiler (86%) | €1,365 |
| Air-to-water heat pump (SCOP 2.9) | €597 |
| Heat needed | 8,717 kWh |
Estimate: need worked out with the site’s insulation coefficient. Gas standing charge not counted: dropping it widens the gap.
The outlay
No open source publishes an average gas boiler price. For an air-to-water heat pump, the median of quotes published by the price observatory is €15,788, on a small sample. Grants cut it sharply: the CEE bonus with Coup de pouce (replacing a gas boiler qualifies), and MaPrimeRénov’ for blue, yellow and purple households. Get two quotes, one for a boiler and one for a heat pump, and enter the second in the calculator: it gives the out-of-pocket cost and payback.
What tips the balance
For the heat pump: a cold climate, a reasonably insulated house, low-temperature radiators or underfloor heating, high grants, a wish to drop the gas subscription. For the boiler: a very poorly insulated house with high-temperature radiators, a tight budget with no grant, a very mild climate where the saving is small. In that last case, insulating first is often the best investment.