Your old boiler has just died in the middle of winter, and three quotes are waiting: a heat pump at €15,000, a condensing boiler at €5,000, a connection to the neighbourhood heat network at €8,000. Which one to choose? The answer is not on the first line of the quote. Over the equipment's lifetime — around fifteen years — it is the total cost of ownership that decides: installation, annual consumption, maintenance, grants deducted. And it often holds surprises.
The classic trap is to reason on the purchase price. Yet over fifteen years, the heating-bill gap between two solutions can far exceed the difference in installation price. On top of that sits a parameter many overlook: your heating system weighs not only on your bill, but also on your EPC label (the French DPE, Diagnostic de Performance Énergétique — Energy Performance Certificate) — and the two do not always move in the same direction.
Up to 75% heating savings reported by France's environment agency ADEME for a heat pump replacing electric convectors, and around 15% to 30% for a condensing boiler replacing a conventional one: the consumption gap, compounded over 15 years, becomes the decisive item of the total cost.
What this article covers
The three central-heating solutions compared item by item — installation, consumption, maintenance, lifespan, 2026 grants —, the total-cost-of-ownership method over 15 years, the decisive effect of the primary-energy conversion coefficient (1.9 for electricity since 2026) on the EPC label, the case of gas facing its progressive ban in new builds, and the mistakes that distort a quote comparison.
Three heating solutions, three cost logics
Three solutions now compete to replace a central heating system: the air-to-water heat pump, the condensing gas boiler and connection to an urban heat network (the French RCU). Each follows a distinct economic logic, which you must understand before comparing quotes.
The air-to-water heat pump is a thermodynamic machine that captures calories from outside air to heat the water in the heating circuit. Its strength is efficiency: for 1 kWh of electricity consumed, it delivers several kilowatt-hours of heat. This ratio, the coefficient of performance (COP), is in practice between 3 and 4 depending on the model and climate. Its downside is a high installation price.
The condensing gas boiler recovers the latent heat of combustion fumes, giving it a higher efficiency than a conventional boiler (around 90% and above on lower heating value). It remains the cheapest equipment to install and the natural continuity solution for a home already connected to mains gas. But it burns a fossil fuel, which weighs on greenhouse-gas (GHG) emissions — and therefore on the EPC.
The urban heat network is a centralised boiler plant distributing heat to a set of buildings through a pipe network. The home no longer has an individual boiler: it has a simple exchange sub-station. Connection is only possible if a network runs nearby — it is therefore a geographic option before being a technical choice. According to SDES, France had over 900 heat networks, supplied more than 60% by renewable and recovered energy.
These three logics explain why an honest comparison cannot stop at the headline price. A heat pump that is expensive to buy can become the cheapest over time; a heat network that is cheap to install can disappoint if the local heat tariff is high. The only reliable arbiter is the total cost of ownership.
Installation, consumption, maintenance: cost item by item
To compare the three solutions, you must break cost down into four items: installation (a one-off cost), annual consumption (the item that compounds), maintenance (recurring and regulated) and lifespan (which determines over how many years to amortise the installation). The ranges below are ADEME and France Rénov' orders of magnitude, to refine with real quotes.
Installation: a one-off cost with wide variation
The installation item clearly separates the three solutions. As an illustration, ADEME puts an air-to-water heat pump between €10,000 and €18,000 fitted, a condensing gas boiler between €3,000 and €6,000, and a heat-network connection around €5,000 to €10,000 depending on the building configuration and distance to the network. These amounts vary strongly with the heated area, the power required and the complexity of the works (creating a water circuit, adapting the emitters).
| Item | Air-to-water heat pump | Condensing gas boiler | Heat network (RCU) |
|---|---|---|---|
| Installation (indicative) | €10,000 to €18,000 | €3,000 to €6,000 | €5,000 to €10,000 |
| Energy consumed | Electricity (COP 3-4) | Natural gas | Network heat (local mix) |
| Maintenance | Every 2 years (mandatory) | Annual (mandatory) | Reduced (no boiler) |
| Indicative lifespan | 15 to 20 years | 15 to 20 years | Very long (network) |
Indicative ADEME / France Rénov' ranges, before grants; the real cost depends on the home, the power and local energy prices.
Consumption: the item that compounds
This is where most of the 15-year outcome plays out. The heat pump consumes electricity, but in reduced quantity thanks to its efficiency: ADEME indicates a heat pump can divide heating energy consumption by three to four compared with electric convectors. Against a gas boiler, the comparison depends on the relative price of the electricity and gas kilowatt-hour, which varies over time. The condensing boiler reduces gas consumption by around 15% to 30% versus an old boiler, without changing fuel. The heat network bills the heat delivered at a local tariff combining a fixed part (subscription) and a variable part: its cost per kWh is regulated but heterogeneous from one network to another.
Profile: a 100 sqm detached house previously heated by oil or an old gas boiler, an owner-occupier wanting both to cut the bill and to escape an F or E label — this is the case where the air-to-water heat pump most often delivers the best total cost.
Maintenance and lifespan: real differences
Maintenance is regulated and recurring. The gas boiler requires mandatory annual maintenance (decree no. 2009-649 of 9 June 2009). A heat pump over 4 kW is subject to periodic maintenance at least every two years (decree no. 2020-912 of 28 July 2020). Connecting to a heat network removes the maintenance of an individual boiler: the network operator manages production, which cuts the home's charges accordingly. On lifespan, heat pump and boiler amortise over around fifteen years; the network is a very long-lived collective asset.
The total cost over 15 years: the only comparison that counts
Total cost of ownership adds up, over the equipment's lifetime, the installation cost (net of grants), the annual consumption multiplied by the number of years, and the cumulative maintenance. It is this sum — not the quote price — that should guide the decision. Over 15 years, the consumption item generally becomes the heaviest: it is what often reverses the ranking based on purchase price alone.
Take a deliberately simplified illustration, indicative only. For a house whose heating cost €2,000 a year with an old boiler, an air-to-water heat pump halving that bill would save around €1,000 a year, or roughly €15,000 over 15 years — an amount comparable to the installation premium. The same house switched to a condensing boiler would save less per year but would have cost much less to install. These orders of magnitude only serve to set ideas: your case depends on the climate, the insulation and energy prices, which are inherently moving.
Scenario — 100 sqm house, initial heating €2,000/year (illustrative)
| Item over 15 years | Heat pump | Condensing boiler | Heat network |
|---|---|---|---|
| Installation net of grants (indicative) | ~€8,000 to €13,000 | ~€3,000 to €5,000 | ~€4,000 to €8,000 |
| Cumulative consumption (illustrative) | the lowest | intermediate | varies by local tariff |
| Cumulative maintenance (indicative) | ~€1,500 to €3,000 | ~€2,000 to €3,000 | reduced |
| Dominant logic | The consumption item, compounded over 15 years, separates the solutions — not the headline purchase price. | ||
The reading is clear: a solution expensive to install but frugal in use can beat a cheap but energy-hungry one, once you reason over time. To estimate these items with your home's real characteristics rather than with ranges, the dedicated tool computes the gain per scenario: see the OneDpe renovation works simulator.
Real bill or EPC label: don't confuse the two
Here is the point most comparisons neglect: the heating system acts on two distinct planes at once — your real bill and your EPC label — and the two do not react the same way. Confusing them leads to backwards decisions.
Why electricity is favoured on the energy label
The EPC does not measure your bill: it computes a conventional consumption in primary energy. Final energy (the one passing through the meter) is multiplied by a conversion coefficient specific to each fuel to obtain primary energy, which sets the label. The (ministerial) order of 13 August 2025 (published in the Official Journal on 26 August 2025) lowered the electricity coefficient from 2.3 to 1.9 from 1 January 2026, amending the order of 31 March 2021 (amended on 25 March 2024) that sets the 3CL-DPE method. Gas and oil stay at 1.0.
The consequence: a heat pump, because it consumes little electricity (thanks to its COP) and that electricity is now converted at 1.9, comes out very favourably on the energy label. Conversely, a gas boiler, however efficient, is penalised on the climate label (GHG emissions), because burning gas emits CO2. Since the EPC label kept is the worse of the two scales (energy and climate), a gas-heated home often caps its class because of the climate scale. To understand why electricity comes out so favourably on the energy label, our dedicated analysis details the effect of the electricity coefficient lowered to 1.9 on the EPC.
⚠️ Warning: a better EPC label does not automatically mean a lower bill, and vice versa. The EPC is a conventional primary-energy calculation; your bill depends on real kilowatt-hour prices and your actual consumption. Decide by looking at both planes, never just one.
The regulatory stake: escaping thermal-sieve status
The label is not just a symbol: it conditions the right to let. The timetable from Act no. 2021-1104 of 22 August 2021 (the Climate & Resilience Act), codified in articles L.173-1-1 and L.173-2 of the Construction and Housing Code (CCH), bans letting homes rated G since 2025, F from 2028 and E from 2034. A change of heating that gains a class can therefore lift a home out of the ban — a direct asset stake for a landlord. This is precisely one of the levers to weigh in the 5 best-ROI works to gain a grade on the EPC.
2026 grants and the case of gas
MaPrimeRénov' and heating-change grants
Replacing a heating system with a high-performance solution is supported by several stackable schemes, subject to conditions. MaPrimeRénov' (French national energy renovation grant), run by the National Housing Agency (Anah), funds notably the installation of a heat pump and connection to a heat network, with amounts scaled to household income. For 2026, the scheme reopened on 23 February 2026, an appointment with a France Rénov' adviser is required for the guided pathway, and internal insulation (ITI) as well as external insulation (ITE) are excluded from the single-action pathway. Added to this are Energy Saving Certificates (CEE) paid by energy suppliers, and the zero-rate eco-loan (eco-PTZ) to finance the remaining cost. Gas-fired boilers are no longer eligible for MaPrimeRénov' since 2023.
What to check before any quote: your taxable income (MaPrimeRénov' colour band), the presence of a heat network nearby, the installer's eligibility (RGE certification, required for most grants), and how the stackable grants combine (MaPrimeRénov' + CEE + eco-PTZ) — it is the net grant that determines the real installation cost.
Gas and the progressive ban in new builds
Gas is retreating in new construction. The 2020 environmental regulation (RE2020), in force since 1 January 2022, sets a greenhouse-gas emissions cap that effectively excludes gas heating from new homes: since 2022 for detached houses, and with the scheme extended to multi-unit housing. For new builds, the heat pump and connection to a heat network have become the reference solutions. In existing homes, however, replacing a gas boiler with a condensing boiler remains allowed: no general installation ban hits gas in older housing to date. The regulatory trajectory nonetheless encourages anticipating the progressive exit from fossil fuels.
The mistakes that distort a quote comparison
Mistake 1 — Comparing on installation price alone
This is the cardinal error. Choosing the cheapest solution to fit, without factoring in 15 years of consumption, regularly leads to the wrong trade-off. A gap of a few hundred euros in annual bill turns, compounded over the equipment's lifetime, into several thousand euros that can exceed the initial price difference. Always reason in total cost of ownership.
Mistake 2 — Confusing a lower bill with a higher EPC label
A heat pump can markedly improve your EPC label without dividing your bill by as much — and an efficient gas boiler can lower the bill a little without moving the climate label. Do not decide by looking at a single indicator: your goal (re-letting a property, cutting a bill, adding resale value) determines which of the two planes prevails.
Mistake 3 — Overestimating the COP of a poorly sized heat pump
The coefficient of performance shown in the lab is not the real seasonal efficiency. An oversized, badly tuned heat pump, or one installed in a poorly insulated home, will see its seasonal efficiency fall, especially in hard frost. Hence the rule: insulate first, then size the heat pump on the reduced needs. This is the whole point of the order of energy renovation works, which places insulation before the change of system.
⚠️ Warning: installing a heat pump in an uninsulated thermal sieve means sizing a large machine on excessive needs and degrading its real efficiency. The expected gain melts away, and the bill stays high. Insulation conditions the performance of the new heating.
Mistake 4 — Forgetting the local heat-network tariff
The heat network appeals through its low installation cost and the absence of a boiler to maintain, but its running cost depends entirely on the local network tariff — highly variable from one city to another. Before signing a connection, ask for the tariff schedule (fixed and variable parts) and the network's renewable-energy share, which also conditions its EPC effect and the applicable VAT rate.
Estimate the total cost of your heating change
OneDpe renovation works simulator
Compare heating scenarios on your home's real data: the simulator estimates the EPC class gain, the consumption drop and the works cost for a heat pump, an efficient boiler or a connection, factors in grants (MaPrimeRénov', CEE, eco-PTZ) and quantifies the return on investment year by year. The calculation relies on the 3CL engine developed in-house by OneDpe, faithful to the method of the order of 31 March 2021.
To go further: the 5 best-ROI works to gain a grade on the EPC.
Conclusion
Between a heat pump, a condensing boiler and a heat network, there is no universal winner: the right choice depends on the home's insulation, the fuel already in place, the presence of a network and the goal pursued. One rule stays constant: it is the total cost over 15 years — installation net of grants, cumulative consumption, maintenance — that decides, never the quote price alone. And you must read both planes in parallel: the real bill on one side, the EPC label on the other, which the electricity coefficient lowered to 1.9 now tilts in favour of efficient electric solutions.
The useful reflex: quantify each scenario with your property's characteristics before signing. The OneDpe renovation works simulator compares heating solutions, factors in 2026 grants and computes both the EPC gain and the return on investment — turning three quotes into a grounded decision.
