Replacing an Oil Boiler with a Heat Pump in Luxembourg: Complete 2026 Guide
Still heating with oil? Now is the right time to switch to an air-water heat pump. In 2026, the Klimabonus Wunnen scheme covers up to €10,000 for an aerothermal heat pump replacing an oil boiler — and the 10-year age requirement has been removed. Here’s everything you need to know: compatibility, grants, costs, oil tank, steps, and real return on investment in Luxembourg.
Why replace your oil boiler now in Luxembourg?
Oil is the most expensive and most polluting heating fuel still in common use in Luxembourg. Since the 2021-2022 energy crisis, its price has risen by more than 50% compared to 2020, and remains highly volatile due to international oil markets and geopolitical tensions. By contrast, the electricity consumed by a heat pump can be generated from renewable sources, and its effective cost per thermal kWh produced is significantly lower.
For a typical Luxembourg household in a 120–150 m² home heated by oil, the annual heating bill often exceeds €2,500–4,000. With an air-water heat pump, the same home can drop to €1,200–2,000/year — saving around €1,500–2,000 every year.
There is also a regulatory and property dimension. The energy passport (CPE) of an oil-heated home is typically rated E, F or G. Switching to an air-water heat pump can gain two to three energy classes, directly increasing your property’s value and making it easier to sell or rent.
The requirement for your oil boiler to be at least 10 years old has been removed. You can now receive the replacement bonus even if your boiler is relatively new — a clear signal from the Luxembourg government to accelerate the phase-out of oil heating.
Is your home compatible with an air-water heat pump?
Good news for oil-heated Luxembourg homeowners: a home with an oil boiler and water radiators is almost always compatible with an air-water heat pump. In fact, this is the ideal use case for this type of heat pump.
Here’s the logic: your old oil boiler heated the circuit water to high temperatures (70–80°C). A modern air-water heat pump produces water at 35–55°C. The question is therefore not about replacing radiators, but verifying that your distribution network can operate at low temperature.
Compatibility criteria to check
Existing water radiators: if correctly sized (ideally oversized vs. the old boiler), they can operate at 45–55°C with the heat pump. Many Luxembourg radiators installed in the 1980s–2000s were deliberately oversized — making them perfectly compatible.
Existing underfloor heating: ideal, as it operates at low temperature (28–35°C) — perfectly suited to an air-water heat pump.
Old small cast iron radiators: if undersized and requiring 70°C+ to heat properly, replacement or supplementation may be needed. The 2026 Klimabonus includes a grant for adapting the distribution system.
Available outdoor space: the heat pump’s outdoor unit must be placed on a façade, in the garden or on the roof, respecting acoustic distances from neighbours.
Home insulation: good insulation improves heat pump efficiency. Even in an imperfectly insulated home (class C-D), an air-water heat pump is worthwhile — but a full renovation (insulation + heat pump) maximises grants and savings.
If in doubt about radiator compatibility, a qualified installer can perform a heat loss calculation (EN 12831 standard) to determine the exact heat pump power needed and verify whether existing radiators are sufficient. This step is included in any serious quote.
Check your home’s compatibility — get a free analysis from a certified installer.
Request a free quote →What to do with the oil tank during replacement?
This is a question every homeowner asks, and often a source of concern. Rest assured: tank management is a well-regulated process in Luxembourg, and it even benefits from specific financial assistance.
Options for your oil tank
Draining, degassing and in-situ neutralisation
The most common solution for buried tanks that are difficult to extract. An approved specialist drains residual oil, cleans and degasses the tank, then neutralises it by filling with sand or expanding foam. The tank remains in place but presents no further environmental or fire risk.
Full removal
For above-ground or accessible tanks, physical removal is possible. A specialist cuts the tank and takes it to an approved treatment centre. Estimated cost in Luxembourg: €800–2,000 depending on size and accessibility.
Conversion to rainwater cistern
In some cases, a tank in good condition can be reconditioned to store rainwater. This option is more complex and depends on the location and condition of the tank.
Grants for tank removal
The Luxembourg Klimabonus provides specific assistance for the removal, neutralisation and recycling of the oil tank. The 2026 scheme also introduced an additional bonus for tanks located in drinking water protection zones.
Additionally, Enoprimes provide additional support of up to €2,000 specifically for oil tank removal, cumulable with the Klimabonus.
Neutralisation or removal of an oil tank must be carried out by a licensed, specialist firm. Never attempt to drain or cut a tank yourself — hydrocarbon residues are flammable and toxic. Your heat pump installer can usually coordinate this work with a specialist.
2026 grants for replacing an oil boiler with a heat pump
This is one of the best-subsidised projects in Luxembourg. Three grants can be combined, plus possible municipal grants.
1. Klimabonus Wunnen 2026 — up to ~€10,000
The Klimabonus is Luxembourg’s main state grant for renewable technical installations. Since 1 January 2026, the scheme has been restructured with flat-rate amounts independent of installation power. For replacing an oil boiler with an air-water heat pump, the 2026 Klimabonus can reach approximately €9,000–10,000, including: the base grant for installing the heat pump; the fossil boiler replacement bonus (now integrated into base amounts); a supplementary grant for adapting the distribution system; a grant for oil tank removal; and a specific bonus if the tank is in a water protection zone.
The old « Tripartite » bonus and the oil boiler replacement bonus (Masuttersatzprogramm) are now integrated into the base amounts of the 2026 Klimabonus. Always verify exact amounts at klima-agence.lu.
2. Enoprimes — €1,500 to €2,000+
Enoprimes are paid by your energy provider (Enovos or Creos) after commissioning. They include a grant for the air-water heat pump installation (~€1,500) plus up to €2,000 for oil tank removal. Cumulable with Klimabonus.
3. Reduced VAT at 3%
All renovation work in a home more than 2 years old benefits from 3% VAT instead of 17%. On a €20,000 installation, this represents a direct saving of approximately €2,800.
4. Municipal grants — up to €3,000
Many Luxembourg municipalities offer additional energy renovation grants of €1,500–3,000. Contact your local authority or ask your installer.
| Grant type | Organisation | Estimated amount | When to apply? |
|---|---|---|---|
| Klimabonus air-water heat pump | Luxembourg State / Klima-Agence | Up to ~€9,000–10,000 | Before work starts (agreement in principle) |
| Enoprimes heat pump | Enovos / Creos | ~€1,500 | After commissioning |
| Enoprimes oil tank | Enovos / Creos | Up to €2,000 | After tank removal |
| Reduced VAT 3% | On installer invoice | ~€2,800 (base €20,000) | Applied directly on invoice |
| Municipal grant | Your municipality | €1,500–3,000 | Varies by municipality |
Calculate your personalised grants with our free tools.
Request a free quote →Costs, savings and return on investment
| Home profile | Gross installation cost | Estimated total grants | Net cost after grants | Annual savings | Payback period |
|---|---|---|---|---|---|
| 80–100 m² house, compatible radiators | €16,000–19,000 | €11,000–13,500 | From ~€5,000 | €1,200–1,800 | 3–5 years |
| 100–150 m² house, radiator adaptation included | €18,000–24,000 | €12,000–15,000 | From ~€6,000 | €1,500–2,500 | 4–6 years |
| House > 150 m², high power required | €22,000–28,000 | €12,000–15,000 | From ~€10,000 | €2,000–3,500 | 4–6 years |
Grants include Klimabonus + Enoprimes + 3% VAT. Indicative data based on real Luxembourg projects — 2026.
Why are oil savings so significant?
Heating oil in Luxembourg costs approximately €0.90–1.20/litre with a calorific value of ~10 kWh/litre, giving an effective cost of 9–12 cents per thermal kWh (at 85–90% boiler efficiency). A heat pump with a COP of 3.5 and electricity at €0.25/kWh costs just 7 cents per thermal kWh — 25–35% cheaper than oil.
A 130 m² oil-heated home typically consumes 2,500 litres of fuel per year, costing ~€2,600 (at €1.05/litre). With an air-water heat pump (average COP 3.2), the same home needs ~8,000 kWh of electricity, costing ~€2,000 — saving at least €600/year, and significantly more during oil price peaks.
Project steps: from decision to grants received
Simulation and budget estimate
Start by simulating your grants and project budget using the Klima-Agence simulator.
Visit and free quote from a certified installer
Have a free quote drawn up by a professional certified and registered with the Luxembourg Chamber of Crafts. The installer will conduct a thermal study of the building (EN 12831 standard). Compare at least 2 quotes — the difference can reach €3,000–5,000 for the same installation.
Energy advice and Klimabonus agreement in principle
A request for agreement in principle must be submitted to the AEV environmental agency before work begins, via MyGuichet.lu. Your installer can handle this administrative process.
Heat pump installation (2–4 days)
Once agreement in principle is obtained, work can begin. An air-water heat pump installation typically takes 2–4 days. In parallel, the oil tank removal is scheduled with a specialist.
Acceptance and grant applications
After installation, the installer must submit an acceptance request to the Chamber of Crafts building inspection service within one month of commissioning. You can then submit your Klimabonus and Enoprimes grant applications.
Grant payment
Allow approximately 2–4 months for Klimabonus payment after submitting a complete file. Enoprimes are generally processed faster by your energy provider.
What do the replacement works involve?
Day 1 — Boiler removal and preparation: The team takes the heating system out of service, drains the water circuit, and removes the old oil boiler. The burner, tank, pump and connection pipes are dismantled.
Days 1-2 — Outdoor unit installation: The outdoor unit is positioned and secured according to acoustic and maintenance constraints. Core holes are drilled in the façade to run refrigerant and electrical connections between the outdoor and indoor units.
Days 2-3 — Indoor unit and hydraulics: The indoor unit is installed where the old boiler was. The buffer tank (minimum 30 litres per kW of power in existing buildings, per 2026 Klimabonus rules), domestic hot water tank, pump and all hydraulic connections are installed. Hydraulic balancing of the heating network is performed — a mandatory condition for Klimabonus eligibility.
Days 3-4 — Testing, commissioning and adjustment: The heat pump is commissioned. Installers test pressures, verify there are no refrigerant leaks (F-Gas compliant), adjust heating curves and complete a full heating cycle. You receive training on using the controls.
Since the 2022 scheme and confirmed in 2026, the heat pump must be fitted with a heat meter and a dedicated electricity meter. These instruments track the real-world COP of your installation — and are required for the Klimabonus application.
Special cases: old house, large area, harsh winters
Houses built before 1980: insulate first?
A common question. Our experts’ nuanced answer: not mandatory, but strongly recommended to do both simultaneously. An air-water heat pump can work perfectly in a poorly insulated home — it will simply be more powerful and consume more electricity. Combining insulation and heat pump in the same project enables additional Klimabonus grants and allows for a smaller, less expensive heat pump. The cumulative saving over 15 years can exceed €15,000.
Large homes (> 130–150 m²)
For very large homes, a single air-water heat pump may be insufficient during prolonged cold snaps. Recommended solutions: high-power air-water heat pump (12–16 kW) with integrated backup resistance; hybrid heat pump + wood pellet boiler (heat pump covers 70–90% of annual needs); or geothermal heat pump for best year-round performance.
Very low temperatures: real behaviour in Luxembourg
Luxembourg experiences cold winters with temperatures regularly falling to −5°C to −10°C. At these temperatures, an air-water heat pump’s COP drops to 1.5–2.5. However, periods below −10°C account for less than 5% of annual heating hours in Luxembourg. Over the full season, the average COP is generally 2.8–3.5 — highly cost-effective overall.
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Request free quotes →Frequently asked questions — Replacing an oil boiler with a heat pump in Luxembourg
Can I replace a recent oil boiler (less than 10 years old) and still receive the Klimabonus?
Yes, since 1 January 2026. The new Klimabonus Wunnen 2026 scheme has removed the condition requiring the boiler to be at least 10 years old. Regardless of your oil boiler’s age, you can claim the full grant if your heat pump installation meets the required technical conditions.
Are my radiators compatible with an air-water heat pump?
In the vast majority of Luxembourg cases, yes. Homes with oil boilers and water radiators are generally compatible with an air-water heat pump. A certified installer will perform a heat loss calculation during the visit to confirm compatibility. If some radiators need adapting, the Klimabonus includes a specific grant for this adaptation.
What happens to my oil tank? Must I have it removed?
Luxembourg law does not require immediate removal if the tank is in good condition. However, it is strongly recommended to neutralise or remove the tank when replacing the boiler. The Klimabonus and Enoprimes include specific grants for tank removal. In-situ neutralisation costs €500–1,500 and is the most common solution for buried tanks.
How much does replacing an oil boiler with an air-water heat pump cost after grants?
For a 100–150 m² home, expect a gross cost of €18,000–24,000. After Klimabonus, Enoprimes and 3% VAT, the remaining cost is typically €6,000–10,000. Payback is generally 4–6 years, thanks to annual heating savings of €1,500–2,500.
Does my air-water heat pump also produce domestic hot water?
Yes. Most air-water heat pumps installed in Luxembourg integrate domestic hot water production via a coupled thermodynamic tank. The heat pump thus provides both heating and hot water with a single system.
What maintenance does a heat pump require?
An air-water heat pump has an average lifespan of 15–20 years with proper maintenance. An annual maintenance contract is strongly recommended: checking the refrigerant circuit, cleaning filters and the outdoor unit heat exchanger, verifying electrical connections. An annual contract in Luxembourg typically costs €150–300.
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