Replacing a Gas Boiler with a Heat Pump in Luxembourg: Complete 2026 Guide
Do you heat with natural gas and wonder whether switching to a heat pump really makes sense? In Luxembourg, around 50,000 customers are connected to the Creos natural gas network — many in well-served urban and suburban areas. Yet, given gas price volatility since 2022, the increasingly generous 2026 Klimabonus grants, and a new CO₂ tax on fossil fuels, the case for heat pumps is stronger than ever. This guide explains whether replacement makes sense for your situation, what it involves technically — including the management of your gas subscription, a specificity unique to this situation — and how to maximise the available grants.
Natural gas vs heat pump: is it really worth switching in Luxembourg?
This is the central question, and the answer deserves nuance. Unlike oil boilers — which have structurally high fuel costs — recent condensing gas boilers are already efficient appliances, with efficiency of around 105–110%. The profitability calculation for switching to a heat pump therefore depends on several variables specific to the Luxembourg context in 2026.
The gas/electricity price ratio in Luxembourg 2026: the key factor
In 2026, natural gas in Luxembourg costs approximately €0.10–0.13/kWh all-inclusive (energy + Creos network usage + levies + CO₂ tax + 8% VAT). To heat a 130 m² home, a condensing boiler typically consumes 15,000–20,000 kWh of gas per year, giving a bill of €1,500–2,600.
Electricity costs approximately €0.25/kWh in Luxembourg. But an air-water heat pump with a seasonal average COP of 3.2 consumes 1 kWh of electricity to produce 3.2 kWh of heat — an effective thermal cost of approximately €0.078/thermal kWh, lower than gas.
The price ratio is therefore broadly favourable to the heat pump, with annual savings of around 20–40% on the heating bill — less spectacular than switching from oil (where savings often exceed 45%), but very significant over a 15–20 year installation lifetime.
Luxembourg has introduced a progressive carbon tax on fossil fuels. This already weighs on the price of natural gas and will continue to increase. Over a 10-year horizon, the cost differential between gas and heat pump electricity should widen further in favour of the heat pump.
When replacement is clearly recommended
Your gas boiler is more than 15 years old
The ideal moment to skip replacing with a new (unsubsidised) gas boiler and go straight to a heat pump benefiting from the 2026 Klimabonus.
You’re planning a full renovation
Combining heat pump and renovation (insulation, windows, ventilation) maximises both operating savings and cumulative Klimabonus grants.
Your home is energy class D or better
The heat pump will be fully efficient and gain one to two additional energy classes, adding property value.
You’re considering solar panels
The heat pump + solar combination is particularly powerful in Luxembourg, with the heat pump programmed to preferentially consume daytime solar electricity via the buffer tank.
When the situation warrants reflection
Your condensing gas boiler is recent (less than 5 years old) and working perfectly
The investment is less obvious in the short term. However, the 2026 Klimabonus having removed the 10-year age condition, you are still eligible if you wish to plan ahead.
Your home is class F, G or H (very poorly insulated)
Improving insulation should be the priority so the heat pump is correctly sized. A high-temperature (HT) heat pump can be an intermediate solution.
You are a tenant
Boiler replacement is the landlord’s responsibility. As a landlord, however, energy renovation adds value and anticipates future regulatory requirements on energy classes for rental properties.
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Simulate my heat pump project → Free quote →Technical specifics of replacing a gas boiler with a heat pump
Technically, replacing a gas boiler with an air-water heat pump follows the same general pattern as replacing an oil boiler. But several technical points deserve special attention in the case of gas.
The existing heating circuit: an often-overlooked advantage of condensing gas
Modern condensing gas boilers (post-2000) already operate at low return temperatures — generally between 40 and 50°C — to maximise their condensation rate. This means that heat emitters in a home with a recent condensing boiler are often directly compatible with a standard air-water heat pump, without costly radiator adaptation.
If your gas boiler is old (pre-2000, high temperature of 70–80°C), radiator compatibility must be verified — exactly as for an old oil boiler. An installer performs a heating surface calculation during the site visit to confirm that existing radiators are sufficient at a lower flow temperature.
High-temperature (HT) heat pumps: the solution for poorly insulated homes
For homes that are still insufficiently insulated or with undersized radiators, high-temperature air-water heat pumps can produce water at 65°C or even 75°C (vs. 55°C max for a standard heat pump). Their COP is slightly lower (around 2.5–3.0), but they remain far more economical than a gas boiler.
High-temperature heat pumps are eligible for Klimabonus provided the chosen model meets the required COP thresholds (≥ 3.1 at A2/W35 regime for air-water heat pumps). Check with your installer that the model is listed on the eligible equipment list of the Environment Administration.
Domestic hot water production after replacement
When replacing with an air-water heat pump, options include: a DHW tank coupled to the main heat pump (most economical); an integrated DHW module (hydrokit); or an independent thermodynamic water heater as a supplement (eligible for separate Klimabonus grants).
Boiler room space: absolutely must be anticipated
A wall-mounted gas boiler (very common configuration in Luxembourg) is a compact appliance. Its replacement introduces an indoor unit + buffer tank + DHW tank — a significantly larger assembly. Available space in your technical room must be assessed during the installer’s visit. In homes without a basement or with a very small technical room, an experienced installer will propose alternative solutions (compact hydrokit, vertical buffer tank, basement installation).
Technical requirements for the 2026 Klimabonus
- Minimum COP ≥ 3.1 (air-water heat pump, A2/W35 regime) or ≥ 4.3 (geothermal, B0/W35)
- Buffer tank of minimum 30 l/kW of nominal thermal capacity (except modulating heat pumps)
- Heat meter and dedicated electricity meter for the heat pump, mandatory
- Hydraulic balancing of the heating network
- Acoustic limits: ≤ 48 dB(A) for heat pumps ≤ 5 kW, ≤ 51 dB(A) for 5–12 kW, ≤ 55 dB(A) for > 12 kW
- Acceptance request mandatory at the Chambre des métiers within one month of commissioning
What to do with your gas subscription and installation after replacement?
This is a question specific to switching from gas to a heat pump — it simply doesn’t exist for those who heated with oil. In Luxembourg, if you are connected to the Creos natural gas network and replace your boiler with a heat pump, you will need to manage two separate processes: cancellation of the gas supply contract, and closure of the delivery point with Creos.
Step 1: Cancel your gas supply contract
Contact your gas supplier (Enovos/LEO Energy, SUDénergie, or other active Luxembourg supplier) to cancel your contract. Under Luxembourg gas market regulation, cancellation of a residential natural gas supply contract is free of charge and without binding notice period. Your supplier will arrange a final meter reading and send a closing invoice.
If you wish to keep gas for other uses (e.g., a gas hob), you can keep the contract but change to a different tariff category, eliminating the heating portion.
Step 2: Close the delivery point with Creos
After cancelling the supply contract, closure and physical removal of the gas meter must be requested directly from Creos as the distribution network manager. Creos sends a technician to seal the connection and remove the meter. This service may be charged according to current Creos service tariffs.
Step 3: Decommissioning the internal gas installation
Internal gas pipes must be correctly sealed by a certified gas installer, in compliance with the Grand-Ducal regulation of 27 February 2010 on gas installations. A formal acceptance by the Chambre des métiers is mandatory to confirm the decommissioning.
Never attempt to seal a gas installation yourself. This must be carried out by a certified professional, with mandatory acceptance by the Chambre des métiers. Non-conformities found at acceptance can result in immediate decommissioning until remediation.
Timing and coordination
To avoid any heating interruption, plan the gas closure on the same day or within 24 hours of heat pump commissioning. Your heat pump installer can coordinate this timing. Experienced installers offer complete coordination services including gas supplier notification and Chambre des métiers acceptance for the gas decommissioning.
2026 grants for replacing a gas boiler with a heat pump in Luxembourg
Replacing a gas boiler with a heat pump qualifies for the same grants as an oil boiler replacement — the Klimabonus makes no distinction between fossil fuels. Here is the full breakdown of cumulative grants available in 2026.
1. Klimabonus Wunnen 2026 — up to ~€9,000
Since 1 January 2026, the Klimabonus Wunnen uses flat-rate amounts fixed in euros, independent of installation capacity. For replacing a gas boiler with an air-water heat pump, the Klimabonus can reach approximately €9,000, combining: the base grant for the air-water heat pump installation; the fossil boiler replacement bonus (integrated into base amounts since 2026); an adaptation grant for the existing heat distribution system if needed; a 15% bonus if a buffer tank is installed.
Under the old regime, the gas boiler had to be at least 10 years old to benefit from the replacement bonus. This condition has been permanently removed since 1 January 2026. Even if your condensing gas boiler is recent, you can receive the full replacement bonus. The agreement in principle must be submitted before work starts via MyGuichet.lu.
2. Enoprimes — ~€1,500
Enoprimes (Enovos/Creos programme) pays a grant for the installation of an air-water heat pump of approximately €1,500, to be claimed from your energy provider after commissioning. Unlike oil boiler replacement, there is no specific Enoprime for decommissioning a gas installation (no oil tank to eliminate).
3. Reduced VAT at 3% on all work
All renovation work in a home more than 2 years old benefits from 3% VAT instead of 17% in Luxembourg — approximately €2,800 savings on a €20,000 installation, applied automatically on the installer’s invoice.
4. Municipal grants — up to €3,000 depending on the municipality
Many Luxembourg municipalities offer complementary grants of €500–3,000. Use the Klima-Agence simulator (klima-agence.lu) or your municipality to find out the amount applicable to your address.
| Grant type | Organisation | Estimated amount | When to apply? |
|---|---|---|---|
| Klimabonus air-water heat pump (gas boiler replacement) | Luxembourg State / AEV | Up to ~€9,000 | Agreement in principle BEFORE work (MyGuichet.lu) |
| Enoprimes air-water heat pump | Enovos / Creos | ~€1,500 | After commissioning (enoprimes.lu) |
| Reduced VAT 3% | Directly on installer invoice | ~€2,800 (base €20,000) | Automatic on invoice |
| Municipal grant | Your municipality | €500–3,000 | Varies by municipality |
Costs, savings and return on investment — gas boiler → heat pump
Here is a realistic projection based on installations carried out in Luxembourg in 2026, for switching from a gas boiler to an air-water heat pump. Costs include removal of the gas boiler, gas installation decommissioning, heat pump + hydrokit + buffer tank + DHW tank, hydraulic balancing and commissioning.
| Home profile | Gross installation cost | Estimated total grants | Net cost after grants | Estimated annual savings | Net payback period |
|---|---|---|---|---|---|
| 80–100 m², good insulation, recent condensing boiler, low-T° radiators | €16,000–19,000 | €10,000–12,500 | From ~€5,500 | €700–1,200 | 5–7 years |
| 100–150 m², adequate insulation, gas boiler >15 years | €18,000–24,000 | €11,000–14,000 | From ~€7,000 | €1,000–1,800 | 5–7 years |
| >150 m², old gas boiler, radiator adaptation needed | €20,000–28,000 | €11,000–14,000 | From ~€9,000 | €1,500–2,500 | 5–7 years |
Grants include Klimabonus + Enoprimes + 3% VAT saving. Indicative data — March 2026. The payback is slightly longer than for oil boiler replacement (4–6 years), since annual savings are lower — gas being already cheaper than oil, the bill differential is less dramatic. However, installation costs and Klimabonus grants are identical.
In Luxembourg, combining an air-water heat pump with photovoltaic panels is a particularly effective strategy. The heat pump can be programmed to prioritise solar self-consumption during production hours, with buffer tank heating. This combination can reduce net grid electricity consumption by 30–40% annually. Both installations benefit from the 2026 Klimabonus and can be carried out simultaneously to optimise the administrative process.
The hybrid option: keep the gas boiler as temporary backup
You don’t have to cut completely and immediately from gas. There is a third, often underestimated path: the hybrid heat pump, which associates an air-water heat pump with an existing gas boiler (or a new low-capacity gas boiler).
How does a hybrid heat pump + gas system work?
The air-water heat pump handles all heating in normal weather conditions (generally down to −5°C or −7°C depending on the model), and the gas boiler takes over automatically during extreme cold spells or high simultaneous demand. Smart regulation manages the switchover based on outdoor temperature, the heat pump’s instantaneous COP and energy price signals.
This system is particularly relevant for: old homes with high-temperature radiators incompatible with a standard heat pump; co-ownerships with acoustic or placement constraints; owners wanting a gradual transition with maximum heating security.
Klimabonus conditions for a hybrid system
- The heat pump is non-fossil (electric air-water or geothermal)
- The heat pump covers at least 70% of the home’s annual heat needs (calculated and documented)
- The existing gas boiler used as backup is eliminated within 5 years of the installation invoice date
In practice, the Klimabonus applies fully to the heat pump portion of the system. The gas boiler maintained as backup is tolerated as a transitional solution — provided the 5-year deadline for complete removal of the fossil fuel is respected.
If you opt for a hybrid heat pump + gas system, specify this clearly to your installer from the outset. The heat pump must be sized to cover the required 70%, and the regulation must be documented for the Klimabonus application.
Project steps from A to Z
Online simulation and grants estimate
Use the Renov.lu simulator for a quick estimate of eligible grants and net project cost. This helps decide between a standard heat pump, high-temperature heat pump, or hybrid system.
Site visit and comparative quotes
The certified installer performs a thermal study (EN 12831 calculation), assesses radiator compatibility with low temperatures, checks available boiler room space, and identifies the best outdoor unit location. Compare at least 2 detailed quotes.
Klimabonus agreement in principle — BEFORE any signature
The most critical step: before signing the quote, submit your request for agreement in principle to the AEV environmental agency via MyGuichet.lu. Starting work without this prior agreement automatically results in loss of all Klimabonus grants — no exceptions. Your installer can handle this process.
Gas contract cancellation and Creos coordination
In parallel, contact your gas supplier for contract cancellation and agree on a final meter reading date. Contact Creos to schedule meter closure and removal. Coordinate gas closure timing with heat pump commissioning to avoid any heating interruption.
Installation (2–4 days depending on configuration)
Day 1: gas boiler removal, civil works start. Days 1–2: outdoor unit installation. Days 2–3: indoor unit (hydrokit), buffer tank, DHW tank, hydraulic connections, heating circuit balancing. Days 3–4: electrical connection, commissioning, regulation setup, performance testing.
Gas installation decommissioning
A certified professional seals the internal gas pipes. The Chambre des métiers acceptance request for the gas installation decommissioning is submitted. This acceptance is mandatory and separate from the heat pump acceptance.
Acceptances and grant application
The installer submits the heat pump acceptance request to the Chambre des métiers within one month of commissioning. You then assemble your Klimabonus application (invoices, commissioning certificate, acceptance report) and your Enoprimes application. Grants are generally paid within 2–6 months.
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Simulate my 2026 grants → Free quotes →Special cases: apartment, co-ownership, underfloor heating, new home
I live in an apartment with an individual gas wall boiler
The most common configuration in Luxembourg buildings from 1990–2015: each apartment has its own gas wall boiler. Replacement by an air-water heat pump is technically possible but requires installing an outdoor unit on the façade, balcony, or terrace. In co-ownership this generally requires: general assembly authorisation; verification of co-ownership rules and municipal regulations on visible façade installations; and an acoustic calculation to validate noise limits relative to neighbouring apartments.
Compact low-power air-water heat pumps specifically designed for apartments exist on the market. Ask your installer to present solutions adapted to your configuration.
Collective gas heating in co-ownership
If the building has a collective gas boiler room, replacement must be voted at a general assembly. Options at building scale include collective geothermal heat pump, connection to an urban heat network (networks exist in Luxembourg-City, Kirchberg, Esch-sur-Alzette\…), or a collective biomass boiler. These projects are eligible for specific Klimabonus grants for collective projects.
Home with underfloor heating and condensing gas boiler: the ideal heat pump profile
If your home has water-based underfloor heating (low temperature, 28–35°C) fed by a condensing gas boiler, you have the most favourable profile for a heat pump installation. Underfloor heating operates exactly at the ideal temperature for an air-water heat pump, maximising seasonal COP (sometimes up to 4.5–5 in mid-season) and minimising electricity consumption. Payback in this case can be as short as 5 years.
Recent home built with gas (less than 10 years old)
Since 1 January 2026 and the removal of the age condition, you are eligible for Klimabonus grants even if your home and gas boiler are recent. If your boiler works perfectly and your home is well insulated (class B or A), ROI will be positive but over a 7–10 year horizon. Combining with solar panels accelerates profitability and streamlines administrative processes.
Frequently asked questions about replacing a gas boiler with a heat pump in Luxembourg
My condensing gas boiler is only 6 years old. Can I still get the Klimabonus?
Yes, absolutely. Since 1 January 2026, the 10-year age condition has been permanently removed from the Klimabonus. Regardless of your gas boiler’s age, you are eligible for the full replacement bonus, provided you submit the agreement in principle before starting work. The only question is economic: with a recent, high-performing boiler, the payback period will be longer. Use our simulator to assess whether the project makes sense in the short term for your situation.
Must I cancel my gas subscription when replacing my gas boiler with a heat pump?
Not necessarily. If you have other gas appliances (hob, independent gas water heater), you can keep your gas subscription by changing tariff to eliminate the heating portion. If the boiler is your only gas appliance, full cancellation is logical and will save the fixed monthly Creos network subscription. For hybrid heat pump + gas systems, you of course keep your gas subscription for the duration of boiler use as backup.
Are my radiators compatible with an air-water heat pump if I currently have a condensing gas boiler?
In most cases, yes — and this is one of the advantages of switching from condensing gas. If your condensing gas boiler already operated at low temperature (40–50°C return), your radiators are probably sufficiently oversized to work with a standard air-water heat pump (55°C maximum). Your installer will perform a heating surface calculation during the site visit to confirm this.
Can a heat pump really heat effectively in Luxembourg in winter?
Yes — modern air-water heat pumps operate efficiently down to −15°C to −20°C depending on the model. In Luxembourg, temperatures rarely fall below −10°C (less than 5% of heating season hours), and the COP remains positive even at these temperatures (around 2.2–2.5). The heat pump must be correctly sized for the maximum heating demand of the home (EN 12831 calculation). In extreme cold, the built-in electric backup heater takes over automatically.
My home is energy class E. Should I insulate first or install the heat pump?
Ideally both together — and this is precisely what the 2026 Klimabonus encourages with its cumulative grants. If forced to choose short-term: in a class E home, a high-temperature heat pump can be installed immediately (managing the high temperatures needed), and insulation planned within 1–3 years. Once insulated, the heat pump can operate in low-temperature standard mode with significantly improved COP. Both projects are subsidised separately by the Klimabonus.
How long does a heat pump last compared to a condensing gas boiler?
A well-maintained air-water heat pump has a compressor lifetime of 15–20 years, with electronic and hydraulic components lasting 20–25 years — comparable to a condensing gas boiler. The heat pump requires annual maintenance by a certified professional, similar to the annual gas boiler service. Maintenance costs are slightly lower for a heat pump (no combustion, fewer components subject to thermal wear).
Replace your gas boiler with a heat pump in 2026 — with the best available grants
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