Boiler replacement in Belgium in 2026: what does it cost by type?
Short answer: In Belgium, a new gas condensing boiler typically costs €2,000 to €5,500, installed and usually incl. VAT (21%). An oil condensing boiler costs €4,500 to €8,000 but is no longer allowed everywhere, and an air-to-water heat pump costs €8,000 to €18,000. The spread depends on output, combi or heating-only, flue work and finish level. A service visit costs about €100 to €250.
Prices in this article are indicative Belgian market ranges, not Alpha Services Benelux's price list. Your fixed price is in the quote.
What does a new boiler cost in Belgium in 2026?
For a gas condensing boiler, expect €2,000 to €5,500 including installation and usually VAT. These are market ranges: sources differ, and the price depends on finish level, output and the condition of your system.
| Type | Indicative price | Note |
|---|---|---|
| Gas condensing boiler, heating only | €2,000 – €3,500 | Separate hot water cylinder |
| Gas combi boiler (heating + hot water) | €2,500 – €5,500 | No separate cylinder or geyser needed |
| Oil condensing boiler (only where still allowed) | €4,500 – €8,000 | Excl. any new storage tank |
| Air-to-water heat pump | €8,000 – €18,000 | Depends on output and hot water |
One source quotes lower figures for a gas boiler. We use the wider range, because flue work and finishing often appear as separate lines on the invoice.
What drives the price of a boiler replacement?
Boiler type, output and flue work matter most. The installation itself and the work around the boiler come next.
- Fuel and type: gas is clearly cheaper than oil or a heat pump.
- Combi or heating-only: a combi costs more but saves you a separate cylinder.
- Output and brand: a larger or floor-standing unit costs more.
- Flue: a condensing boiler needs a special double-walled flue. Without one, costs rise.
- Condition of the system: pipework, radiators and the circuit may need work.
| Item | Indicative price |
|---|---|
| Installation labour | €500 – €1,500 |
| Flue gas outlet | €300 – €800 |
| Removing the old boiler | €50 – €600 |
| Flushing the heating circuit (sludge removal) | €400 – €1,200 |
| Decommissioning an oil tank | €800 – €2,000 |
Whether a figure is excl. or incl. VAT differs per source. Use the widest range and ask for VAT to be shown clearly on your quote.
Switching from oil to gas or a heat pump: what changes?
Leaving oil costs more than a like-for-like gas swap. A new oil boiler runs €4,500 to €8,000, a heat pump €8,000 to €18,000.
A new oil boiler is no longer allowed everywhere:
- Brussels: new oil boilers have been banned since 1 June 2025, including replacements in existing buildings. The only exception is a boiler running solely on renewable liquid fuel, and such fuels are not yet approved for heating in Belgium.
- Flanders: since 1 January 2022, an oil boiler may only be replaced if there is no gas grid at the property. Fluvius can confirm whether you can connect.
- Wallonia: replacement in existing buildings is still allowed for now, until 1 January 2031.
Existing boilers can stay in use and repairs remain possible.
For a heat pump, the house is what counts. A well-insulated home, with EPB class C or better as a starting point, gets the most from low flow temperatures. In a poorly insulated home, have a professional assess the situation first. A heat pump may also need changes to the electrical installation, see our electrician page.
Moving from oil to gas means thinking about the gas grid connection and the tank. Decommissioning an oil tank costs €800 to €2,000.
VAT on a new boiler: 21% or 6%?
A new gas or oil boiler has been taxed at 21% VAT since 29 July 2025, even in homes older than 10 years. The 6% rate remains for servicing, repairs and heat pumps.
The change was originally planned for 1 July 2025 and took effect when the programme law was published in the Belgian Official Gazette on 29 July 2025. Transitional rules covered quotes and contracts concluded before that date. Ask your contractor to state the applied rate and the reason on the quote.
To get 6% on a heat pump, the usual conditions apply: a dwelling older than 10 years, private use and work invoiced by a VAT-registered contractor to the end consumer. Materials you buy yourself stay at 21%.
Also check loans and any aid on your region's official portal (vlaanderen.be/mijn-verbouwpremie, energie.wallonie.be or Homegrade in Brussels).
Mandatory boiler servicing by region
In Brussels, a gas boiler is checked every 2 years and an oil boiler every year. In Wallonia it is every 3 years for gas up to 100 kW and yearly for oil.
| Region | Gas | Oil |
|---|---|---|
| Brussels | Every 2 years | Yearly |
| Wallonia | Every 3 years (≤ 100 kW) | Yearly |
| Flanders (from 20 kW) | Every 2 years | Yearly |
An approved technician does the work and issues a certificate. Keep it: you may need it when selling, letting or after damage.
A service visit costs about €100 to €200 for gas and €150 to €250 for oil. Maintenance contracts run from €80 to €250 a year, depending on cover and call-out priority.
When should you replace a boiler?
A gas boiler lasts 15 to 20 years on average. From around 15 years, have a professional assess your boiler.
- Age: modern condensing boilers reach about 98% efficiency, older units often below 85%.
- A rising energy bill with unchanged heating habits.
- Frequent breakdowns or noises such as ticking and banging.
- Repairs above 50% of the price of a new boiler, especially after 12 years.
Avoid waiting for a mid-winter breakdown: an emergency job costs more than a planned replacement. A replacement usually takes one day, sometimes two if the flue or circuit needs adapting.
Comparing quotes without surprises
Only compare quotes that cover the same scope. A low price without flue work or removal of the old boiler is rarely the cheaper one.
- Ask for a quote after a site visit, not just from photos.
- Check that output, brand and type (combi or heating-only) are stated.
- Have the flue, removal of the old boiler and any flushing itemised separately.
- Check the VAT rate and whether the first service or inspection is included.
- Ask about warranty terms for both the unit and the installation.
Alpha Services Benelux (Dilbeek), active since 2014, works with its own team and gives a fixed written quote after a site visit. See our boiler and heating page and our renovation work. For heating breakdowns there is 24/7 emergency service for plumbing, electrical and heating on 0485 44 55 12. Prices in this article are market ranges, not the company's price list.
Fixed quote after a site visit
Alpha Services Benelux does the work with its own team, active since 2014. VAT BE 0541.320.178.
Request a quoteFrequently asked questions
How much does it cost to replace a boiler in Belgium?
For a gas condensing boiler, expect €2,000 to €5,500 in 2026, installation included and usually VAT. An oil condensing boiler costs €4,500 to €8,000 but is no longer allowed everywhere. The price depends on output, type, flue work and finish level.
Is boiler servicing mandatory in Belgium?
Yes, by an approved technician. Gas: every 2 years in Brussels and Flanders (from 20 kW), every 3 years in Wallonia up to 100 kW. Oil: yearly everywhere. Keep the certificate, which you may need when selling, letting or after damage.
How much does a boiler service cost?
On average €100 to €200 for a gas boiler and €150 to €250 for an oil boiler. A maintenance contract roughly runs €80 to €250 a year, depending on cover and priority call-outs.
How long does a gas boiler last and when should I replace it?
A gas boiler lasts 15 to 20 years on average. Around 15 years, with frequent breakdowns, or when a repair would exceed 50% of a new boiler's price, have a professional assess whether replacement makes more sense.
What VAT applies to a new boiler?
A new gas or oil boiler has carried 21% VAT since 29 July 2025, even in homes older than 10 years. Servicing, repairs and heat pumps stay at 6% under conditions. Have the applied rate written on your quote.
Can I still install a new oil boiler?
It depends on the region. Not in Brussels since 1 June 2025. In Flanders only if there is no gas grid at the property (since 1 January 2022). In Wallonia, replacement in existing buildings is still allowed for now, until 1 January 2031.
Is a heat pump much more expensive than a gas boiler?
Yes, upfront. An air-to-water heat pump costs €8,000 to €18,000 installed, a gas condensing boiler €2,000 to €5,500. A heat pump also needs a well-insulated home and sometimes electrical upgrades.
Sources
- Wat kost een condensatieketel? 2026 Prijzenoverzicht — Homedeal
- Condensatieketel: Prijs van de Investering en Premies 2026 — Renovatie-gids
- Gasketel vervangen 2026: prijs, wanneer en opties — Renovatie-gids
- Prix installation chaudière Wallonie 2026 : tarifs complets gaz, mazout et condensation — Les Pros de Ma Ville
- Remplacement chaudière - Prix et devis 2026 — AVS Service
- Lucht/water-warmtepomp: werking, prijzen en premies in België in 2026 — Facq
- Btw op gas- en stookolieketels vanaf 29 juli 2025 van 6% naar 21% — Coolen
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- Nieuwe mazoutketel plaatsen: wetgeving per gewest — in4fuels
- Onderhoud cv-installatie in Vlaanderen: wat zegt de wet? — in4fuels
- Onderhoud cv-installatie in Brussel: wat zegt de wet? — in4fuels
- Entretien chaudière obligatoire en Belgique (2026) — Trustup
- Ketelonderhoud België: verplicht? Hoe vaak en wat kost het? — Selectra
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- Uw verwarmingsketel laten keuren: hoe vaak moet het en waarom? — P&V