Thermodynamic water heater prices in Belgium in 2026
The thermodynamic water heater produces domestic hot water with a COP of 2.5 to 3.5 — two to three times less electricity than a conventional electric water heater. The Walloon and Brussels grants significantly lighten the initial investment. This guide details the 2026 ranges by capacity so your quote no longer holds any grey areas.
Indicative ranges incl. VAT, supply and fitting. Grants not deducted.
Thermodynamic water heater prices by capacity
Ranges for a thermodynamic water heater supplied and fitted, electrical and plumbing connections included. Excluding civil works and adaptation of the domestic hot water distribution circuit.
| Capacity | Ambient air plant room · indoor air intake and exhaust | Extract air mechanical ventilation · recovers extracted heat | Outdoor air split · separate outdoor unit |
|---|---|---|---|
| 200 litresStudio or couple · everyday use | 2 000– 2 600 € | 2 200– 2 800 € | 2 500– 3 000 € |
| 270 litresFamily of 3–4 people | 2 500– 3 100 € | 2 700– 3 300 € | 3 000– 3 500 € |
| 300 litres and overLarge family or heavy use | 3 000– 3 800 € | 3 200– 4 000 € | 3 500– 4 500 € |
Indicative prices incl. VAT, supply and fitting included, grants not deducted. The sizing is established during the free quote. See also the prices of all heat pumps.
What makes the price of your thermodynamic water heater vary
For the same capacity, two quotes can differ by several hundred euros. Here are the six items that really weigh on the final bill.
- Tank capacity
Capacity (in litres) is the first driver of the price. It is sized according to the number of occupants and consumption habits : 200 L for 1–2 people, 270 L for 3–4, 300 L and over for large families or heavy use.
- Air source (ambient, extract, outdoor)
The ambient-air unit draws heat from a plant room (cellar, garage) : a simpler, cheaper installation. Extract air recovers air from the mechanical ventilation : very efficient but requires a specific connection. The outdoor-air split is independent of the room, but needs an outdoor unit.
Thermodynamic water heater guide → - COP and energy performance
A COP of 3.5 uses three times less electricity than a conventional electric water heater. Premium appliances (COP ≥ 3.0) cost 200 to 400 € more to buy, but recoup that gap in 1 to 2 years of operation.
- Brand and range
Reputable brands (Thermor, Atlantic, Ariston, Viessmann) command prices 10 to 20 % higher than entry-level models, but offer longer warranties (5 to 7 years on the compressor) and guaranteed parts availability.
- Installation complexity
Replacing an existing tank (same location, same plumbing) costs markedly less than an installation in a new room. Plumbing and pipework can amount to an extra 300 to 700 €.
- Noise level and acoustic constraints
A thermodynamic water heater emits 45 to 55 dB(A) when running. For a room adjoining a bedroom or living space, a low-noise model or an acoustic enclosure (150 to 350 €) may prove necessary.
The grants that lighten the price of your thermodynamic water heater
In Belgium, installing a thermodynamic water heater to replace an electric or gas water heater entitles you to regional grants and reduced VAT at 6 %. Here are the 2026 benchmarks.
Prime Habitation
Grant for installing a high-performance thermodynamic water heater, scaled by household income and the appliance category.
- Replacement of a conventional electric or gas water heater
- COP ≥ 2.5 under standardised conditions
- Installation by an approved professional
- Increased amount for low-income households
Renolution grants
Support for installing a high-performance domestic hot water system, thermodynamic water heater included, with three income brackets.
- Thermodynamic water heater for DHW production
- Home over 10 years old
- Certified installer and itemised invoice provided
- Combinable with other Renolution grants
Get your price net of grants, within 48 h
We check your entitlements, cost it net of grant and handle the paperwork : you advance nothing more than the amount left to pay.
- We check your entitlements
Region, income, type of current appliance, age of the home : we identify every grant you can claim before we even cost it.
- We size it and cost it
Number of occupants, DHW consumption, available space : we choose the optimal capacity and air source, with an itemised quote net of grant.
- We handle the paperwork
Regional forms, technical annexes, decommissioning certificate : we manage it all.
- We deduct where possible
When the mechanism allows, the grant is taken off your final invoice. No cash advance.
Are you in Flanders ? The Mijn VerbouwPremie also covers thermodynamic water heaters — ask us for the details for your municipality.
A range in 10 seconds
Pick your tank capacity to get a ballpark figure. The free quote remains the only precise estimate tailored to your home.
Indicative estimate, excluding any plumbing works and plant room adaptation.
Replacing an electric water heater with a thermodynamic model
A concrete renovation case to make every cost item meaningful. Your project will be costed according to your precise needs.
Indicative example dated 2026, excluding any plumbing works. Request your quote for pricing tailored to your home.
Dig deeper before deciding
- Thermodynamic water heater Full guide
Everything about the technology : how it works, COP, air sources, upkeep and comparison with solar thermal.
See the full guide → - Heat pump prices, all technologies Comparison
Air-to-air, air-to-water, geothermal and thermodynamic side by side : 2026 ranges and grants grouped together.
Compare the technologies → - Heat pump grants Grants 2026
The full detail of grants available in Wallonia, Brussels and Flanders to finance your project.
Explore the grants →
Your questions about thermodynamic water heater prices
How much does a thermodynamic water heater cost in 2026?
In Belgium, expect between 2 000 and 3 000 € for a 200 L model, between 2 500 and 3 500 € for a 270 L and between 3 000 and 4 500 € for a 300 L and over — all supplied and fitted, connections included, grants not deducted.
Which capacity should I choose for my family?
As a rule of thumb, allow 50 to 60 litres per person : a couple will be happy with a 200 L, a family of 3 to 4 people will prefer a 270 L, and beyond 5 people or for heavy use (bathtub, high thermal comfort), a 300 L or more is needed.
What is the difference between ambient air, extract air and outdoor air?
Ambient air draws from the plant room (cellar, garage) : a simple installation, but the room cools down in winter. Extract air recovers the stale air from the mechanical ventilation before exhaust : very efficient. The outdoor-air split works independently of the indoor room, with an outdoor unit to fit — the most versatile solution but the most expensive.
What grants are there for a thermodynamic water heater in Belgium?
In Wallonia, the Prime Habitation can reach 1 500 € depending on income and technical conditions. In Brussels, the Renolution grant goes up to 1 200 €. In both regions, the amount depends on income and the type of appliance replaced. In Flanders, the Mijn VerbouwPremie can also be claimed.
Is the thermodynamic water heater noisy?
Current models emit 45 to 55 dB(A) when running — comparable to a fridge. For a room adjoining a bedroom, a low-noise model or an acoustic enclosure (150 to 350 €) may prove useful. Your installer assesses the situation during the quote.
Is VAT reduced for a thermodynamic water heater?
Yes. For renovation of a home over 10 years old, VAT is 6 % instead of 21 %. That is a real saving on a budget of 2 000 to 4 500 €. We check your eligibility from the first contact and apply it directly on the quote.
Your exact price, costed and net of grants
The ranges give the order of magnitude — the quote gives the figure. Sizing, choice of air source, grants calculated and deducted, a single point of contact. In under a minute.
- Free and without obligation
- Grants & 6 % VAT calculated and deducted
- Costed quote within 48 h, working hours