The most versatile heat pump: it feeds your radiators or underfloor heating and produces domestic hot water, by drawing heat from the outside air. The ideal replacement for an oil or gas boiler, with high efficiency all year round.
The figures that matter for a quality air-to-water heat pump, installed by our teams. Concrete benchmarks, not marketing.
For 1 kWh of electricity, an air-to-water unit delivers 3.5 to 4.8 kWh of heat over the season. Efficiency climbs with underfloor heating (low-temperature water) and good sizing.
High-temperature models reach 55 to 65 °C and work with existing radiators. With underfloor heating, water at 35 °C is enough and maximises efficiency.
Paired with a tank, it supplies hot water for the whole family. The tank heats the water during the most efficient hours of the day.
The monobloc keeps everything in the outdoor unit (no refrigerant indoors); the split separates the outdoor unit and an indoor module. We choose based on space and layout.
Recent air-to-water heat pumps heat down to −20 °C outside. A built-in electric backup takes over during the rarest cold snaps.
It connects to your existing heating circuit and replaces the boiler. In renovation, the radiators are often kept after being checked.
* Indicative values for standard-range models. Real-world performance depends on the model, the emitter and the insulation of the home — confirmed during the technical survey.
No heat pump is perfect for every project. Here, honestly, is where air-to-water stands out and where another solution is a better fit.
It is the heat pump for complete central heating. A few cases where it stands out:
The most common case: we remove the old boiler, connect the heat pump to the existing circuit and claim the replacement grants.
On low-temperature underfloor heating, air-to-water performs at its best: even comfort and maximum efficiency.
Paired with a tank, it absorbs peaks in hot-water consumption without falling back on direct electric or gas.
For a supplement or summer cooling without a water circuit, the air-to-air heat pump is simpler. And if you are hesitant about removing the boiler, the hybrid heat pump combines both during the transition.
A 22-year-old oil boiler, thirsty and at the end of its life. We installed an air-to-water heat pump connected to the existing radiators (checked beforehand) with a 200 L hot-water tank. The Wallonia grants and the 6% VAT were deducted from the bill.
5.0/5 · 3verified reviews
« Châssis, panneaux et pompe à chaleur en une seule fois : on a eu un seul devis, un seul planning et zéro paperasse pour les primes. Le résultat est impeccable et notre facture d'énergie a chuté. On ne pensait pas que ce serait aussi simple. »
« Passage du mazout à une pompe à chaleur air-eau. Chantier propre, anciens radiateurs conservés. La maison est mieux chauffée pour bien moins cher. »
« PAC air-air réversible installée avant l'été. Confort été comme hiver, et le SAV répond vite. Très satisfait du suivi. »
Air-to-water is the most versatile for the whole house. Depending on your budget, your emitters and severe cold, another type may complement or replace this choice.
| Critère | Air-to-water heat pumpVous êtes ici | Air-to-air heat pumpVoir la gamme → | Hybrid heat pumpVoir la gamme → |
|---|---|---|---|
| Central heating (water) | Yes, complete | No, forced air | Yes, complete |
| Domestic hot water | Yes, with tank | No | Yes, with tank |
| Investment | €€€ — mid-range | The most affordable | €€€ — mid-range |
| Cooling in summer | Depends on model | Yes, built in | Depends on model |
| Severe cold | Electric backup | Supplement useful | Boiler takes over |
| Grants 2026 | The highest | More limited | Supported |
| Best for | Replacing a boiler, whole house | Supplement, living space, cooling | Smooth transition |
Simpler and reversible: fast heating and summer cooling, without a water circuit. Ideal as a supplement or per room.
Compare with air-to-air →The best efficiency thanks to the stable heat of the ground. A heavier investment, maximum performance over time.
Discover geothermal →Keeps the boiler as backup for cold snaps: a reassuring transition towards the heat pump.
See hybrid →Air-to-water is the most grant-supported heat pump. Check the amount based on your region and income.
Calculate my grants →Installed price ranges and payback times by output and your current consumption.
See the prices →An overview of our heat pump solutions in Belgium: types, sizing, grants and installation gathered on one page.
Back to the heat pump guide →The price depends on the output, whether a hot-water tank is included and the emitter (radiators or underfloor). Here are some benchmarks for installed equipment.
See heat pump prices & grants in detail →* Indicative ranges for installed equipment, excluding specific configurations. A costed estimate is provided with your free quote.
Often yes. A high-temperature air-to-water heat pump feeds standard radiators. We first check that their exchange surface is sufficient for the target flow temperature; a few undersized radiators may be replaced to guarantee comfort.
The monobloc keeps the entire refrigerant circuit in the outdoor unit: nothing to handle on the refrigerant side indoors. The split separates the outdoor unit from an indoor module. The choice depends on available space, the line length and the layout of the home.
Yes. Recent air-to-water units heat down to about −20 °C outside, with efficiency that drops as it gets colder. A built-in electric backup secures the rare, most intense cold snaps.
It is strongly recommended. Good insulation lets you lower the flow temperature, hence increase efficiency, and avoid oversizing the heat pump. We assess insulation during the survey and prioritise the works if needed.
Air-to-water is the most supported heat pump: a regional grant (Wallonia or Brussels) that can reach several thousand euros depending on your income, plus 6% VAT in renovation. We calculate your eligibility before the quote.
It depends on the energy replaced. Against an oil boiler, the annual savings are significant and, with grants deducted, the payback is often a matter of a few years. We cost your specific case in the quote, based on your real consumption.
Free technical survey, emitter validation, grants calculated. Describe your project in under a minute.