Complete guide to the costs of a heat pump in 2026
Behind an overall range lie very distinct items: outdoor unit, hot water tank, hydraulic and electrical connections, labour. This guide breaks down every euro so your quote no longer has any grey areas.
Indicative ranges incl. VAT, grants not deducted.
Cost per item according to the HP technology
Each line corresponds to an item that is actually invoiced. The totals per technology correspond to the fitted + connected ranges, including 6% renovation VAT.
| Item | Air-to-air reversible split | Air-to-water heating + DHW | Geothermal ground-water or water-water |
|---|---|---|---|
| Outdoor unitCompressor, heat exchanger, fan | 1 500–3 500 € | 3 000–6 000 € | 4 000–8 000 € |
| Indoor unit / tankInternal hydraulics + DHW tank | — | 1 500–3 000 € | 1 500–2 500 € |
| Connections + mountingHydraulic, electrical, commissioning | 1 000–2 000 € | 1 500–4 000 € | 2 000–4 000 € |
The ranges are given with 6% VAT included for the renovation of a home more than 10 years old. Excluding adaptation of the existing heating network (low-temperature radiators, underfloor heating). Details by technology: air-to-air, air-to-water, geothermal.
The 6 factors that influence the cost of a HP
For an identical technology, two projects can differ by several thousand euros. Here is why.
- Chosen technology
Air-to-air, air-to-water or geothermal: this is the first determinant. Geothermal costs two to three times more to install, but offers the best COP (coefficient of performance) and the highest grants.
- Sized capacity
A HP is sized on the home’s heat losses. A poorly insulated house requires a higher capacity, which increases the cost of the outdoor unit. A prior audit avoids oversizing.
- Adapting the heating network
If your current radiators are too small to run at low temperature (45 °C), they must be replaced or underfloor heating added. This item can add €2,000 to €6,000.
HP and low-temperature radiators → - Geothermal drilling or collectors
For a geothermal HP, vertical drilling (80 to 150 m deep) or laying horizontal collectors represents 30 to 40% of the total budget. The ground of your plot determines the method.
- Electrical connection
A 10 kW air-to-water HP draws 3 to 4 kW at peak. The sub-panel sometimes needs reinforcing and an appropriate residual-current device added. Allow €400 to €900 depending on the existing installation.
- Brand and warranty
Premium brands (Daikin, Mitsubishi, Viessmann) carry prices 15 to 25% higher than entry-level ranges, but offer better warranties (5 to 10 years) and proven after-sales support.
See the HP brands →
The grants that reduce the real cost of your HP
In Belgium, replacing fossil heating with a HP entitles you to significant regional grants and reduced VAT at 6%. The amounts below are valid in 2026.
Prime Habitation
Grant for replacing a fossil generator (oil, gas, coal) with a high-performance heat pump, scaled according to household income.
- Replacement of a fossil generator (oil, gas, coal)
- COP ≥ 3.5 (A++ label or higher)
- Prior home audit for the highest amounts
- Amount increased for low incomes
Renolution grants
Support for installing a high-performance heat pump, with three income categories (low, medium, high) and a bonus for less efficient homes.
- HP for heating or domestic hot water production
- Home more than 10 years old
- Certified HP installer and itemised invoice provided
- Combinable with other Renolution grants (insulation, glazing)
Get your price net of grants within 48h
We check your entitlements, we cost it net of grant and put together the application: you pay nothing more than the remaining balance.
- We check your entitlements
Region, income, current type of heating, age of the home: we identify all the available grants before even costing.
- We size it and cost it
Simplified heat assessment, choice of the HP suited to your home, detailed quote item by item, net of grant.
- We handle the application
Regional forms, technical annexes, certificate of decommissioning of the fossil heating: we manage everything.
- We deduct where possible
When the mechanism allows it, the grant is deducted from your final invoice. No cash advance.
Are you in Flanders? The Mijn VerbouwPremie also covers the installation of a HP — ask us for the details for your municipality.
Estimate your budget in 10 seconds
Choose the technology to get an all-inclusive cost range. The free quote remains the only precise estimate tailored to your home.
Indicative estimate excluding adaptation of the existing heating network (radiators, underfloor heating).
Replacing an oil boiler with an air-to-water HP
A concrete renovation case to bring each cost item to life. Your project will be costed according to your precise needs.
Indicative example dated 2026, excluding adaptation of existing radiators. Request your quote for a costing tailored to your situation.
Dig deeper before deciding
- Heat pump Complete guide
Technologies, COP, sizing and maintenance brought together on the HP silo pillar page.
See the full guide → - Electricity consumption Annual bill
How much a HP consumes day to day and how to optimise the electricity bill.
Calculate the consumption → - HP grants By region
The complete details of the grants available in Wallonia, Brussels and Flanders for 2026.
Explore the subsidies →
Your questions on the costs of a heat pump
What are the cost items of a heat pump?
An air-to-water HP comprises three main items: the outdoor unit (€3,000–6,000), the indoor unit with DHW tank (€1,500–3,000) and the hydraulic + electrical connections with commissioning (€1,500–4,000). In total, a fitted air-to-water HP costs between €8,000 and €15,000 incl. VAT before grants.
Does a HP cost more than a gas or oil boiler?
To install, yes: an air-to-water HP costs €8,000–15,000 versus €4,000–7,000 for a condensing boiler. But the running cost is 40 to 60% lower thanks to the COP (3 to 5 kWh of heat for 1 kWh of electricity). The grants and 6% VAT close part of the gap from the very first year.
Is the electrical connection included in the price?
Yes, in wendows quotes. The electrical connection (dedicated sub-panel, protective circuit breaker, cabling) is included in the range. If your electrical installation is old or undersized, a supplement may be needed — it is costed in the quote.
Do the radiators need replacing to switch to a HP?
Not always. A modern air-to-water HP can run up to 55 °C, which suits radiators of a reasonable size. If your radiators are too small, they need to be sized for 45 °C max, which can entail a partial replacement (€1,000–4,000). A prior heat assessment identifies this.
What is the cost of a geothermal HP?
A ground-water geothermal HP represents €15,000–25,000 supplied and fitted, drilling included. The drilling (80 to 150 m deep) alone represents 30 to 40% of the budget. In return, it is the most efficient technology (COP 4–6) and the Walloon grants go up to €6,000.
How long does it take to pay off a HP replacing an oil boiler?
With 2026 energy prices (oil > €1.00/L, electricity ≈ €0.25/kWh), the return on investment of an air-to-water HP is between 5 and 8 years thanks to fuel savings and grants. Households heating with oil benefit from the best return, because the fuel cost gap is the largest.
Your exact cost, item by item, net of grants
This guide gives the orders of magnitude — your quote gives the real figures. Heat assessment, suitable sizing and grants calculated and deducted: a single point of contact, a single appointment.
- Free and no obligation
- Grants & 6% VAT calculated and deducted
- Quote costed item by item within 48 business hours