Heat pumps have moved from a niche technology to the most actively incentivised heating option in Italy in 2026. The primary driver is the Conto Termico 3.0 programme managed by GSE, which reimburses up to 65% of installation costs directly to the applicant's bank account — no need to wait through ten annual income-tax deductions.
This article covers the practical aspects of choosing, sizing and installing an air-to-water heat pump in an Italian home: what the system actually does, where it works well, and the specific numbers you need before calling an installer.
How air-to-water heat pumps work
An air-to-water heat pump extracts heat from outdoor air and transfers it into the home's hydronic circuit — the same pipes and radiators or underfloor heating used by a conventional boiler. The outdoor unit contains a refrigerant circuit; a compressor increases the refrigerant's temperature; a heat exchanger releases that heat into the water. The process consumes electricity but produces three to five times more heat energy than it consumes, giving a Seasonal Coefficient of Performance (SCOP) or JAZ value between 3 and 5.
In practical terms: if the electricity tariff is €0.25/kWh and the JAZ is 4, the effective cost of heat is €0.063/kWh — competitive with natural gas at current prices and significantly below GPL.
Climate zone compatibility
Italy is divided into six climate zones (A through F) based on degree-days. Air-to-water heat pumps are effective across zones A through E without particular concern. Zone F (Alpine areas above approximately 1,400 m) requires a cold-climate heat pump rated for operation down to −20°C, or a hybrid configuration pairing the heat pump with a backup boiler that activates below −5°C.
Modern cold-climate units from Bosch, Viessmann, Daikin and Vaillant maintain rated output down to −15°C and can operate at reduced capacity to −25°C. The older concern about heat pumps losing efficiency in cold winters applies mainly to equipment produced before 2018.
Compatibility with existing radiators
The most common reason heat pumps underperform in renovations is radiator mismatch. A standard gas boiler runs its circuit at 70–80°C supply temperature. A heat pump is most efficient at 35–55°C supply. Radiators sized for 70°C water deliver noticeably less heat when running at 50°C.
Before committing to a heat pump installation, an installer should calculate the heat load of each room and compare it against the output of existing radiators at the lower supply temperature. In many Italian apartments built before 1990, the radiators are oversized for the actual heat load, meaning they already deliver sufficient output at 50°C. In others, selective replacement of radiators in the coldest rooms (typically bathrooms and north-facing bedrooms) resolves the issue at a fraction of full replacement cost.
Underfloor heating, where present, is the best match for heat pumps: typical supply temperatures of 35–40°C allow JAZ values at the top of the range.
Installation cost estimates (2026)
The following figures are typical for a 150 m² Italian house in climate zone D or E, with an existing hydronic system requiring limited modification:
- Air-to-water heat pump unit and installation: €10,000–€18,000 (including labour, connections, controls)
- Domestic hot water cylinder (if not included): €1,200–€2,500
- Partial radiator replacement (2–4 radiators): €800–€2,000
- Hydraulic separation buffer tank: €400–€800
Total installed cost typically falls in the €12,000–€22,000 range before incentives. After Conto Termico 3.0 at 65%: effectively €4,200–€7,700 net outlay for a system with a 15–20 year service life.
Conto Termico 3.0: the incentive in detail
The Conto Termico 3.0 is a direct incentive — not a tax deduction — managed by the Gestore dei Servizi Energetici (GSE). Private households can claim up to 65% of eligible expenditure. Amounts under €15,000 are paid in a single transfer within 90 days of application approval.
Eligible interventions include the replacement of any existing heating system (gas, oil, or older heat pump) with a new high-efficiency heat pump meeting the efficiency thresholds set in the D.M. 16/02/2016. The application is submitted through the GSE portal within 60 days of the end of works.
Key documents required: fiscal receipts, certificate of installation by a qualified technician (D.Lgs 28/2011), technical datasheet confirming COP and SCOP values, and the updated building energy certificate (APE) after installation.
Ecobonus as an alternative route
Households with sufficient IRPEF tax liability may prefer the Ecobonus 50% deduction over ten years, available for primary residences (first home). The deduction applies to the full installation cost up to the eligible maximum, but the benefit accumulates slowly across a decade — less attractive than the GSE direct payment for most households. The hybrid route — combining Conto Termico for the heat pump unit itself and Bonus Ristrutturazioni for ancillary work — sometimes yields the best financial outcome and warrants a comparison calculation before applying.
Hybrid systems
A hybrid system pairs an air-to-water heat pump with a condensing gas boiler. The control unit selects whichever source is cheaper at any given moment: the heat pump during mild weather, the boiler when temperatures drop below the heat pump's optimal operating threshold (typically 0°C to −5°C). Hybrid systems qualify for Conto Termico incentives when the heat pump component meets the required efficiency thresholds.
For households in zones E and F with existing gas infrastructure and radiators sized for high supply temperatures, a hybrid system is often the lowest-risk path to significant energy cost reduction without requiring radiator replacement.
Practical checklist before requesting quotes
- Confirm the building's climate zone via the ENEA climate zone map.
- Obtain or commission a heat loss calculation (certificazione energetica, class APE).
- Check existing radiator dimensions and note the current boiler supply temperature setting.
- Identify available outdoor space for the unit (minimum clearances from windows and property boundaries vary by municipality).
- Confirm the electrical supply capacity — most residential heat pumps require a 3-phase connection for units above 8 kW.
- Request at least three quotes from qualified technicians registered with ENEA for Conto Termico applications.