I.ON installs air-to-water, geothermal and water-to-water heat pumps in the cantons of Vaud, Geneva, Fribourg and Neuchâtel. Thermal study, sizing, grant applications and maintenance handled by our in-house team, no subcontracting.
Three technologies
The choice depends on your land, insulation level and existing distribution system. The technical study identifies the optimal solution for your situation.
Captures energy from the outside air, operates down to -20 °C. No excavation required, fast installation. The most common solution when replacing an oil or gas boiler.
Extracts heat from the ground via vertical borehole probes (60 to 200 m). Ground temperature is stable year-round, delivering a higher SCOP than air-to-water. Also enables passive cooling in summer.
Uses groundwater (constant >10 °C). Exceptional COP but requires a cantonal permit and a hydrogeological study. Reserved for suitable configurations only.
Partner manufacturers
Daikin (Japan), Mitsubishi Electric (Japan), Vaillant (Germany), Stiebel Eltron (Germany), Buderus (Germany), Alpha Innotec (Germany), Panasonic (Japan). All offer manufacturer warranties of 5 to 10 years depending on the model, extended by our performance guarantee.
Our approach
Calculation of heat loss according to SIA 384/2 or simulation. Analysis of the existing building, radiators or underfloor heating, and hydraulic circuit. Identification of the correct sizing (oversizing = short cycling, undersizing = resistive backup).
Air-to-water, geothermal or water-to-water depending on your land, budget and resale horizon. Evidence-based recommendation from the thermal simulation, not manufacturer marketing.
Submission of the cantonal Buildings Programme file BEFORE signing. Grid operator notification. For geothermal: cantonal permit + geotechnical study. Everything handled on your behalf.
Air-to-water: 2 to 4 days on site. Geothermal: 5 to 10 days including drilling. Removal of the old heating system and oil tank neutralisation included. Existing heating remains operational until switchover.
Setting of heating curves for your rooms and lifestyle. Monitoring through the first heating season with adjustments. Contractual performance guarantee stated in the quote.
Detailed pricing
Indicative gross prices in Western Switzerland, old heating removal included. The detailed quote accounts for cantonal grants and tax deductions, which can bring the effective net cost down to 60 % of the gross price shown.
| Configuration | Gross | Detail |
|---|---|---|
| Air-to-water heat pump, house 100–150 m² | 32'000 – 42'000 CHF | Gross installed, old boiler removal included. Net after grants: 21,000–28,000 CHF. |
| Air-to-water heat pump, house 150–200 m² | 38'000 – 48'000 CHF | For a standard house with radiators or underfloor heating. |
| Geothermal heat pump, house 100–180 m² | 55'000 – 78'000 CHF | 2–4 borehole probes included. Higher SCOP than air-to-water. |
| Geothermal heat pump, house 200+ m² | 70'000 – 95'000 CHF | For large houses, new build or major renovation. |
| Water-to-water heat pump (aquifer), where permissible | 75'000 – 110'000 CHF | Reserved for very specific configurations with cantonal permit. |
Who is it for
The most common case. Oil is no longer permitted as a new replacement in the majority of Western Swiss cantons. Air-to-water heat pumps technically replace the boiler without reworking the hydraulic circuit in 9 out of 10 cases.
Vertical geothermal is well worth considering. Integrating the boreholes during earthworks reduces the relative extra cost. Long-term performance is superior to air-to-water.
Geothermal wins on winter performance. The ground maintains its temperature even in severe cold, unlike air-to-water whose COP drops at -10 °C.
Collective air-to-water or shared geothermal. Cantonal grants apply to the landlord, and part of the cost can be passed on to tenants under tenancy law.
Installation and accessories
A heat pump produces 20 to 40 L of condensate per day in winter, and its compressor generates low-frequency vibrations and noise. The outdoor unit installation is not a detail: drainage, acoustic decoupling, compliance with Swiss noise regulation (OPB) at the property boundary. Here are the options we offer in addition to the standard package.
Important: under every installation (gravel or pozzolan) we systematically lay a layer of geotextile fabric. It blocks weeds, prevents soil from creeping into the gravel and lets condensate drain through. Without it, the mineral bed becomes useless within 3 to 5 years.
Drains condensate (up to 40 L/day in winter), absorbs low-frequency vibrations, prevents tall weeds from blocking the unit's air intake. Modern graphite finish — matches contemporary façades.
Same drainage and acoustic function, but reflects summer heat — the unit overheats less in summer, preserving its COP in cooling mode. Mediterranean look.
Warm-tone limestone gravel — standard drainage and acoustic, natural finish that blends with garden landscaping (hedges, wooden decking, garden paths).
Porous volcanic rock, premium drainage and enhanced acoustic insulation (2-3 dB(A) gain vs gravel). Intense terracotta tone, matches tiles and traditional rendered façades.
Black volcanic lava, drainage and acoustic premium identical to red, but raw mineral finish. The architectural choice for contemporary integration with wooden terraces or polished concrete.
High-density rubber/foam block placed between the unit and the ground, with aluminium frame and built-in spirit level. Suppresses low-frequency vibrations transmitted to the building (wood flooring, concrete slab, shared wall). Essential when the unit sits on a slab continuous with the house.
Perimeter acoustic wall with absorbent panels — measured gain of 8 to 12 dB(A) depending on configuration. Often integrable with vegetated cladding (bamboo, ivy) to disappear into the garden. Becomes mandatory when the noise level at the property boundary exceeds the OPB DS II value (pure residential zone).
Grants and subsidies
Vaud: 4,000 to 9,000 CHF depending on output. Geneva (GEnergie), Fribourg, Neuchâtel: comparable amounts. Application must be submitted BEFORE signing the quote. Processing time 6–10 weeks.
Several municipalities in Vaud (Lausanne, Nyon, Morges, Renens), Geneva and Fribourg add local bonuses of 500–2,500 CHF. To be checked case by case.
The net cost after grants is 100 % deductible from taxable income. At a marginal rate of 27 %, tax saving of 5,500 to 9,500 CHF on a standard air-to-water heat pump.
If the heat pump is part of a broader project (insulation + heating), an additional cantonal bonus of 15–30 % may apply to the sum of individual grants.
Frequently asked questions
A heat pump captures thermal energy from the air, ground or water and concentrates it to heat your home. To produce 100 % of the heat you need, it only consumes 25 to 35 % in electricity — the remaining 65 to 75 % come free from the environment.
The seasonal COP (SCOP) varies by type: 3.5 to 4.5 for air-to-water, 4.5 to 5.5 for vertical geothermal. We contractually guarantee the seasonal COP calculated during the study.
Budget 32,000 to 48,000 CHF gross for a well-sized air-to-water unit, 55,000 to 80,000 CHF for geothermal. Cantonal grants amount to 4,000 to 9,000 CHF depending on the canton and output. With tax deductions, the effective net cost falls to 21,000–32,000 CHF for a standard air-to-water unit.
Yes. Modern air-to-water heat pumps (Daikin Altherma 4 H, Vaillant aroTHERM plus, Stiebel Eltron WPL-A, Panasonic Aquarea T-CAP, Alpha Innotec hybrox, Buderus Logatherm WLW176i) operate down to -20 °C with a reduced COP. Geothermal is never affected by outdoor temperature since it draws from the stable-temperature ground. No electric backup is required for correctly sized installations.
An air-to-water heat pump is installed in 2 to 4 days on site. Geothermal requires 5 to 10 days, mainly for borehole drilling. The existing heating remains operational until the final switchover.
Not necessarily. Many oil heating systems from the 1980s and 1990s are originally oversized, which allows the heat pump to operate at 50 °C flow temperature without changing the radiators. When some radiators are undersized, we replace 2–3 targeted units rather than the entire system.
On a house consuming 3,000 litres of oil per year (approximately 3,900 CHF/year), an air-to-water heat pump reduces the heating bill to 1,700–2,400 CHF in electricity. A saving of 60 to 70 %. Over 20 years, cumulative savings exceed 30,000–60,000 CHF, comfortably covering the switch to a heat pump.
It is neutralised and removed. This is included in serious quotes, at 1,500 to 3,500 CHF depending on volume and accessibility. The freed space becomes a utility room, workshop or storage. Underground tanks may require more extensive work.
Strongly recommended. A boiler that fails in the middle of winter puts the owner in an emergency position: no time to compare quotes, no time to put together the grant application, and often the oil has to be reconnected temporarily. Planning 6 to 12 months ahead changes everything.
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Lire l'articleClient reviews · Heat pump
“Installation d'une pompe à chaleur en remplacement d'un potager à bois pour une villa achetée en 2025. I.ON a accepté de maintenir le prix du devis réalisé plus d'une année avant par la propriétaire précédente. L'ensemble des travaux a été effectué par une équipe très compétente et sympathique. Tout s'est bien déroulé dans les délais fixés. I.ON ne m'a pas laissé tomber lorsqu'il a fallu faire fonctionner les panneaux thermiques existants avec la pompe à chaleur via le régulateur pour tout automatiser.”
“Une expérience irréprochable ! Nous avons fait appel à cette entreprise pour le remplacement de notre chaudière à gaz et du boiler. Le travail est très professionnel : les délais ont été respectés et le devis initial a été parfaitement tenu. L'équipe sur place était non seulement agréable, mais aussi très discrète durant toute la durée du chantier. Le résultat est très satisfaisant et le nouvel équipement fonctionne à merveille. Je recommande vivement !”
“Pour le remplacement de notre chaudière à gaz, nous avons décidé d'équiper notre PPE de 8 appartements (24 personnes) avec pompe à chaleur et panneaux photovoltaïques. Entre les grands groupes peu intéressés et les PME du secteur sanitaire surtout actives sur les villas, seul I.ON a su nous écouter et proposer un équipement correctement dimensionné pour chauffer notre immeuble et produire 900 litres d'eau chaude sanitaire par jour. Mention excellente pour l'équipe interne : discrète mais très efficace dans ses relations avec les autorités cantonales et l'administration de notre PPE. Aucun copropriétaire n'a eu à subir de gêne pendant les travaux.”
“Je tiens à exprimer ma totale satisfaction concernant l'installation de notre pompe à chaleur air-air par la société I.ON. De la première prise de contact à la mise en service finale, l'expérience a été exemplaire. Leurs experts ont pris le temps d'étudier nos besoins spécifiques et nous ont proposé une solution parfaitement dimensionnée. La phase de mise en œuvre s'est déroulée avec une efficacité et un sérieux impressionnants. L'installation est non seulement performante, mais aussi esthétiquement très discrète. Aujourd'hui, nous profitons d'un confort thermique idéal, été comme hiver.”
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On-site visit, consumption analysis, detailed cost simulation. Full quote delivered within seven days. If your project is not technically or financially viable, we tell you straight.
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