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Practical guides, real costs and installer advice on energy in Western Switzerland.
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I.ON installs heat pump water heaters for homeowners across Western Switzerland. The unit uses the heat of the ambient air to warm your domestic hot water: around 70 % less electricity than an electric water heater. Between CHF 4,000 and 7,000 installed, fitted in a single day, and more profitable still when paired with your solar installation.
How it works
A heat pump water heater proves that efficiency and quiet operation go together. A small built-in heat pump captures the heat of the ambient air in the room where it stands, a cellar, a laundry room, a plant room, and transfers it to the water in the tank. With a typical COP of 3 to 3.5, every kilowatt-hour of electricity consumed produces 3 to 3.5 kWh of heat.
The result: around 70 % less electricity and close to CHF 600 a year saved compared with a conventional electric water heater, and more sustainably than oil or gas. Common capacities run from 200 to 300 litres, enough to cover a household of 2 to 5 people with a single heating cycle a day.
Installation is straightforward: the unit connects to the existing water pipes, without major works. The upfront investment is higher than an electric water heater, between CHF 4,000 and 7,000 installed depending on capacity and configuration, but the system proves particularly profitable over time.
Use cases
Three situations where a heat pump water heater is the most relevant solution, and often the simplest to carry out.
The most common case by far. Several Western Swiss cantons are progressively restricting like-for-like replacement of electric water heaters: Vaud, in particular, requires a renewable alternative at renewal. A heat pump water heater connects to the existing water pipes, without major works, and divides consumption by three.
Saving: around 70 % of the electricity, roughly CHF 600 a year.
Your heat pump heats the house but not the domestic hot water, or its tank is undersized? A dedicated heat pump water heater takes hot water on independently, without calling on the heating circuit through the summer.
The unit draws its heat from the ambient air of the plant room.
Paired with a solar installation, the heat pump water heater runs when your panels are producing. Hot water becomes close to free and your self-consumption rises measurably, with no battery involved.
The hot water tank acts as thermal storage.
Sizing
Indicative benchmarks for a Swiss household. Final sizing is done on site, based on your consumption habits and the room available.
| Profile | Hot water need | Recommended capacity | Note |
|---|---|---|---|
| Two-person household | 80 to 100 litres/day | 200 litres | Covers daily showers and kitchen use with a comfortable margin. |
| Family of 3 to 4 | 120 to 160 litres/day | 250 to 270 litres | The standard for a detached house. A single heating cycle a day is enough. |
| Family of 4 to 5 | 160 to 220 litres/day | 300 litres | Recommended with a bathtub or teenagers. Avoids top-up heating cycles. |
| Paired with solar | Depends on solar output | 300 litres + PV control | Tank deliberately oversized to store the solar surplus as heat. |
Our approach
Number of occupants, consumption habits, condition of the current water heater and of the room (volume, temperature, ventilation). A heat pump water heater needs a room of roughly 20 m³, or ducting to the outside.
Selection of a 200 to 300 litre tank depending on your household, on ambient air or ducted. Every unit we install meets the criteria of the GSP quality label, with a typical COP of 3 to 3.5.
Some cantons and energy suppliers grant subsidies for a heat pump water heater. I.ON handles the entire application with the relevant authorities before work starts.
Removal of the old water heater, connection of the new tank to the existing water pipes, electrical connection. No major works: the job is finished the same evening, hot water included.
Setting the target temperature (50-55 °C), programming the weekly anti-legionella cycle, configuring time slots or solar control. Full explanation of how it works before we leave.
Grants and payback
Between subsidies, tax deduction and running-cost savings, a heat pump water heater is one of the fastest energy investments to pay back.
Some cantons and energy suppliers grant subsidies towards installing a heat pump water heater, particularly when replacing an electric one. I.ON handles the entire application with the relevant authorities.
Replacing an electric water heater with a heat pump water heater is an energy investment deductible from taxable income in most Western Swiss cantons.
Around 70 % less electricity than an electric water heater, in the order of CHF 600 a year for a household. Over the lifetime of the unit, the cumulative saving comfortably exceeds the initial extra cost.
Running on your own solar electricity, domestic hot water becomes almost free. PV control triggers the heating cycle while the panels are producing, with no additional investment in a battery.
Customer reviews
“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.”
Frequently asked
Another question about heat pump water heaters, the subsidies in your canton or lead times in Western Switzerland? Our team replies within 24 hours.
Expect between CHF 4,000 and 7,000 installed, depending on capacity (200 to 300 litres) and configuration (ambient air or ducted, complexity of the connection). Compared with an electric water heater, a heat pump water heater uses around 70 % less electricity, close to CHF 600 saved a year: the initial extra cost is generally paid back in 5 to 8 years.
Replacing an electric hot water tank with a heat pump water heater costs between CHF 4,000 and 7,000 installed, removal of the old unit included, in Geneva as in the other Western Swiss cantons. For a straightforward service (anode check, descaling of the tank), expect CHF 250 to 450 depending on water hardness and access. We work across Geneva, Vaud, Fribourg and Neuchâtel, with a firm quote within 7 days.
Yes. Some cantons and energy suppliers grant subsidies towards installing one, in particular when replacing an electric water heater. Amounts and conditions vary by canton and commune. I.ON handles the entire application with the relevant authorities.
The heat pump water heaters installed by I.ON are among the best performing on the market. They meet the criteria of the Heat Pump Quality Label issued by the Swiss Professional Association for Heat Pumps (GSP), the industry quality benchmark in Switzerland.
Yes, all our heat pump water heaters include an anti-legionella function. It is a second temperature setpoint, higher than the usual 50 to 55 °C: the controller raises the water to between 60 and 65 °C once a week (programmable) to disinfect the tank and eliminate any bacteria forming.
A single day in the vast majority of cases. The unit connects to the existing water pipes, without major works: the old water heater comes out in the morning, the new tank is fitted and connected during the day, hot water is available the same evening.
15 to 20 years with minimal maintenance, comparable to a quality electric water heater. Periodic checks of the protective anode and descaling according to the water hardness in your region extend the life of the tank.
No. The units we install typically emit between 35 and 50 dB(A), the equivalent of a fridge or a modern dishwasher. Installed in a cellar, a laundry room or a plant room, a heat pump water heater is inaudible from the living areas.
A heat pump water heater is a small heat pump dedicated solely to domestic hot water: it heats a 200 to 300 litre tank using ambient air. A full heat pump also heats the whole house through radiators or underfloor heating. If your heating system still works well, a heat pump water heater is the simplest and least expensive renewable step.
More questions? All our answers (lead times, warranties, grants) are in the full FAQ. And to check that we cover your area, browse our service regions in Western Switzerland.
Learn more
Real 2026 heat pump prices by type and by floor area in French-speaking Switzerland. Gross costs, grants, effective net cost calculation. Advice from I.ON Rolle (VD).
Read the articlePompe à chaleurReplacing an oil boiler with a heat pump in French-speaking Switzerland: procedures, costs, grants, timeline. The complete 2026 guide.
Read the article
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