Up to €2,500 in grants
Which water heater should you choose in Luxembourg in 2026: price, running cost and grants?
In Luxembourg, an electric water heater costs €800 to €1,800 installed but about €1,100 to €1,250 of electricity a year for four people; a heat pump water heater costs €3,000 to €7,000 and uses about three times less. Only solar thermal receives a Klimabonus, of €2,500. Here are the prices, running costs and the right choice for your home.
- Installed price: electric €800 to €1,800, gas €1,300 to €3,700, heat pump €3,000 to €7,000, solar €6,000 to €10,000
- Yearly cost for 4 people: about €1,100 to €1,250 electric, €500 to €700 gas, €350 to €480 heat pump
- Saving of a heat pump water heater against electric: about €700 to €800 a year, extra cost recovered in 3 to 7 years
- Klimabonus: €2,500 for a solar water heater in an existing building; nothing for electric, gas or heat pump models
- Volume: 150 to 200 litres for 4 people with electric, 200 to 300 litres with a heat pump or solar
- 3% VAT in a main residence 10 years or older, in practice for works of at least €3,000 excl. VAT
Types of water heater in Luxembourg compared
Four families of water heater share the Luxembourg market: electric, the cheapest to buy and the most expensive to run; gas, tied to the grid; the heat pump water heater, a small heat pump; and solar, the only one subsidised.
| Type | How it works | Installed price | Yearly cost, 4 people | Grant |
|---|---|---|---|---|
| Electric storage (tank) | An element heats a 50 to 300-litre tank | €800 – 1,800 | ≈ €1,100 – 1,250 | None |
| Electric instantaneous | Heats water as it flows, no storage; 18 to 27 kW three-phase for a shower | Within the electric range, plus an upgraded power supply | Slightly less than a tank (no storage losses) | None |
| Gas (instantaneous or storage) | Natural-gas burner, often linked to the boiler | €1,300 – 3,700 | ≈ €500 – 700 | None |
| Heat pump water heater | A small heat pump takes heat from the air | €3,000 – 7,000 | ≈ €350 – 480 | No Klimabonus |
| Solar thermal | Roof collectors, electric or boiler back-up | €6,000 – 10,000 | ≈ €400 – 500 with electric back-up | Klimabonus €2,500 |
A household of 4 using 200 litres of hot water at 55 °C a day, i.e. about 3,800 kWh of useful heat a year, plus tank losses. Electricity €0.24 to €0.28/kWh, gas €0.10 to €0.13/kWh: market orders of magnitude in September 2026, to be replaced with your own tariffs. Installed prices: renov.lu survey of installers in the Grand Duchy.
Running cost: the criterion that decides
Over the life of a water heater, the energy bill makes the difference, not the purchase price: an electric model uses about 4,500 kWh a year for four people, a heat pump water heater three times less.
An electric tank turns 1 kWh of electricity into 1 kWh of heat, plus tank losses. A heat pump water heater returns 2.5 to 3 over the year, and a solar system covers about 60% of needs, leaving only the back-up to pay. Over 15 years, the gap between an electric and a heat pump water heater therefore exceeds €10,000 for a family of four, more than the difference in purchase price. For a single-person household, which uses three to four times less hot water, electric remains a defensible choice.
Heat pump water heaters: the best compromise
A heat pump water heater combines a tank with a small heat pump that takes heat from the air of a cellar, a garage or outdoors. It costs €3,000 to €7,000 installed and saves about €700 to €800 a year against an electric tank for four people.
It works all year round without a well-oriented roof, but an ambient-air model needs a room of at least 20 m³, ideally unheated. It gets no Klimabonus. How it works, models and payback: the heat pump water heater guide.
Solar water heaters in Luxembourg
A solar water heater covers about 60% of annual hot-water needs in Luxembourg: nearly everything from May to September, 30 to 50% from October to April, with an electric back-up or the boiler doing the rest. It costs €6,000 to €10,000 installed for a family of 3 to 5. Prices, real coverage and maintenance: our solar water heater guide.
It is the only subsidised water heater: the Klimabonus pays €2,500 for a solar hot-water system in an existing building, provided the invoice is issued at least 10 years after the building permit, with Solar Keymark-certified collectors and a heat meter. In pure euros, a heat pump water heater often wins; solar takes the lead with a south-facing roof and high demand.
What water heater volume for your household?
For an electric water heater, allow about 50 litres per person: 150 to 200 litres for four people. A heat pump or solar model should be larger, 200 to 300 litres for four, because it reheats more slowly or stores the heat of sunny days.
| Household | Electric | Heat pump or solar |
|---|---|---|
| 1 person | 50 – 75 litres | 100 – 150 litres |
| 2 people | 75 – 100 litres | 150 – 200 litres |
| 3 people | 100 – 150 litres | 200 – 250 litres |
| 4 people | 150 – 200 litres | 200 – 300 litres |
| 5 people or more | 200 – 300 litres | 300 – 400 litres |
A tank that is too small runs out of hot water in the evening; one that is too large heats water for nothing and increases losses. Go larger if the household often takes baths. If your water is very hard, a water softener also protects the tank and its heating element.
Prices, VAT and grants for a water heater in Luxembourg
An installed water heater costs from €800 for a small electric tank to €10,000 for a solar system. The Klimabonus only covers solar thermal, and 3% VAT in practice only applies to projects of at least €3,000 excluding VAT.
- Klimabonus: €2,500 for a solar water heater in an existing house (€2,000 per home in apartment buildings, up to €14,000). Heat pump water heaters, electric and gas models are not on the list of subsidised installations.
- VAT: 3% instead of 17% for an installation supplied and fitted by a company in a main residence at least 10 years old. Direct application requires a quote of at least €3,000 excluding VAT and AED approval before the works: a stand-alone tank replacement is therefore usually invoiced at 17%. Details: 3% VAT on renovation work.
- With a heat pump: hot water produced by an air-to-water heating heat pump is part of the installation covered by the heat pump Klimabonus. See heat pumps and domestic hot water.
Which water heater for your home?
The right water heater depends first on your heating: if you switch to an air-to-water heat pump, it can produce your hot water; otherwise, a heat pump water heater is the best compromise for most houses in Luxembourg. Heating options are compared in our guide to heating in Luxembourg.
| Situation | Recommended choice |
|---|---|
| House switching to an air-to-water heat pump | Cylinder connected to the heat pump, no separate water heater |
| House keeping its boiler, cellar or garage of 20 m³ | Ambient-air heat pump water heater |
| South-facing roof, large family | Solar thermal, subsidised with €2,500 |
| Flat with no utility room | Electric, or an outdoor-air heat pump model if the co-ownership allows it |
| Studio, one person | Small electric tank: the extra cost of a heat pump model will not pay back |
Have your water heater fitted
A heating engineer checks the usable volume, the location, drainage and the electrical connection before quoting. Describe your project: heating engineers established in Luxembourg reply within 48 hours, free and without obligation.
An installed price for your water heater
Electric, heat pump or solar: get quotes from 3 heating engineers established in Luxembourg.
Frequently asked questions about water heaters in Luxembourg
Which water heater is cheapest to run in Luxembourg?
For four people, the heat pump water heater is the cheapest to run, at about €350 to €480 of electricity a year, followed by solar with electric back-up (€400 to €500) and gas (€500 to €700). The electric storage tank is the most expensive, about €1,100 to €1,250 a year. These figures assume 200 litres of hot water a day and electricity at €0.24-0.28/kWh.
What water heater volume for a family of four?
For an electric water heater, 150 to 200 litres are enough for four people. For a heat pump or solar model, choose 200 to 300 litres, as they reheat more slowly or store the sun’s heat. If the household often takes baths, go for the upper range; a tank that is too large, however, increases heat losses.
Instantaneous or storage electric water heater: which should I choose?
A storage water heater suits most homes: it is easy to connect and supplies hot water for several uses at once. An instantaneous heater avoids storage losses and takes up little space, but it needs 18 to 27 kW three-phase to supply a shower, and therefore an upgraded electrical connection. It makes most sense for a distant tap or a small flat.
What grants are there to replace a water heater in Luxembourg?
Only the solar water heater receives a Klimabonus: €2,500 in an existing house, subject to certified collectors and a heat meter. Heat pump, electric and gas water heaters get no grant. 3% VAT applies in a main residence at least 10 years old, but in practice only for works of at least €3,000 excluding VAT, with AED approval requested before the works.
How long does an electric water heater last?
An electric water heater usually lasts 10 to 15 years, a heat pump water heater 15 to 20 years and solar collectors 20 to 25 years. Hard water shortens the life of heating elements: an anode checked every two years and regular descaling extend the tank’s life. Beyond 12 years, if the tank leaks or the element has already been changed, replacing often costs less than repairing.
Do I need a separate water heater when I install a heat pump?
Not with an air-to-water heat pump: it also produces hot water through a built-in or connected 200 to 300-litre cylinder, and the old water heater can be removed. A separate water heater remains useful if the heat pump is air-to-air, which does not produce hot water, or if you keep your boiler for heating: a heat pump water heater is then the best choice.