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Boiler

A boiler is a device that produces hot water to heat a given area. A network of pipes and radiators is filled to circulate the heat. This is the most common method in France for heating a home. There are many different types of boiler, all of which have their advantages and disadvantages, and different types of fuel can be used to power them. Although each solution has a different cost and energy performance, they're all designed to heat a home to 19°, based on recommendations from the French environment and energy conservation agency (ADEME).

There are electric, gas, oil and wood-fuelled boilers, as well as combination boilers that use several energy sources. Another decisive factor is the technology used: a boiler can function in a traditional way but also be low-temperature or condensing.

How does a boiler work?

The idea of a boiler is to heat water through combustion (of gas, oil or wood). In an electric boiler, the water is heated by an immersed electrical resistance device or by projecting ions at high speed. The hot water is then circulated by radiators or an underfloor heating.

Boilers and hot water production

A boiler is either single-purpose if it's only designed for heating the home, or is known as a combination or dual-application boiler if also used to provide domestic hot water. If so, it may produce hot water in instantaneous mode or use a buffer tank (micro-accumulation) or an accumulation tank to handle the higher demands of a home's inhabitants. Discover all our products

The different types of boiler

  • Electric boiler
An electric boiler functions simply, requires no fuel and heats water quickly. Although annual servicing is inexpensive, it uses a lot of electricity and is therefore an expensive method of heating. It therefore isn't recommended, except as a backup or for heating small areas. A power management system can nevertheless be used to make savings.
  • Wood-fired boiler
Wood-fired boilers are economical thanks to the low cost of the fuel. They are also eligible for the tax credit in France. What's more, they use a renewable, ecological and high-performance fuel. Although you can choose to use logs, which are an economical solution, you'll need to have a storage space for them and load them into the boiler manually. You'll also need to clean out the ash on a daily basis.

Boilers that use wood pellets are also available. These require small pellets of wood, which are easier to handle than logs and more practical to store in a silo, which can automate the burning of the wood. However, the large volume of ash produced means you'll need to regularly clean the boiler to prevent it from becoming clogged.
  • Oil boiler
Although oil boilers are not so common anymore, they are efficient, particularly if you're heating a large area. Because oil is a polluting fossil fuel, this type of solution is gradually being abandoned, although it might be chosen to replace a similar installation. Your home will also need a cellar for storing the oil. If you install a new model you may be eligible for a tax credit.

Fortunately, new technologies have improved the performance of oil boilers and reduced the pollutant emissions to make this a more ecological solution. Condensing boilers can also capture the heat given off by the combustion fumes to give an improved energy performance (> 100%) and energy savings of up to 30%. However, condensing boilers often mean that you need to line the flue, and the price of this type of fuel often fluctuates.

Another solution is a latest-generation low-temperature boiler, which uses less fuel than the standard devices. On average, this type of installation generates savings of 10% to 15%.
  • Gas boiler
If your home is connected to your local natural gas supply, it's well worth installing a gas boiler. Natural gas is cheaper than electricity or oil and is less polluting than oil. If there's no natural gas supply in your area, you can also install a stand-alone tank. In this case, you'll need to add the price of the installation work and the tank to the cost of use and maintenance. There are two types of gas boiler: low-temperature gas boilers and condensing gas boilers.

Low-temperature gas boilers are now replacing the traditional types and generate savings of 10% to 15% by comparison. They heat your home to a comfortable temperature, can be installed in the floor or on the wall and produce less heat than in the past in order to save energy. The only downside is that this type of boiler isn't eligible for the tax credit in France.

Even more sophisticated, a condensing gas boiler captures heat from the water vapour in the fumes produced. This optimises its energy performance and earns it the 'high energy performance' label. It therefore achieves a high level of comfort while also generating energy savings. Nevertheless, bear in mind that the condensation needs to be vented and a lined flue is required to vent the steam.

All you need to know about the energy transition tax credit

The energy transition tax credit is a French government initiative designed to encourage the installation of high energy performance heating devices, which receive 30% tax relief on the amount of eligible expenses.

To be receive it, you'll need to install an eligible type of boiler in your home, which must be your main residence, and the boiler must be installed by an environmentally-certified ("RGE") professional.

How to choose a boiler

You'll need to assess the pros and cons of each different type of boiler. Bear in mind the constraints of your home: the surface area and requirements, the number of occupants, the current heating system, whether you can install a hot water cylinder, a tank or a wood storage area, the work required to line a flue, etc. Take advantage of the local gas supply if your home is connected and preferably choose a boiler that's eligible for the French tax credit.

Decide which type of boiler you want based on the price, the installation work and maintenance required, its performance and the energy savings it will generate. It's best to get a condensing boiler for maximum comfort at an affordable price, a wood-fired boiler if you want an energy-efficient solution, etc.

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