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Which fuel source ?

Which fuel source best meets your needs ?

This greatly question influences the choice of your equipment : which system to use, the best way of using the energy produced, the work needed to fit the appliance(s), the supply, the cost and the environmental impact.

Your choices are : oil, solid fuels (wood, wood pellets and coal), gas, solar, aerothermics and geothermics.

All these energy systems can work together

All De Dietrich heating systems are designed to be compatible with each other. You can therefore combine gas, oil, wood, heat pump or solar installations, according to your requirements and your objectives in terms of comfort and budget.


Domestic oil has evolved into a clean energy source thanks to changes in the composition of the product and technical progress made in the burner-boiler duo. It is ideal for installations which do not have a mains supply


  • The low fuel consumption of high output oil-fired boilers means that is possible to install small boilers and save considerable amounts of space.
  • The installation only has to undergo maintenance and cleaning once a year.
  • Fuel supply and any adjustments only have to be made once or twice a year.
  • Delivery conditions are simplified by tailor-made storage tanks which can be installed either inside or outside the home.
  • An economical fuel source for central heating systems and the production of domestic hot water.


  • The fluctuating price of oil, as it is a by-product of refinement.
  • Oil is a fossil fuel : like all fossil fuels, burning it releases carbon dioxide into the atmosphere, which is the cause of the greenhouse effect. Howerer the burning efficiency has been greatly improved with new burner technology. The extraction of petrol also diminishes irreplaceable underground stocks.


The term solid fuels includes so-called traditional sources such as wood and coal, but also wood pellets. Wood pellets are a new generation fuel source made from wood chips and sawdust which are compressed to produce a homogenous and compact material.


  • Solid fuels offer a good level of output, a gentle heat, and are most often used for domestic installations.
  • Wood burning and wood pellet boilers can be combined.
  • Logs of wood are one of the cheapest forms of fuel (for example, in France, the annual cost is around 320 euros for a 120m² house).
  • Wood is a 100% natural fuel source.  
  • Wood pellets have a constant level of humidity and grading, which make them an easy-to-use combustion material.
  • Wood pellets can be delivered by tanker and stored inside the house in a tank which can store upto a year's supply of fuel, depending on it's volume.
  • The wood pellets are automatically supplied to the boiler using a conveyer belt installed between the storage tank and the boiler.
  • A year's worth of wood pellets costs around 420 euros for a 120m² house, in France.


  • Wood and coal requires storage space.
  • Coal is a fossil fuel : the by-products of combustion, notably sulphur, are a source of pollution. The mining of coal reduces limited underground sources.


Gas can provide comfortable heating for large areas, and has become popular in a number of homes. 


  • Gas provides a constant room temperature.
  • Gas does not produce dust and is almost odourless.
  • For users who are connected to the mains supply, payment is usually monthly.
  • Gas is also available to homes which are not connected to mains gas, by storing GPL (butane or propane) in tanks which are either above or below ground. For these homes, payment is made when the fuel is delivered, once or twice a year.
  • All gas-fired heating systems are fitted with safety systems.


  • The price of gas can fluctuate over the year. This means that the energy budget of homes which are not on mains gas has to be managed more carefully.
  • Gas heating systems need to be serviced once a year.


Energy emitted by the sun reaches the earth in the form of electromagnetic rays, similar to radioelectric rays but with a different frequency range. Some of this energy is absorbed as the rays pass through the Earth's atmosphere. The quantity of energy carried by the rays is significant and can reach around 1000 W/m². This solar energy, which is free and renewable, can be easly converted into a source of domestic heating.


  • Solar energy produces no greenhouse gas emissions. By choosing solar, you are helping to save the planet.
  • Solar energy equipment requires no storage space inside or outside the house. 
  • Solar energy is free : the only costs come from the initial installation and subsequent maintenance.
  • The new generations of solar installations enable an optimal use of solar energy which means that they can be used even in areas which are not very sunny.
  • It is possible to combine a solar installation with a traditional heating system.


  • The quantity of energy which can be generated depends on weather conditions : when solar energy is inadequate, the use of a back-up system can become necessary.


To use the heat produced by nature , there are two major principles : aerothermics and geothermics. These two principles are used by De Dietrich heat pumps.


Aerothermics involves of using a heat pump to capture the energy in the outside air. An hydraulic circuit feeds either an underfloor heating/cooling system or radiators or fan-convectors.


  • This solution is easy to implement as it does not require a large installation area.
  • It generates no polluting gas emissions.
  • The home can be heated in winter and cooled in summer (reversible heat pump system).


  • The site of the heat pump must be carefully chosen, sheltered from dominant winds.
  • A clear area is required all around the heat pump for connections, installation and maintenance.
Picture Aerothermics


Geothermics captures the heat present in the ground using vertical or horizontal captors, depending on the layout of the land:

  • In horizontal capture, the energy is drawn by a network of captors which are buried at a depth of between 80cm and 120cm. The ground produces energy and the water circulating in this network carries the energy to a heat pump which then transforms it into hot water for heating.
  • The captor is buried in a borehole which can be up to 100m deep. It captures the unlimited energy which is contained in the ground. This energy is then used to heat the home.
  • The water is directly taken from the ground water supply and the heat pump provides a constant temperature for heating your home.


  • An efficient system which generates important energy savings.
  • It is very easy to create a level comfort according to the season.
  • When the ground water is not consumed, it is returned to its source. This means that geothermics is an ecological system of heat production.


  • The initial investments are expensive. Howerver, these expenses are often reduced by tax credits [e.g : in France. Check with your local government].
  • The land surface area required for horizontal capture is significant, around twice the surface area to be heated.
  • A vertical system typically requires adminstrative approval regarding the protection of the water table. Please check with your local authority



Your De Dietrich supplier will advise you about the best choice for your, based on your needs and priorities.

Remember to service your boiler regularly. Having it cleaned and reset once a year results in energy savings of 10% to 15%.