Frequently asked questions (FAQ)

Since 1966, Belgium has imported natural gas from the Netherlands. The Groningen (Slochteren) field has provided major reserves of so-called ‘lean’ gas. The Netherlands is so close to our country, the advantage of economic stability. In short, importing gas from the Netherlands was an excellent option for Belgium.

In the late 1970s, due to a significant increase in consumption, our country began to import extra gas, mainly from Norway, the United Kingdom, Qatar and Russia. The composition of the gas extracted from these fields is different from that in the Netherlands. It is called ‘rich gas’ because it contains more energy on a volume basis. 

Natural gas has a different composition, depending on its origin. In the Dutch gas field, the energy value of the gas is around 15% lower than the gas from other fields. In other words, 15% more gas is required for heating or cooking. This is why this gas is also known as ‘low-calorific gas’, ‘L-gas’ or ‘lean gas’. Natural gas from other regions in the world is called ‘high-calorific gas’, ‘H-gas’ or ‘rich gas’. 

The Netherlands has decided to gradually reduce its gas exports from Groningen (Slochteren). Its gas exports to Belgium and other countries will end by 2030. If Belgium is to ensure its energy security in gas, it must gradually replace the lean gas from the Netherlands with rich gas sourced from other regions in the world. This change will mean adapting the distribution network so that all consumers can use rich gas in 2030. 

In 2017, around half of Belgium’s gas consumers already use rich gas.

No, we have already seen conversions in the past. In 1966, we switched from town gas to natural gas. Since 1978, several of our country’s regions have made the conversion to rich gas: East Flanders, West Flanders, Hainaut and much of the province of Liège Province. As a result, about half of Belgium’s gas consumers are already using rich gas.

The Netherlands is gradually reducing its gas exports from Groningen and aims to halt them completely by the end of 2030. Region by region, we will convert from lean gas to rich gas, in order to reduce the consumption of Dutch gas. By 2030, we will no longer use it at all. An indicative timetable shows the conversion periods for the municipalities.

You can check on this site if your municipality is affected, partially affected or not affected by the conversion: simply enter your postcode.  For further details on your personal situation, see the website of your distribution network operator and/or your Region.

In Belgium, approximately 1.6 million consumers were involved in 2017. The conversion could therefore not be carried out in one go. Operations started in 2018 and continue until 2024. Every year, a number of municipalities are therefore converted during summer, when consumption is lower. An indicative timetable has been drawn up for this purpose.

You can check on this site if your municipality is affected, partially affected or not affected by the conversion: simply enter your postcode. For further details on your personal situation, see the website of your distribution network operator and/or your region.

The conversion timetable was drawn up on the basis of the consumption and the structure of Belgium’s gas network. It also takes into account the supply of all gas customers and cost optimisation. 

The following factors were taken into consideration:

• a conversion from the south, moving up to the Dutch border;
• the organisation of and possibilities for the gas transportation network;
• maximum reutilisation of existing pipelines;
• the optimisation of the work to be carried out on the consumers' premises.

Consequently, since not all the country can be converted at once, gas consumers have been divided into geographic zones. Each time, they will be prepared for simultaneous conversion and the conversion from lean gas to rich gas will happen on the same day.

The current timetable is in theory definitive. However, we prefer to say that it is indicative because it could still be modified, due to unforseeable factors such as technical constraints, new decisions by the Dutch government or other external factors (such as the coronavirus pandemic, for example).

Some 1.6 million private customers and businesses in Brussels and the provinces of Antwerp, Limburg, Flemish Brabant, Walloon Brabant, Liège, Hainaut and Namur use Dutch gas and will convert to rich gas. 

However, becuase of the large number of consumers, this cannot happen in one go. Conversio operations started in 2018 and will continue until 2024. Each year, a number of municipalities are therefore converted during the summer, when consumption is at its lowest. An indicative timetable has been drawn up to this end.

You can check on this site if your municipality is affected, partially affected or not affected by the conversion: simply enter your postcode. For further details on your personal situation, see the website of your distribution network operator and/or your region.

Gas suppliers decide where they purchase the gas used to supply their customers. Nowadays, these countries are mainly Norway, the United Kingdom, Qatar and Russia. By using the Zeebrugge LNG terminal, suppliers may also buy gas from the Caspian Sea region and North Africa or from any other country. 

There are many gas fields in the world, whose gas has is rich and has about the same composition as the gas that will be consumed everywhere in Belgium from 2025. This is why it is easy to change the source of supply to into rich gas. A new conversion is therefore highly unlikely.

No, the conversion will not affect gas in bottles (propane or butane), nor gases used for vehicles (LPG, CNG). 

LPG (Liquid Petroleum Gas), propane gas and butane gas are produced from oil. So they are not natural gases.

CNG (Compressed Natural Gas) however is the same natural gas that we use for heating or cooking. Vehicles running on CNG can run either on lean gas or rich gas and therefore do not need to be adapted. Likewise, nothing needs to be done for individual domestic appliances used for filling CNG vehicles (slow fill). Only fuel service stations delivering CNG will have to be adapted to take into account the conversion to rich gas. 

The distribution network operator is responsible for the technical installation of your gas supply: the valves, pipes and everything up to and including your meter. It is responsible for building, maintaining and managing the gas distribution networks as well as the distribution of gas to consumers connected to their network. Its role and responsibility are limited to the meter. Who is your distribution network operator? It depends on the region where you live.

The gas supplier purchases large quantities of gas on the market (wholesale) and resells the gas to retail consumers: private customers and businesses. The natural gas supplier is responsible for the service’s administration and billing. So this supplier purchases the rich gas replacing the lean gas and bills you for your gas, based on consumption data provided by your distribution network operator. A gas consumer can choose their gas supplier. 

Enter your postcode on this site to see your distribution network operator. 

You can find your gas supplier’s contact details on your gas bill. 

For private customers, appliances running on natural gas are typically boilers, small and large water heaters, cookers and cooking hobs, stoves, convector heaters and decorative fireplaces. 

In businesses, appliances running on gas are typically:

• heating appliances: boilers, air heating units, air heaters, infrared radiant heaters (dark and light), heat pumps;
• cogeneration appliances for producing heat and electricity;
• appliances producing hot water;
• professional cooking appliances: hobs, deep-fryers, grills, woks, rotisseries, etc.;
• appliances for washing (washing machines) or for drying (dryers);
• appliances for thermal industrial processes.

You must have all these appliances inspected, to be certain they run properly and in complete safety after the conversion.

The conversion to rich gas only affects natural gas, and not appliances running on gases in bottles (propane or butane), nor vehicles that run on gas (LPG, CNG).

Make sure all your gas appliances are inspected by an authorised technician, as soon as your distribution network operator and/or your gas supplier have notified you. It is your responsibility to have this inspection done, to ensure that they run properly and in complete safety after the conversion.  

The inspection must be done before the actual conversion. If you ask for this inspection in good time, you can combine it with the next compulsory periodic inspection of your boiler.

The authorised technician will check the compatibility of your appliances with rich gas, and may adapt your appliances. He may also have to carry out two adaptations: an intermediate adaptation before the conversion and a definitive adaptation after the conversion.

Ask your technician for a visit report indicating which of your gas appliances have been inspected and any adaptations made. This will provide you with documentary evidence of the technician’s visit and any work carried out. 

No, necessary low-calorific gas was and will be produced using conversion machines (production of pseudo-L gas). In other words, high-calorific gas is made compatible with the low-calorific gas grid by adding nitrogen. 

No, low-calorific gas users who have not yet been converted can continue to consume natural gas without any problems. The conversion is announced in good time by the distribution system operator (see FAQ above - www.gaschanges.be).

As soon as you are notified by your distribution network operator and/or your gas supplier, be sure to have all your gas appliances inspected by an authorised technician. This will guarantee that your appliances continue to run properly and in complete safety after the conversion.

If you ask for this inspection in good time, you can combine it with the next compulsory periodic inspection of your boiler.

If you don’t get your gas appliances inspected, this could pose a risk after the conversion. Indeed, your appliance may not run at optimum efficiency, for example because it produces more CO (carbon monoxide), it consumes more gas or it wears out faster. A gas appliance in poor working order will cost more, is bad for the environment and might be harmful to your health and/or that of your colleagues in some circumstances. Remember that, in general, rooms containing a gas appliance must be sufficiently ventilated. It is important to comply with the various safety standards in this field.

Not all gas appliances are adapted to run on rich gas, especially those made before 1978 and some foreign appliances.

Consequently it is essential to have all your gas appliances inspected by an authorised technician. This technician will also be able to check whether all the installation environment conditions are met to ensure your safety and that of your colleagues. This means you can then sleep soundly.

Ask your technician for a visit report indicating which of your gas appliances have been inspected and any adaptations made. This will provide you with documentary evidence of the technician’s visit and any work carried out.

No. After the conversion, your street will no longer be supplied with lean gas. Your network will only distribute rich gas.

No, rich gas and lean gas produce the same amount of CO (carbon monoxide), if your gas appliance is correctly adapted. That is one reason why you must have all your gas appliances inspected.

Remember that, in general, rooms containing gas appliances must be sufficiently ventilated. It is important to comply with the various safety standards in this field. 

The cost of the inspection and any adaptation of your domestic appliances will depend on the number and type of appliances that have to be inspected, as well as the fees of your authorised technician. We estimate that in most cases it will cost you anything between € 0 and € 150 for 1 to 3 domestic appliances (non-contractual estimation - September 2017). This estimation is based on monitoring of prices charged on the market and takes into account a broad range of applicable technical factors. For large or professional appliances, you should contact your authorised technician.

If you ask for this inspection in good time, you can combine it with the next compulsory periodic inspection of your boiler.

This will save you from calling out your technician especially and from paying out twice for his travel costs. 

You should ask for several price offers and make the most of competition.

Yes, it’s possible.

Gas appliances produced from 1978 onwards are generally compatible with rich gas, but sometimes they must be adapted to run properly and in complete safety.

Gas appliances made before 1978 will generally not be compatible, which means they will likely have to be replaced.

Gas appliances purchased in other countries likely do not meet the legal standards in force in Belgium. They must be replaced or made compatible with Belgian legislation if technically possible, provided the age of the appliance still enables this and provided the operational safety can be guaranteed. Only the manufacturer can provide professional advice on this.

In every case, it is essential to have all your gas appliances inspected by an authorised technician, to ensure they continue to run properly and in complete safety after the conversion.

Most gas appliances installed before 1978 are not compatible with rich gas, so they will probably have to be replaced. 

Have all your gas appliances inspected by an authorised technician, to ensure they continue to run properly and in complete safety after the conversion.

Most gas appliances sold in Belgium since 1978 are compatible with lean gas and rich gas. Some of them were specifically adapted to run on lean gas. If so, they will have to be adapted again, in order to run on rich gas. Your authorised technician can do this adaptation when the time is right, if necessary. He may also be called on to carry out two adaptations: an intermediate adaptation before the conversion and a definitive adaptation after the conversion.

Gas appliances purchased in other countries likely do not meet the legal standards in force in Belgium. They must be replaced or made compatible with Belgian legislation if technically possible, provided the age of the appliance still enables this and provided the operational safety can be guaranteed. Only the manufacturer can provide professional advice on this.

In every case, have all your gas appliances inspected by an authorised technician as soon as your gas supplier and/or your distribution network operator have notified you. This means you can be sure that they will continue to run properly and in complete safety after the conversion. 

Please note that only gas appliances meeting Belgian standards can legally be installed in our country. Gas appliances purchased in other countries likely do not meet the legal standards in force in Belgium. They must be replaced or made compatible with Belgian legislation if technically possible, provided the age of the appliance still enables this and provided the operational safety can be guaranteed. Only the manufacturer can provide professional advice on this.

In every case, have all your gas appliances inspected by an authorised technician, to ensure that they will continue to run properly and in complete safety after the conversion. 

You can’t check this yourself! Even if your appliance is compatible with rich gas, it may have been adapted to run specifically on lean gas. This adaptation can only be seen by measuring the smoke composition, which explains why this inspection must be done by an authorised technician. 

If your appliance has been adapted to run on lean gas, it must be adapted again before your conversion to rich gas. This is for health reasons, to protect the environment and to ensure it will run smoothly after the conversion.

In every case, have all your gas appliances inspected by an authorised technician as soon as your gas supplier and/or your distribution network operator have notified you. This means you can be sure that they will continue to run properly and in complete safety after the conversion. 

The conversion to rich gas won’t make any difference to your gas bill. The calculation on your bill will look different, but you will pay the same total as before.

For the annual reading of your meter by your distribution network operator, you should check your gas meter to read the gas volume you have consumed: this is the number of cubic metres. Your distribution network operator will then transform this gas volume into kWh by using a maths formula. You therefore pay for the total volume of energy that you have consumed, expressed as kWh, and not the number of cubic metres.

Low-calorific gas (lean gas) and high-calorific gas (rich gas) have a different amount of energy per cubic metre. High-calorific gas has more energy than low-calorific gas, which explains why it is more expensive. However, you will consume fewer cubic metres of rich gas.

To ensure that you ultimately pay the same energy cost per kWh, the distribution network operator uses different formulas for converting cubic metres into kWh, depending on whether it’s high-calorific gas or low-calorific gas. If you consume exactly the same amount of energy, your bill will not change at all.

As things stand today, no: you are responsible for the expenses.

But it’s worth noting that there are some benefits when you buy a new gas appliance. When you replace your appliance made before 1978 with a new one, your consumption should fall by up to 25%. Some Belgian regions also offer a grant for the purchase of a new appliance. You can find more information on this topic on the websites of the Flemish, Brussels-Capital and Walloon Regions. 

Your gas appliances must be inspected by an authorised technician, which means someone who is qualified in this field. There are three types of authorised technician:

• a technician certified by your Region to carry out a compulsory periodic inspection of boilers: a GI or GII technician;
• a technician from your appliance’s manufacturer;
• a technician from the official distributor designated by the manufacturer of your appliance brand.

You can consult on this site the list of technicians who are certified by your Region for the compulsory periodic inspection of boilers: simply enter your postcode.

Your gas appliances must be inspected by an authorised technician, which means someone qualified to do so. There are three types of authorised technician:

• a technician certified by your Region to carry out a compulsory periodic inspection of your boilers: a GI or GII technician;
• a technician from your appliance’s manufacturer;
• a technician from the official distributor designated by the manufacturer of your appliance brand.

It’s an open market. So we won’t make any recommendations about which technician you should choose.

You can consult this site below to see the list of GI or GII technicians who are certified by your Region for the compulsory periodic inspection of boilers. Enter your postcode to see if your municipality is affected by the conversion.

No, your meter does not have to be adapted. But in some cases, an technician from your distribution network operator will have to adapt the pressure regulator (limiter) near your gas meter. This adaptation is free of charge. Your network operator will do this adaptation. This work is essential for safety reasons. You are therefore required to allow your distribution network operator to access your meter.

No technicians will visit Brussels and much of the Antwerp conurbation, because these areas don’t have pressure regulators. This means nothing needs to be adapted.

In order to recognise a technician from your distribution network operator, check the distribution network operator’s website.

Please note that industrial users provided with medium pressure by their gas supplier must have any low pressure equipment checked and, where necessary, have the pressure regulator adapted. This work will be charged to them.

The pressure regulator for your home/building must be adapted to rich gas before the conversion. If not, this could pose risks. This adaptation will be done by your distribution network operator, so it will not result in any expenses on your gas bill.

You are legally obliged to allow your distribution network operator to access your meter. If your operator cannot adapt your pressure regulator, it may cut off your gas supply, for your own safety.

The owner is responsible for checking that all gas appliances are compatible with rich gas and for any adaptation of those appliances.

The landlord of the rented residence/building must pay the costs for inspecting the gas appliances owned by the landlord, plus any adaptation of those appliances.

The tenant must pay the costs for inspecting and any adaptation of the gas appliances that they own. Where necessary the tenant must also give access to their residence/building by their landlord’s authorised technician.

However the tenancy contract may include a clause that makes the tenant responsible for any inspection and adaptation of appliances provided by the landlord.

Tenants are recommended to notify their landlords of the conversion, and of the obligation on the landlords to carry out an inspection and to make any necessary adaptations to their gas appliances in the residence/buildings they own. That’s because the distribution network operator and/or the gas supplier will notify the tenant about the date of the conversion to rich gas. It is therefore the tenants’ responsibility to notify their landlord.

The appliances themselves must be inspected and where necessary adapted. If your apartment building has a central boiler, it will have to be inspected by an authorised technician, appointed by the co-owners association or the managing agent, to be charged to all the owners. However, if for example each apartment is fitted with an individual boiler, they will all have to be inspected, one after another.

To know how to recognise a technician from your distribution network operator, check the operator’s website.

There are three types of technicians authorised to inspect gas appliances for the conversion:

• technicians certified by one of Belgium’s three Regions, for the compulsory periodic inspection of boilers: GI or GII technicians;
• technicians from the manufacturers of gas appliances;
• technicians from the official distributors designated by the manufacturers of gas appliances.

If you have customers who live in a municipality that is converting to rich gas, all their gas appliances must be inspected and, where necessary, adapted before the conversion.

Some gas appliances are not compatible with rich gas.

Gas appliances produced from 1978 onwards are generally compatible with rich gas, but sometimes they must be adapted to run properly and in complete safety.

Gas appliances made before 1978 will generally not be compatible, which means they will likely have to be replaced.

Gas appliances purchased in other countries likely do not meet the legal standards in force in Belgium. They must be replaced or made compatible with Belgian legislation if technically possible, provided the age of the appliance still enables this and provided the operational safety can be guaranteed. Only the manufacturer can provide professional advice on this.

If you have any doubts about the compatibility of a gas appliance, don’t hesitate to contact gas.be or the manufacturer of the appliance in question. You can also check the conversion website for authorised technicians  for further information.

The inspection must be done before the actual conversion of your customer and after your customer has received a message from their distribution network operator and/or gas supplier, notifying them of the upcoming conversion. 

You should try to combine this inspection with the next compulsory periodic inspection of the customer’s boiler. During this inspection, you may be called on to carry out a new adaptation of some gas appliances. Sometimes, you may also be called on to carry out two adaptations: an intermediate adaptation before the conversion and definitive adaptation after the conversion.

Your customers will receive in good time a message from their distribution network operator and/or gas supplier. However, you should also inform them about this yourself. To that end, check the indicative timetable for conversion on the website of your customers’ distribution network operators.

The inspection must be done before the actual conversion of your customer. You should try to combine this inspection with the next compulsory periodic inspection of the customer’s boiler. During this inspection, you may be called on to carry out a new adaptation for some appliances. Sometimes, you may also be called on have to carry out two adaptations: an intermediate adaptation before the conversion and a definitive adaptation after the conversion.

Your customer will receive in good time a message from their distribution network operator and/or gas supplier, notifying the customer of their upcoming conversion. However, you should also inform them about this yourself. To that end, check the indicative timetable for conversion on the website of your customer’s distribution network operators.

Don’t hesitate to check the conversion website for authorised technicians, provided by the gas.be federation.

The site includes notably industry codes of conduct drafted in collaboration with the ATTB, the Belgian association of boiler and burner manufacturers, and recommended by Bouwunie Installateurs and ICS, the installers federations. It also includes detailed information on the technical specifications, and standard templates for your visit reports and your letters. Moreover, gas.be will also organise information sessions for the technicians.

Your customers will receive a message from their distribution network operator and/or their gas supplier, long before their conversion. However, you can also notify your customers about this. On the conversion website for authorised technicians, you will find a letter template that you can use for this.

If your customers’ gas appliances are not inspected, this might pose a risk after the conversion. The appliances may not run properly well, for example because they are producing more CO (carbon monoxide), are consuming more gas or are wearing out faster. A gas appliance in poor working order will cost more, is bad for the environment and might be harmful to the health of its user.

Don’t hesitate to tell your customers about this!

Remind them that, in general, rooms containing gas appliances must be sufficiently ventilated. It is important to comply with the various safety standards in this field: this is something you can check.

Some gas appliances are not compatible with rich gas.

Gas appliances produced from 1978 onwards are generally compatible with rich gas, but sometimes they must be adapted to run properly and in complete safety.

Gas appliances made before 1978 will generally not be compatible, which means they will likely have to be replaced.

Gas appliances purchased in other countries likely do not meet the legal standards in force in Belgium. They must be replaced or made compatible with Belgian legislation if technically possible, provided the age of the appliance still enables this and provided the operational safety can be guaranteed. Only the manufacturer can provide professional advice on this.

If you have doubts about the compatibility of a gas appliance, don’t hesitate to contact gas.be or the manufacturer of the appliance in question. You can also check the conversion website for authorised technicians for further information.

A special conversion website for authorised technicians has created for you by gas.be.