G1/G2 Technician, EPB Adviser or CERGA Installer: Who Does What When It Comes to Your Heating?

Three professions, three different roles

When it comes to boiler servicing, selling a property, or installing a new gas appliance, you'll often come across acronyms that look similar but refer to entirely different things: approved G1 or G2 technician, EPB (energy performance of buildings) adviser or certifier of type 1 or type 2, and approved CERGA installer. All of these professionals are involved, to varying degrees, in the heating of a Brussels home, but their roles, training and legal obligations are quite distinct.

This confusion comes up regularly among our customers, particularly during a property sale or a boiler replacement, when several documents and certificates are requested at the same time. Here, role by role, is what each of these approvals actually covers.

The approved G1 (and G2) boiler technician: everyday servicing and safety

In Brussels, as elsewhere in the country, the servicing of gas heating systems is governed by regional environmental regulations. In practice, a private individual cannot have their gas boiler serviced by just anyone: the person carrying out the work must hold a gas technician approval, issued after specific training and recognised by the relevant authorities.

What the G1 approval covers

An approved G1 technician is qualified to carry out the periodic servicing of domestic gas heating systems, in other words the individual boilers found in the vast majority of Brussels houses and flats. Their work includes cleaning and checking the combustion components, verifying the tightness of the gas circuit, checking the draught and flue gas evacuation, and measuring combustion emissions. At the end of this service, they issue a periodic inspection certificate, a document that the owner or tenant must be able to present in the event of an inspection or an incident.

This servicing is not just a recommendation: it is a legal obligation, and the exact frequency depends on the type of appliance (a naturally-aspirated or a room-sealed boiler, for example). Your approved heating engineer is best placed to tell you the precise deadline that applies to your system, as the rules evolve and vary from case to case. This regular check is not merely an administrative formality: it allows wear, a leak or poor combustion settings to be detected in time, which could otherwise generate carbon monoxide, a particularly dangerous colourless and odourless gas. It is precisely for this reason that the law requires this check to be carried out by a trained and approved professional, rather than by even the most experienced DIY enthusiast.

What the G2 approval covers

The G2 approval covers higher-output gas heating systems, typically those found in apartment blocks, commercial buildings or certain larger boiler rooms. The principle remains the same — periodic inspection, safety, certificate — but the scope extends to more complex and more powerful equipment, which requires additional technical expertise.

In short: the G1 or G2 technician is your point of contact for everything relating to recurring servicing, the proper functioning and the safety of your existing system.

The EPB adviser, or EPB certifier, type 1 and type 2

The EPB adviser, also known as the EPB certifier, has nothing to do with servicing your boiler. Their job is to assess the energy performance of the building as a whole: insulation, window frames, heating system, hot water production, ventilation, and so on. This results in an EPB certificate, a document required when selling or letting a property in Brussels, which assigns an energy rating to the home (from highly efficient to highly energy-intensive).

Type 1: individual dwellings

The type 1 EPB certifier is approved to draw up the certificate for an individual dwelling: a single-family house, a flat, or a studio. This is the most common situation for a private individual selling or letting their property.

Type 2: other buildings

The type 2 EPB certifier works on more complex or larger buildings: entire apartment blocks, offices, shops, or mixed-use buildings. Their training and approval cover a wider range of calculation methods and building types than type 1.

The EPB adviser relies on existing data (invoices, plans, materials used) as well as an on-site visit, but does not carry out any servicing, repairs or installation work. Their role is purely diagnostic and administrative, in the interest of transparency on the Brussels property market.

The approved CERGA installer: fitting a new gas system

The acronym CERGA refers to an approval system recognised at Belgian level for installers who fit new natural gas heating systems. In practice, when an old boiler is replaced or a new gas appliance is installed, the work must be carried out according to the rules, then inspected and validated by an approved body before it is finally put into service.

An approved CERGA installer is therefore not the same as a G1 technician: the G1 technician services a system that is already in operation, whereas the installer is involved when a new system is fitted, with specific requirements relating to the gas connection, the safety of the pipework, and the overall compliance of the system before it is switched on. This validation step is essential: it ensures that the new installation meets the safety standards in force before gas starts flowing through the pipes.

Why this distinction matters to you

Beyond the administrative jargon, knowing who does what can save you a great deal of hassle:

• If you're looking to have your boiler serviced or a breakdown repaired, you need an approved G1 or G2 technician, not an EPB certifier.
• If you're selling or letting your property in Brussels, you'll need an EPB certificate drawn up by an approved adviser of type 1 (dwelling) or type 2 (other building), in addition to your boiler servicing certificates.
• If you're replacing your boiler with a new gas appliance, the installation will need to be fitted and validated in accordance with the requirements of the CERGA approval, in addition to its subsequent regular servicing by a G1 technician.

These three documents — the servicing certificate, the EPB certificate, and the installation compliance certificate — are, moreover, often requested together during a property transaction or an inspection. Confusing them or overlooking one can delay a sale or, worse, allow a safety issue that should have been detected to go unnoticed.

Who to contact at DPS Chauffagiste

At DPS Chauffagiste, our technicians work as approved professionals for the servicing, repair and periodic inspection of your gas and heating oil systems in Brussels. Our role is to keep your boiler in good working order, to detect signs of wear or poor combustion in good time, and to issue you with the legal certificates you need.

If your project involves a new gas installation requiring CERGA validation, or drawing up an EPB certificate for a sale or letting, we can point you towards the right people and explain, case by case, which document applies to which situation. Don't hesitate to get in touch with us: it's better to ask beforehand than to discover, at the point of a sale or an inspection, that the right certificate is missing.