A gas or oil boiler produces combustion. This combustion generates residues (soot, condensates, carbon monoxide) that accumulate in the heat exchanger and the flue. Without regular cleaning, these deposits degrade the efficiency of the device and increase the risks of CO poisoning. In Brussels, the PEB regulation strictly governs this maintenance, with periodic checks and the power to take the device out of service in case of non-compliance.
PEB Control in Brussels: a regulatory framework stricter than elsewhere in Belgium
The Brussels-Capital Region imposes a mandatory periodic PEB check every two years for all gas boilers and gas water heaters, without power threshold. This obligation stems from a decree by the Government of the Brussels-Capital Region dated June 21, 2018.
See also : Essential Tips for Succeeding and Monetizing Your Blog in 2024
The certified technician who conducts this check does not limit himself to a visual inspection. He measures the combustion efficiency, checks the ventilation of the room, the flue gas evacuation, and the CO/CO₂ levels. If the efficiency falls below the regulatory thresholds or if a safety defect is found, the technician can impose taking the device out of service.
Understanding the importance of boiler maintenance in Brussels allows one to grasp the concrete consequences of a failed PEB check: no heating or hot water until compliance is restored.
See also : Understanding the stakes and impact of digitalization in business today
For oil boilers, a similar check exists with specific requirements for liquid fuels. In all cases, the safety inspection report must be kept and presented upon request, especially in the event of a heating-related incident.
Combustion efficiency and safety: what the technician actually measures
Combustion efficiency is the ratio of the thermal energy transferred to the water in the circuit to the energy contained in the burned fuel. The higher this efficiency, the less the boiler wastes gas or oil to reach the set temperature.
During the check, the technician inserts a probe into the flue. This probe analyzes the composition of the evacuated gases. Three parameters are particularly important:
- The flue gas temperature: an abnormally high temperature indicates fouling of the heat exchanger, as heat is no longer being properly transferred to the water in the system.
- The CO₂ level in the flue gases: it indicates whether the air-fuel mixture is correctly dosed at the burner. A level that is too low reveals an excess of air that cools the combustion.
- The CO (carbon monoxide) level: this is the safety marker. Incomplete combustion produces CO, an odorless and toxic gas. A high level triggers immediate shut-off.
Adjusting the burner after cleaning restores an optimal air-gas mixture. For a boiler that has been dirty for several seasons, the difference in consumption before and after maintenance is significant.
The case of carbon monoxide
CO forms when the flame lacks oxygen. Two main causes in a Brussels residence: a partially obstructed flue and insufficient ventilation of the boiler room. The PEB check verifies these two points. A CO detector in the technical room does not replace maintenance, but it provides an additional safety net between two checks.
Prohibition of gas boilers in new buildings in Brussels: what this changes for existing ones
As of January 1, 2025, permit applications for new or equivalent housing in Brussels must provide for heating systems that operate solely on electricity, renewable energies, or are connected to an efficient heat network. It will no longer be possible to install a new gas boiler in a new home in Brussels.
As of June 1, 2025, this prohibition extends to boilers powered by liquid fuel, including oil, for these same new projects.
For existing homes, no such prohibition applies as of today. The already installed gas or oil boiler can continue to operate, provided that periodic PEB checks are respected. This distinction is fundamental: regular maintenance of your existing installation is not a luxury, it is the legal condition for its continued operation.
Replacement or maintenance: how to decide
If your boiler is over fifteen years old and the technician finds a very degraded combustion efficiency, replacement with a condensing unit may be justified. Condensing boilers recover the latent heat contained in the water vapor from the flue gases, significantly improving overall efficiency.
On the other hand, a well-maintained boiler under ten years old retains satisfactory efficiency. Cleaning the heat exchanger, adjusting the burner, and checking the flue system are sufficient to maintain its performance.
Boiler maintenance in Brussels: responsibility of the tenant or the owner
In the Brussels region, the routine maintenance of the boiler (annual cleaning, minor repairs related to normal wear) is the responsibility of the tenant. The periodic PEB check, as a regulatory obligation related to the compliance of the installation, is generally the responsibility of the owner, unless otherwise stated in the lease.
This division creates a frequent blind spot. The tenant expects the owner to arrange the PEB check. The owner believes that all maintenance falls to the tenant. The result: the boiler is neither checked nor maintained for several years.
The maintenance report and the PEB certificate must be kept by both parties. In the event of an incident (fire, CO poisoning, water damage related to heating), the insurer will request these documents. The absence of a valid PEB certificate may jeopardize compensation.
The simplest solution remains to schedule the intervention of a certified technician before the heating season, between September and October. Intervention times significantly lengthen as soon as the first drops in temperature occur, and a breakdown discovered in the middle of winter requires finding a heating technician urgently, with the additional costs that this entails.