Boiler maintenance certificate: what each region requires, and how to track the certificates of all your customers

What is a boiler maintenance certificate?

The boiler maintenance certificate (onderhoudsattest / attestation d’entretien) is the document an accredited technician draws up after the compulsory maintenance or the periodic inspection of a central heating system. Each region has its own rules and its own document: in Flanders a cleaning certificate (reinigingsattest) and a combustion certificate (verbrandingsattest), in Brussels the EPB periodic inspection certificate (attest van de EPB-periodieke controle / attestation de contrôle périodique PEB), in Wallonia the periodic inspection certificate (attestation de contrôle périodique).

Which rules apply depends on the region where the boiler is located. If you work in more than one region, pay attention to the accreditation: according to vlaanderen.be, the accreditations of the three regions are only partly equivalent.

Boiler maintenance certificate by region: the rules in one table

What the regions’ official pages state, consulted on 31 October 2026.

Sources: compulsory maintenance of your central heating installation on vlaanderen.be (in Dutch, undated); boiler and hot water heater (19 January 2025) and EPB inspections and maintenance (19 May 2026) on leefmilieu.brussels, the site of Brussels Environment (in Dutch); periodic inspection and in-depth diagnosis on energie.wallonie.be (in French, undated) and articles 10 and 13 of the Walloon Government Order of 29 January 2009 (in French), unofficial consolidation on Wallex, in force since 24 February 2023. Rules change: check the source before you promise a customer anything, and if in doubt, ask the region or your legal adviser.

Central heating boiler maintenance certificate in Flanders

• Output: the maximum output on the boiler’s rating plate. Below 20 kW, maintenance for gas and heating oil is recommended, not compulsory.
• On the certificate: the technician’s name, accreditation number and signature, and at least the details of the model cleaning certificate and the model combustion certificate. Both models are on the vlaanderen.be page.
• Registration: the technician registers each maintenance digitally within the month. It appears in the owner’s digital home file (Woningpas).
• Rental: the tenant gives the owner a copy of the certificates.
• Postponement: at most 3 months, but the next maintenance is still based on the original date.
• Accreditation: always in the technician’s name. A company cannot be accredited.
• Heating audit: since 1 July 2024 no longer compulsory for installations older than 5 years.

Brussels: the EPB periodic inspection certificate

The accredited technician fills in the certificate digitally, and Brussels Environment (Leefmilieu Brussel / Bruxelles Environnement) turns it into an official PDF. If an email address has been entered, the PDF goes automatically to the owner and to a contact person, such as the tenant. The certificate summarises the maintenance, checks the requirements for proper operation and states whether the boiler is compliant. After work on the burner or a move of the boiler, a new inspection is needed. The owner remains responsible for compliance.

Wallonia: the attestation de contrôle périodique

The technician gives the user the certificate, following the model set by the Minister for the Environment, and keeps a duplicate. The tickets from the measuring instruments are stapled to the certificate. The periods run from the first commissioning, and the inspection takes place no later than three months after the due date. If the owner asks for the certificate, the user hands it over without delay. According to energie.wallonie.be, every central heating system also gets an in-depth diagnosis (diagnostic approfondi), following a periodic inspection, by a technician accredited for that purpose.

Boiler maintenance certificates: where it goes wrong with many customers

For one boiler, this is easy to keep track of. For a heating company with hundreds of customers, it goes wrong in five places:

• The due date is on the previous certificate, at the customer’s, and not in your schedule.
• The rule differs from boiler to boiler: gas or heating oil, above or below 20 kW, Flanders or Brussels.
• The technician does not have the right accreditation for that fuel or that region.
• The certificate gets lost in the van or in a personal mailbox.
• The tenant has the maintenance done, the owner asks for the certificate.

Organising maintenance certificates for your customer base

How to build a maintenance plan per type of installation is explained in preventive maintenance. How long to keep invoices and work orders is covered in the retention period for invoices; for the certificates, follow the region’s rule.

Checklist per certificate

• The technician had the accreditation for this fuel and this region.
• The certificate contains what the region requires, with name, accreditation number and signature where these are required.
• In Flanders, the maintenance has been registered within the month.
• The customer has the certificate, and the owner a copy if they ask for it.
• The certificate is with the installation, next to the report of the visit.
• The next due date is in the schedule.

An example: a heating company in Flanders and Brussels

A heating company on the outskirts of Brussels kept track of due dates in a spreadsheet per technician. When it switches over, the planner enters each boiler separately in the register, with its fuel and output.

A rented flat in Ixelles (Elsene) has a gas boiler. The tenant has the maintenance done, so the visit comes round every two years, with an accredited EPB boiler technician. The technician also enters the owner’s email address, so that the PDF from Brussels Environment reaches them. A house in Halle has a 25 kW heating oil boiler: every year a liquid fuel technician comes by, with a cleaning certificate and a combustion certificate. After each visit, the office stores the certificate with the installation, next to the report.

How it works in Digitalnatie Service Suite

• The boilers: in the installation register, you record each boiler with a customer and a site, with, among other things, its brand and model, serial number and installation date. A column shows the next maintenance: on schedule, soon, overdue or not scheduled.
• The due date: in the maintenance contracts screen, you create a contract for a single installation, with a frequency such as annual, or a custom number of days for a different rhythm, and the date of the next visit. Tabs show the visits within the next 30 days and those that are overdue.
• The visit: once a day, Service Suite creates a preventive maintenance intervention for each active contract whose next visit date has been reached, with an activity to schedule it. More on renewing and tracking in tracking maintenance contracts.
• The reminder to the customer: in the automations, the administrator builds a rule on the intervention reminder template. When the appointment is approaching, the rule sends the customer a reminder email.
• The report: in the technician app, the technician fills in the intervention report, takes before and after photos, has the customer sign and signs it themselves. After ending the work, they send the report to the customer as a PDF by email.
• Storing the certificate: in the installation file, the documents tab holds manuals, certificates and photos. A switch decides whether the customer sees the document in their customer portal, next to the reports of their completed interventions. What else is in that file is described in the service history per installation.

Good to know:

• The Service Suite report is your own work order. The accredited technician fills in the official certificate as the region prescribes. You then store it as a document with the installation.
• A completed intervention does not automatically move the installation’s next maintenance date. Missed contract visits are not created afterwards.
• An appointment reminder is only sent once your organisation’s email account is connected and sending emails to customers is allowed. You ask Digitalnatie for that setting.
• In the standard role templates, the administrator and the manager add documents to an installation. The planner cannot.
• After closing, the report is locked in the app. Only the office can still correct it, and the correction is tracked.

Frequently asked questions

Is a boiler maintenance certificate compulsory?

Yes, for the boilers covered by the region’s rules. In Flanders, the obligation applies to gas and heating oil from 20 kW, and to solid fuel. In Brussels and Wallonia, it concerns the periodic inspection, with the certificate the accredited technician draws up afterwards.

How long do I have to keep a boiler maintenance certificate?

In Flanders, you keep at least the last two certificates, according to vlaanderen.be. In Wallonia, the user and the technician keep the last two certificates, according to article 13 of the Order of 29 January 2009. The Brussels pages we consulted do not mention a period.

Does the tenant or the owner have to have the boiler maintained?

In Flanders, the user is responsible, so for a rental the tenant, who gives the owner a copy of the certificates. In Brussels, it is the tenant, unless the lease names someone else; the owner remains responsible for compliance. In Wallonia, the user has the inspection done and gives the certificate to the owner if the owner asks for it.

Can any technician issue a boiler maintenance certificate?

No. In Flanders, the technician needs a personal accreditation for gas (GV) or heating oil (TV); a company cannot itself be accredited. In Brussels, an accreditation as an EPB boiler technician is needed, and in Wallonia an accreditation for gaseous or liquid fuels.

Does Service Suite create the official maintenance certificate?

The Service Suite user guide does not describe an official regional certificate. The technician writes their report in the app, with photos and signatures, and fills in the official certificate as the region prescribes. The office stores that certificate in the installation’s documents and can make it visible in the customer portal.