EN 303-4:1999
(Main)Heating boilers - Part 4: Heating boilers with forced draught burners - Special requirements for boilers with forced draught oil burners with outputs up to 70 kW and a maximum operating pressure of 3 bar - Terminology, special requirements, testing and marking
General Information
- Abstract
This standard is applicable to heating boilers with forced draught oil burners up to a nominal heat output of 70 kW. They are operated, either with negative pressure (natural draught boiler) or with positive pressure (pressurised boiler) in the combustion chamber, in accordance with the boiler manufacturer's instructions. This standard specifies the necessary terminology, the requirements on the materials and testing of them, and marking requirements for heating boilers.
- Status
- Published
- Publication Date
- 19-Jan-1999
- Technical Committee
- CEN/TC 57 - Central heating boilers
- Drafting Committee
- CEN/TC 57 - Central heating boilers
- Current Stage
- 9060 - Closure of 2 Year Review Enquiry - Review Enquiry
- Start Date
- 04-Jun-2019
- Completion Date
- 04-Jun-2019
Overview
EN 303-4:1999 (CEN) specifies requirements for heating boilers with forced draught oil burners with a nominal heat output up to 70 kW and a maximum operating pressure of 3 bar. The standard covers boilers operated with either negative pressure (natural draught) or positive pressure (pressurised) in the combustion chamber, following the boiler manufacturer's instructions. EN 303-4 defines required terminology, material and component requirements, testing and marking rules to ensure safe, consistent performance for small oil-fired central heating boilers.
Key Topics
- Scope and definitions: Clear terminology for forced draught oil burners and related boiler components to ensure consistent interpretation across manufacturers, laboratories and regulators.
- Material requirements: General provisions on suitable materials and component quality to meet durability and safety expectations for boilers up to 70 kW.
- Testing: Specification of testing principles and acceptance criteria for components and completed boilers (material/assembly tests rather than specific procedural details included in the scope).
- Operating conditions: Requirements for boilers operating at up to 3 bar maximum pressure, and for both negative and positive combustion-chamber pressures as per manufacturer instructions.
- Marking and documentation: Mandatory marking and traceability information to be provided on boilers, supporting installation, maintenance and regulatory compliance.
- Terminology harmonization: Ensures uniform language across product literature, technical specifications and conformity assessments.
Applications
EN 303-4:1999 is practical for anyone involved in the design, manufacture, supply, testing, installation or regulation of small oil-fired heating boilers:
- Boiler manufacturers: Use the standard to design and document forced draught oil-fired boilers up to 70 kW.
- Testing laboratories: Reference the standard for material and product-level conformity checks and reporting.
- Installers and HVAC contractors: Use marking and documentation requirements for correct installation and commissioning.
- Specifiers and building engineers: Ensure selected boilers meet recognized technical and safety benchmarks for central heating systems.
- Regulators and procurers: Apply the standard as part of procurement specifications or conformity assessment schemes.
Related standards
- Other parts of the EN 303 series address different boiler types, capacities and test methods; consult the series for boilers outside the 70 kW / 3 bar scope.
- National or sector-specific standards may reference EN 303-4 for harmonized terminology and testing criteria.
EN 303-4:1999 helps ensure safe, reliable and well-documented oil-fired heating boilers with forced draught burners, improving product consistency and supporting compliance across the heating industry.
Relations
- Effective Date
- 25-Aug-2026
- Effective Date
- 25-Aug-2026
- Effective Date
- 25-Aug-2026
- Effective Date
- 25-Aug-2026
- Effective Date
- 25-Aug-2026
- Effective Date
- 25-Aug-2026
- Effective Date
- 25-Aug-2026
- Effective Date
- 25-Aug-2026
- Effective Date
- 25-Aug-2026
- Effective Date
- 25-Aug-2026
- Effective Date
- 07-Jul-2026
- Effective Date
- 09-Feb-2026
- Effective Date
- 09-Feb-2026
- Effective Date
- 09-Feb-2026
- Effective Date
- 28-Jan-2026
Get Certified
Connect with accredited certification bodies for this standard
DIBt (Deutsches Institut für Bautechnik)
German Institute for Building Technology.
DIN CERTCO
DIN Group product certification.
Aboma Certification B.V.
Specialized in construction, metal, and transport sectors.
Sponsored listings
Frequently Asked Questions
EN 303-4:1999 is a standard published by the European Committee for Standardization (CEN). Its full title is "Heating boilers - Part 4: Heating boilers with forced draught burners - Special requirements for boilers with forced draught oil burners with outputs up to 70 kW and a maximum operating pressure of 3 bar - Terminology, special requirements, testing and marking". This standard covers: This standard is applicable to heating boilers with forced draught oil burners up to a nominal heat output of 70 kW. They are operated, either with negative pressure (natural draught boiler) or with positive pressure (pressurised boiler) in the combustion chamber, in accordance with the boiler manufacturer's instructions. This standard specifies the necessary terminology, the requirements on the materials and testing of them, and marking requirements for heating boilers.
This standard is applicable to heating boilers with forced draught oil burners up to a nominal heat output of 70 kW. They are operated, either with negative pressure (natural draught boiler) or with positive pressure (pressurised boiler) in the combustion chamber, in accordance with the boiler manufacturer's instructions. This standard specifies the necessary terminology, the requirements on the materials and testing of them, and marking requirements for heating boilers.
EN 303-4:1999 is classified under the following ICS (International Classification for Standards) categories: 01.040.91 - Construction materials and building (Vocabularies); 91.140.10 - Central heating systems. The ICS classification helps identify the subject area and facilitates finding related standards.
EN 303-4:1999 has the following relationships with other standards: It is inter standard links to ISO 7005-3:1988, ISO 185:1988, ISO 7-2:1982, ISO 228-2:1987, ISO 857:1990, ISO 2553:1992, ISO 228-1:1994, ISO 7005-1:1992, ISO 7005-2:1988, ISO 7-1:1994, EN IEC 60730-2-9:2026, EN IEC 60335-1:2023, EN 60529:1991, EN IEC 60730-2-9:2019, EN 14015:2004. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
EN 303-4:1999 is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.
Standards Content (Sample)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.R]QDþHYDQMHHeizkessel - Teil 4: Heizkessel mit Gebläsebrenner - Spezielle Anforderungen an Heizkessel mit Ölgebläsebrennern mit einer Leistung bis 70 kW und einem maximalen Betriebsdruck von 3 bar - Begriffe, besondere Anforderungen, Prüfung und KennzeichnungChaudieres de chauffage - Partie 4: Chaudieres avec bruleurs a air soufflé - Exigences spécifiques pour chaudieres avec bruleurs fioul a air soufflé avec une puissance utile jusqu'a 70 kW et une pression de service maximale de 3 bar - Terminologie, prescriptions spéciales, essais et marquageHeating boilers - Part 4: Heating boilers with forced draught burners - Special requirements for boilers with forced draught oil burners with outputs up to 70 kW and a maximum operating pressure of 3 bar - Terminology, special requirements, testing and marking91.140.10Sistemi centralnega ogreva
...