EN 1856 Chimneys - Requirements for Metal Chimneys

The European standard “EN 1856 Chimneys - Requirements for metal chimneys” consists of the following sub-sections published under the same title:

• EN 1856-1 Part 1: System flue products standard describes the performance requirements for single and multi-walled system flue products with rigid metal linings, up to a nominal diameter of 1200 mm (including supports), used to carry combustion products from appliances to the outside atmosphere. This standard also includes requirements for marking, manufacturer's instructions, product information, and conformity assessment. Metal linings and metal connecting flue pipes, which are not covered here, are addressed in EN 1856-2 standard. This standard does not apply to structurally independent (free-standing or self-supporting) flues.

EN 1856-1 is a key European harmonized standard that defines performance requirements and test methods for metal system chimney products. It is part of a broader series of standards related to chimneys.

This standard has been widely adopted throughout the EU and is used as a reference in building regulations for the safe installation and performance of prefabricated metal chimney systems. This standard applies to single-wall and multi-wall system chimney products with rigid metal lining. These include:

• Chimney sections
• Fittings
• Ends
• supports

These components are designed to carry combustion products from heating devices (such as boilers, stoves, or fireplaces) to the outside atmosphere. They are available in nominal diameters up to 1.200 mm and include system flues (prefabricated, modular systems) rather than individual liners or pipes.

In contrast, these are structurally independent (freestanding or self-supporting) chimneys. Metal chimney liners and connecting chimney pipes are covered by the EN 1856-2 standard.

This standard also defines requirements for concentric flues used in room sealing applications, including air supply ducts (which may be metal or, in some revisions, certain plastics).

The EN 1856-1 standard sets comprehensive criteria to ensure safety, durability, and performance:

• Performance characteristics
• Thermal resistance
• Corrosion resistance
• mechanical strength
• Gas tightness
• Fire safety (including distance from flammable materials)
• Condensation resistance

This standard focuses primarily on stainless steel and other corrosion-resistant metals suitable for flue gases. It references test methods from relevant standards (e.g., EN 1859 standard test methods for metal flues). It includes corrosion testing, sampling procedures, and factory production control.

The EN 1856-1 standard plays a critical role in ensuring the following:

• Safe evacuation of flue gases
• Preventing carbon monoxide leaks
• Fire safety in buildings
• Compatibility with modern high-efficiency and condensing appliances.

This standard is generally used in conjunction with the following:

• EN 1443 (general chimney requirements)
• EN 1856-2 (metal linings and connecting pipes)
• EN 14989 series (room sealing applications)

Manufacturers must comply with this standard in order to obtain the CE mark for system flue products.

• EN 1856-2 Part 2: Metal flue linings and connecting flue pipes” standard describes the performance requirements for rigid or flexible metal flue linings, rigid metal connecting flue pipes and their fittings used to convey combustion products from appliances to the outside atmosphere (including supports). Vitreous enameled connecting flue pipes are also covered by this standard. Rigid flue linings can be used as flue linings for the renovation or adaptation of existing flues and as flue linings for custom-built flues.

The flexible metal chimney liners described in this standard are intended solely for the renovation or adaptation of existing chimneys. Flexible connecting chimney tubes and flexible products designed to be compressed or stretched along their length are outside the scope of this document. This standard also specifies marking, manufacturer's instructions, product information, and conformity assessment requirements. Single-wall and multi-wall system chimney products are covered by the EN 1856-1 standard.

The test methods defined in this standard are:

• Diameter measurement of flexible chimney liner.
• Gas tightness
• Tensile strength
• Crush resistance
• Flexibility test
• Torsional strength test
• Thermal performance test

The EN 1856-2 standard is a harmonized standard. It is part of a broader family of chimney standards and is widely used in the EU and associated countries.

This standard specifies the performance requirements and test methods for the following metal chimney components:

• Hard metal chimney liners
• Flexible metal chimney liners
• Rigid metal connecting flue pipes (including vitreous enamel versions)
• Their connecting parts and supports

These components are used to transport combustion products from heating devices (such as boilers, stoves, fireplaces) to the outside atmosphere.

Key exceptions include:

• Flexible chimney flues that can be compressed/stretched along their entire length.
• Single-walled and multi-walled chimney systems (these are covered by the EN 1856-1 standard)

This standard ensures that metal chimney liners and connecting pipes have the following characteristics:

• Safe
• Resistant
• Suitable for its intended use.
• Correctly classified in terms of performance.
• Supplied with clear labeling and installation instructions.

Products that meet this standard (including factory production control) can bear the CE mark.

The main applications include:

• Rigid metal chimney liners: Renovation/adaptation of existing brick chimneys, custom-made chimneys.
• Flexible metal chimney liners: Re-lining existing chimneys (especially those that are curved or damaged).
• Rigid metal connecting flue pipes: For connecting the appliance to the main flue (for internal, exposed use only).
• Enamel-coated connecting pipes: The same as above, but with a corrosion-resistant enamel coating.

The EN 1856-2 standard is mandatory for the placing on the market of metal chimney liners and connecting pipes in many European countries. Compliance ensures:

• Safety (prevention of carbon monoxide leaks and fire hazards)
• Durability in aggressive flue gas environments.
• Compatibility with modern high-efficiency condensing appliances.

The main differences between EN 1856-1 and EN 1856-2 standards are as follows:

• Main focus: EN 1856-1 standard complete chimney systems (sections, fittings, terminals, supports), EN 1856-2 standard metal chimney liners and connecting chimney pipes.
• Typical applications: EN 1856-1 standard for fully prefabricated chimney systems, EN 1856-2 standard for re-lining existing chimneys or connecting an appliance to the chimney.
• Rigid or flexible: EN 1856-1 standard for rigid system components, EN 1856-2 standard for rigid only (excluding flexible) components.
• Air supply ducts: EN 1856-1 standard is included for concentric systems, EN 1856-2 standard is for material-independent air ducts for room-insulated devices.

For many years, our organization, with its competent and experienced staff, has been understanding the needs of its clients, providing the advanced testing services they require, and assisting them in the establishment, implementation, and improvement of management systems. Within this framework, we also provide testing services in accordance with EN 1856 standards.