DIN EN 1717:2026-08

What is DIN EN 1717 about?

DIN EN 1717 specifies requirements for the protection of drinking water in drinking water installations. The standard describes how contamination caused by the backflow of non-potable water can be prevented and which backflow prevention devices should be used for this purpose. It applies to drinking water installations inside and outside buildings as well as to systems connected to the public drinking water supply network.

This makes DIN EN 1717 one of the most important standards for drinking water protection, drinking water hygiene, backflow prevention and the standards-compliant planning of drinking water installations.

What content does the standard cover?

The standard describes a risk-based procedure for selecting suitable protection devices and defines requirements for protecting drinking water against backsiphonage, backpressure and cross-connections. It also systematically classifies fluid categories, protective measures and protection fittings.

Topics covered at a glance:

• Protection of drinking water against backflow and contamination
• Risk assessment and fluid categories
• Selection and installation of protection devices
• Check valves, pipe interrupters and system separators
• Air gap and protection by atmospheric separation
• Requirements for drinking water installations and transfer points
• Practical examples of applications in buildings and technical systems

Why is the standard relevant in practice?

DIN EN 1717 supports planners, installation companies and operators in ensuring drinking water hygiene and standards-compliant backflow prevention in drinking water installations. It provides a uniform methodology for assessing contamination risks and selecting suitable system separators, pipe interrupters, check valves and other protection devices.

The standard is particularly relevant wherever drinking water may come into contact with other fluids, for example in heating systems, rainwater harvesting systems, dosing systems, commercial installations or industrial applications.

What changes have been made compared with the previous edition?

Compared with the previous European edition, the standard has been comprehensively revised. The most important changes include:

• Clarified and expanded scope
• Revision and updating of terms and definitions
• Complete revision of all figures
• Update of the protection matrix for protection devices and fluid categories
• Revision of the requirements for air gaps
• Completely revised annexes on protection devices and fluid categories
• Expanded application examples for selecting suitable protection devices
• Inclusion of a new annex with national A-deviations

The 2026 edition also includes the new informative Annex D “A-deviations”.

Target audience

DIN EN 1717 is aimed in particular at:

• Specialist planners for drinking water installations and building services engineering
• Engineers, experts and specialists in sanitary engineering
• Installers and plumbing, heating and air-conditioning companies
• Operators and persons responsible for drinking water systems
• Testing, hygiene and compliance officers in the field of drinking water

Conclusion

DIN EN 1717 is a key standard for the protection of drinking water installations, the prevention of backflow and backflow prevention in accordance with current European requirements. With its risk-based methodology, classification into fluid categories and detailed specifications for check valves, pipe interrupters and system separators, it provides an important basis for drinking water hygiene, system safety and the long-term protection of drinking water quality.

This document replaces DIN EN 1717:2026-02 .