EN 125:2022+A1:2024

Flame supervision devices for gas burning appliances - Thermoelectric flame supervision devices

EN 13611:2019, Clause 1 applies with the following modification and addition:
Modification:
The 1st paragraph of EN 13611:2019, Clause 1 is replaced by:
This document specifies the safety, design, construction, and performance requirements and testing for
thermoelectric flame supervision devices, energized by a thermocouple intended for use with burners
and appliances burning one or more gaseous fuels, hereafter referred to as “controls”.
This document is applicable to controls with declared maximum inlet pressures up to and including
500 kPa and of nominal connection sizes up to and including DN 50.
Addition:
This document is not applicable to:
— the thermocouple;
— controls which use auxiliary energy (e.g. electrical energy supplied externally).
The 4th paragraph of EN 13611:2019, Clause 1 is removed.

Flammenüberwachungseinrichtungen für Gasgeräte - Thermo-elektrische Zündsicherungen

EN 13611:2019, Abschnitt 1, gilt mit folgender Änderung und Ergänzung:
Änderung:
Der erste Absatz von EN 13611:2019, Abschnitt 1, wird ersetzt durch:
Dieses Dokument legt die Sicherheits , Auslegungs , Konstruktions  und Leistungsanforderungen sowie die Prüfung von thermoelektrischen Zündsicherungen mit Thermoelement für Gasbrenner, Gasgeräte und ähnliche Anwendungen, nachstehend als „Regel- und Steuergeräte“ bezeichnet, fest.
Dieses Dokument gilt für Regel- und Steuergeräte mit einem angegebenen höchsten Eingangsdruck bis einschließlich 500 kPa und mit Anschlussnennweiten bis einschließlich DN 50.
Ergänzung:
Dieses Dokument gilt nicht für:
   das Thermoelement;
   Regel- und Steuergeräte mit Hilfsenergie (z. B. externe Stromversorgung).
Der vierte Absatz von EN 13611:2019, Abschnitt 1, entfällt.

Dispositifs de surveillance de flamme pour appareils à gaz - Dispositifs thermoélectriques de surveillance de flamme

Naprave za nadzor plamena pri plinskih aparatih - Termoelektrična varovala (vključno z dopolnilom A1)

Točka 1 standarda EN 13611:2019 se uporablja z naslednjo spremembo in dodatkom:
Sprememba:
Prvi odstavek točke 1 standarda EN 13611:2019 nadomešča naslednje besedilo:
Ta dokument določa zahteve za varnost, načrtovanje, izdelavo in delovanje ter preskušanje termoelektričnih varoval s termočlenom za uporabo z gorilniki in aparati, ki uporabljajo eno ali več plinastih goriv (v nadaljnjem besedilu »nadzorne naprave«).
Ta dokument se uporablja za nadzorne naprave z določenim največjim vstopnim tlakom do vključno 500 kPa in nazivno velikostjo priključkov do vključno DN 50.
Dodatek:
Ta dokument se ne uporablja za:
– termočlen;
– nadzorne naprave, ki uporabljajo pomožno energijo (npr. zunanja električna energija).
Četrti odstavek točke 1 standarda EN 13611:2019 je odstranjen.

General Information

• Status: Published
• Publication Date: 05-Nov-2024
• ICS: 27.060.20 - Gas fuel burners
• Technical Committee: CEN/TC 58 - Safety and control devices for burners and appliances burning gaseous or liquid fuels
• Drafting Committee: CEN/TC 58/WG 13 - Mechanics
• Current Stage: 6060 - Definitive text made available (DAV) - Publishing
• Start Date: 06-Nov-2024
• Completion Date: 06-Nov-2024
• Directive: 2016/426 - REGULATION (EU) 2016/426 OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL of 9 March 2016 on appliances burning gaseous fuels and repealing Directive 2009/142/EC
• Mandate: M/595 - [C(2023)4789] - Commission Implementing Decision of 20.7.2023 on a standardisation reques as regards gas appliances and fittings in support of Regulation (EU) 2016/426 of the European Parliament and of the Council
• Ref Project: SIST EN 125:2022+A1:2025 - Flame supervision devices for gas burning appliances - Thermoelectric flame supervision devices

Relations

• Merged From: EN 125:2022 - Flame supervision devices for gas burning appliances - Thermoelectric flame supervision devices
• Effective Date: 05-Oct-2024

Overview

EN 125:2022+A1:2024 is the CEN European standard for flame supervision devices for gas burning appliances, specifically covering thermoelectric flame supervision devices. Approved with Amendment 1 (July 2024), the standard defines design, construction, performance and safety requirements for thermoelectric controls used on gas burners and gas-fired appliances. It is intended for harmonisation across CEN member states and supports compliance with EU regulatory requirements.

Key topics and requirements

This standard addresses both mechanical and electrical/electronic aspects of flame supervision devices. Major technical topics include:

• Scope, terms and definitions specific to thermoelectric flame supervision devices.
• Classification: classes and groups of control, control functions, and types of DC‑supplied controls.
• Design and construction requirements for housings, materials, moving parts, seals, gas connections and mechanical integrity.
• Performance requirements covering leak‑tightness, torsion and bending, rated flow rate, durability and endurance.
• Electrical and EMC requirements for electronic parts and functional safety considerations.
• Protection against internal faults and methods to evaluate safety integrity (see SIL and PL).
• Testing methods: leak‑tightness (volumetric and pressure loss), operating torque/force tests, interlocks, sealing force and endurance tests.
• Annexes: normative and informative guidance, including calculation of pressure loss into leakage rate, electrical/electronic fault modes, materials for pressurized parts, reset functions, SIL and PL determination, and environmental aspects.
• Marking, instructions and warning notices required for conformity and safe use.

Keywords: EN 125:2022+A1:2024, flame supervision devices, thermoelectric, gas burning appliances, leak‑tightness, SIL, PL, EMC.

Applications and who uses it

EN 125:2022+A1:2024 is used by:

• Manufacturers of thermoelectric flame supervision devices and gas appliance controls to design and certify products.
• Appliance OEMs integrating flame controls into boilers, gas burners, heaters, cookers and industrial combustion systems.
• Testing laboratories and certification bodies performing performance, leak and EMC tests, and assessing conformity with EU Directives.
• Safety and design engineers specifying controls to achieve required Safety Integrity Levels (SIL) or Performance Levels (PL).
• Regulators and compliance teams using Annex ZA to relate the standard to EU Regulation 2016/426 on gas appliances.

Related standards

• EN 125 references and aligns with other CEN standards and EU requirements for burners and pressure accessories; see Annex ZA for the relationship with Regulation (EU) 2016/426.
• Relevant for standards on EMC, pressure equipment, and general burner safety standards.

For manufacturers and safety engineers, EN 125:2022+A1:2024 is essential reading when designing, testing or certifying thermoelectric flame supervision devices for gas burning appliances.

Standards Content (Sample)

SLOVENSKI STANDARD
01-marec-2025
Nadomešča:
SIST EN 125:2022
Naprave za nadzor plamena pri plinskih aparatih - Termoelektrična varovala
(vključno z dopolnilom A1)
Flame supervision devices for gas burning appliances - Thermoelectric flame supervision
devices
Flammenüberwachungseinrichtungen für Gasgeräte - Thermo-elektrische
Zündsicherungen
Dispositifs de surveillance de flamme pour appareils à gaz - Dispositifs
thermoélectriques de surveillance de flamme
Ta slovenski standard je istoveten z: EN 125:2022+A1:2024
ICS:
27.060.20 Plinski gorilniki Gas fuel burners
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 125:2022+A1
EUROPEAN STANDARD
NORME EUROPÉENNE
November 2024
EUROPÄISCHE NORM
ICS 27.060.20
English Version
Flame supervision devices for gas burning appliances -
Thermoelectric flame supervision devices
Dispositifs de surveillance de flamme pour appareils à Flammenüberwachungseinrichtungen für Gasgeräte -
gaz - Dispositifs thermoélectriques de surveillance de Thermo-elektrische Zündsicherungen
flamme
This European Standard was approved by CEN on 8 August 2022 and includes Amendment 1 approved by CEN on 3 July 2024.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2024 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 125:2022+A1:2024 E
worldwide for CEN national Members.

Contents Page
European foreword . 5
Introduction . 6
1 Scope . 8
2 Normative references . 8
3 Terms and definitions . 8
4 Classification . 9
4.1 Classes of control . 9
4.2 Groups of control . 9
4.3 Classes of control functions . 9
4.4 Types of DC supplied controls . 9
5 Test conditions and uncertainty of measurements . 9
6 Design and construction . 10
6.1 General . 10
6.2 Mechanical parts of the control . 10
6.2.1 Appearance . 10
6.2.2 Holes . 10
6.2.3 Breather holes . 10
6.2.4 Screwed fastenings . 10
6.2.5 Jointing . 10
6.2.6 Moving parts . 10
6.2.7 Sealing caps . 10
6.2.8 Dismantling and reassembly . 10
6.2.9 Auxiliary canals and orifices . 10
6.2.10 Presetting device . 10
6.3 Materials . 10
6.3.1 General material requirements . 10
6.3.2 Housing . 11
6.3.3 Zinc alloys . 11
6.3.4 Springs . 11
6.3.5 Resistance to corrosion and surface protection . 11
6.3.6 Impregnation . 11
6.3.7 Seals for glands for moving parts . 11
6.4 Gas connections . 11
6.4.1 Making connections. 11
6.4.2 Connection sizes . 11
6.4.3 Threads . 11
6.4.4 Union joints . 11
6.4.5 Flanges . 11
6.4.6 Compression fittings . 11
6.4.7 Nipples for pressure test . 11
6.4.8 Strainers . 11
6.5 Electronic parts of the control . 11
6.6 Protection against internal faults for the purpose of functional safety . 12
7 Performance . 12
7.1 General . 12
7.2 Leak-tightness . 12
7.2.1 Requirements . 12
7.2.2 Test . 13
7.3 Torsion and bending . 13
7.4 Rated flow rate . 13
7.4.1 Requirement . 13
7.4.2 Test . 14
7.4.3 Conversion of air flow rate . 14
7.5 Durability. 14
7.6 Performance tests for electronic controls . 14
7.7 Long-term performance for electronic controls . 14
7.8 Data exchange . 14
7.101 Operating torque and force . 14
7.101.1 Requirement . 14
7.101.2 Test for operating torque and force . 15
7.102 Interlocks . 15
7.102.1 Requirement . 15
7.102.2 Test for interlocks . 15
7.103 Closing current . 15
7.103.1 Requirement . 15
7.103.2 Test for closing current . 15
7.104 Sealing force . 16
7.104.1 Requirement . 16
7.104.2 Test for sealing force . 16
7.105 Endurance . 17
7.105.1 Requirement . 17
7.105.2 Endurance test . 17
8 EMC/Electrical requirements . 18
9 Electromagnetic compatibility (EMC) . 18
10 Marking, instructions . 18
10.1 Marking . 18
10.2 Instructions . 18
10.3 Warning notice . 19
Annex A (informative) Abbreviations and Symbols . 20
Annex B (informative) Leak-tightness test for gas controls − volumetric method . 21
Annex C (informative) Leak-tightness test − pressure loss method . 22
Annex D (normative) Calculation of pressure loss into leakage rate . 23
Annex E (normative) Electrical/electronic component fault modes . 24
Annex F (normative) Additional requirements for safety accessories and pressure
accessories as defined in EU Directive 2014/68/EU. 25
Annex G (normative) Materials for pressurized parts . 26
Annex H (normative) Additional materials for pressurized parts . 27
Annex I (normative) Requirements for controls used in DC supplied burners and burning
gaseous or liquid fuels appliances . 28
Annex J (normative) Method for the determination of the Safety Integrity Level (SIL) . 29
Annex K (normative) Method for the determination of a Performance Level (PL) . 30
Annex L (informative) Relationship between Safety Integrity Level (SIL) and
Performance Level (PL) . 31
Annex M (normative) Reset functions . 32
Annex N (informative) Guidance document on Environmental Aspects . 33
Annex O (normative) Seals of elastomers, cork and synthetic fibre mixtures . 34
Annex AA (informative) Types of flame supervision devices. 35
Annex ZA (informative) Relationship between this European Standard and the Essential
Requirements of Regulation (EU) 2016/426 aimed to be covered . 37
Bibliography . 40

European foreword
This document (EN 125:2022+A1:2024) has been prepared by Technical Committee CEN/TC 58 “Safety
and control devices for burners and appliances burning gaseous or liquid fuels”, the secretariat of which
is held by BSI.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by May 2025, and conflicting national standards shall be
withdrawn at the latest by November 2027.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document includes Amendment 1 approved by CEN on 3 July 2024.
The start and finish of text introduced or altered by amendment is indicated in the text by tags !".
This document supersedes !EN 125:2022.
This document differs from EN 125:2022 as follows:
a) Annex ZA has been brought in line with Mandate M/595 and the normative references are updated."
!Deleted text"
This document has been prepared under a Standardization Request given to CEN by the European
Commission and the European Free Trade Association, and supports essential requirements of
EU Directive(s) / Regulation(s).
For relationship with EU Directive(s) / Regulation(s), see informative Annex ZA, which is an integral part
of this document.
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia,
Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland,
Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of North
Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the United
Kingdom.
Introduction
This document is intended to be used in conjunction with EN 13611:2019.
EN 13611:2019 recognizes the safety level specified by CEN/TC 58 and is regarded as a horizontal
standard dealing with the safety, construction, performance and testing of controls for burners and
appliances burning gaseous and/or liquid fuels.
The general requirements for controls are given in EN 13611:2019, and methods for classification and
assessment for new controls and control functions are given in EN 14459:2021 (see Figure 1).
EN 126:2012 (see Figure 1) specifies multifunctional controls combining two or more controls and
Application Control Functions, one of which is a mechanical control function. The requirements for
controls and Application Control Functions are given in the specific control standard (see Figure 1,
control functions).
Figure 1 — Interrelation of control standards
EN 13611:2019 should be used in conjunction with the specific standard for a specific type of control (e.g.
!EN 88-1:2022+A1:2023", !EN 88-2:2022+A1:2024", !EN 88-3:2022+A1:2024",
!EN 125:2022+A1:2024", EN 126:2012, EN 161:2022, !EN 257:2022+A1:2023", EN 298:2022,
!EN 1106:2022+A1:2023", EN 1643:2022, !EN 1854:2022+A1:2023", EN 12067-2:2022,
!EN 16304:2022+A1:2024", EN 16340:2014, EN 16678:2022 and
!EN 16898:2022+A1:2023"), or for controls for specific applications.
EN 13611:2019 can also be applied, so far as reasonable, to controls not mentioned in a specific standard
and to controls designed on new principles, in which case additional requirements can be necessary.
EN 14459:2021 provides methods for classification and assessment of new control principles.
Primarily in industrial applications it is common practice to rate the safety of a plant based on values
describing the likelihood of a dangerous failure. These values are being used to determine Safety Integrity
Levels or Performance Levels when the system is being assessed in its entirety.
CEN/TC 58 standards for safety relevant controls do go beyond this approach, because for a certain life
time for which the product is specified, designed and tested a dangerous failure is not allowed at all.
Failure modes are described and assessed in greater detail.
Measures to prevent from dangerous situations are defined. Field experience over many decades is
reflected in the CEN/TC 58 standards. Requirements of EN 13611:2019 can be considered as proven in
practice.
This document refers to clauses of EN 13611:2019 or adapts clauses by stating “with the following
modification”, “with the following addition”, “is replaced by the following” or “is not applicable” in the
corresponding clause.
This document adds clauses or subclauses to the structure of EN 13611:2019 which are particular to this
document. Subclauses which are additional to those in EN 13611:2019 are numbered starting from 101.
Additional Annexes are designed as Annex AA, BB, CC, etc. It should be noted that these clauses,
subclauses and Annexes are not indicated as an addition.
1 Scope
EN 13611:2019, Clause 1 applies with the following modification and addition:
Modification:
st
The 1 paragraph of EN 13611:2019, Clause 1 is replaced by:
This document specifies the safety, design, construction, and performance requirements and testing for
thermoelectric flame supervision devices, energized by a thermocouple intended for use with burners
and appliances burning one or more gaseous fuels, hereafter referred to as “controls”.
This document is applicable to controls with declared maximum inlet pressures up to and including
500 kPa and of nominal connection sizes up to and including DN 50.
Addition:
This document is not applicable to:
— the thermocouple;
— controls which use auxiliary energy (e.g. electrical energy supplied externally).
th
The 4 paragraph of EN 13611:2019, Clause 1 is removed.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
!EN 13611:2019", Safety and control devices for burners and appliances burning gaseous and/or
liquid fuels — General requirements
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 13611:2019 and the following
apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:

— ISO Online browsing platform: available at https://www.iso.org/obp
— IEC Electropedia: available at https://www.electropedia.org/
3.101
thermocouple
thermoelectric flame sensing element that responds to the temperature of the supervised flame, and in
which the flame effect produces an electromotive force (e.m.f.)
3.102
thermoelectric flame supervision device
control which, in response to the e.m.f. produced by the thermocouple, maintains the gas way to the main
burner or the main burner and the pilot burner open and which shuts off the gas way to the main burner
at least, after extinction of the supervised flame
Note 1 to entry: For further reference, see Figure AA.1 and Figure AA.2.
3.103
ignition interlock
part which prevents the igniter from operating as long as the main gas way is open
3.104
re-start interlock
mechanism which prevents the re-opening of the gas way to the main burner or to the main burner and
the pilot burner until the armature plate has separated from the magnetic element
Note 1 to entry: For further information, see Figure AA.1 and Figure AA.2.
3.105
sealing force
force acting on the closure member when the closure member is in the closed position, independent of
any force provided by fuel gas pressure
3.106
closed position
position of the closure member(s) in the absence of the thermoelectric energy
4 Classification
4.1 Classes of control
EN 13611:2019, 4.1 is replaced by the following:
Controls shall be classified A, B or C according to the number of operations as tested in 7.105.2.2.
4.2 Groups of control
Shall be according to EN 13611:2019, 4.2.
4.3 Classes of control functions
EN 13611:2019, 4.3 is not applicable.
4.4 Types of DC supplied controls
EN 13611:2019, 4.4 is not applicable.
5 Test conditions and uncertainty of measurements
Shall be according to EN 13611:2019, Clause 5.
EN 125:2022+
...