prEN IEC 60335-2-73:2026
(Main)Household and similar electrical appliances - Safety - Part 2-73: Particular requirements for fixed immersion heaters
- Abstract
This European standard deals with the safety of electric thermal-storage room heaters intended to heat the room in which they are located, their rated voltage being not more than 250 V for single phase and 480 V for other appliances.
- Status
- Not Published
- Publication Date
- 23-Feb-2027
- Technical Committee
- CLC/TC 61 - Safety of household and similar electrical appliances
- Drafting Committee
- CLC/TC 61 - Safety of household and similar electrical appliances
- Current Stage
- 4020 - Enquiry circulated - Enquiry
- Start Date
- 14-Aug-2026
- Due Date
- 19-Aug-2025
- Completion Date
- 14-Aug-2026
prEN IEC 60335-2-73:2026 is a CENELEC draft European standard for the safety of fixed immersion heaters. It gives particular requirements for household and similar electric immersion heaters used to heat water in a tank open to the atmosphere, and it is written for manufacturers, installers, test laboratories, and certification or quality teams.
What does prEN IEC 60335-2-73:2026 specify?
prEN IEC 60335-2-73:2026 specifies safety requirements for fixed electric immersion heaters for household and similar use. It covers heaters installed in a water tank open to the atmosphere, used to heat water below boiling, including direct current (DC) supplied appliances and units intended as an alternative heating source in central heating boilers.
The scope includes appliances used by the public in places such as shops, light industry, and farms when they can present a danger to non-specialist users. It excludes industrial-only appliances, special-atmosphere locations, and several other heater types covered by other parts of the IEC 60335 series.
The document follows the IEC Part 2 format. It replaces or modifies selected clauses of IEC 60335-1, keeps the Part 1 structure from Clause 1 through Clause 32, and uses added material identified with 101 numbering. The annexes of Part 1 apply, and the bibliography points to related standards used alongside this one.
What are the key requirements of prEN IEC 60335-2-73:2026?
prEN IEC 60335-2-73:2026 works as a Part 2 standard, so it supplements and modifies IEC 60335-1 rather than standing alone. In practice, users need to read the general appliance safety rules in Part 1 first, then apply the extra fixed-immersion-heater requirements here.
Classification, marking, and instructions
Clause 6 requires immersion heaters to be class I, class II, or class III. Clause 7 requires marking for multiple-supply appliances and a warning with the substance of "Do not cover". The installation instructions must tell the installer the tank type and dimensions, the heater position in the tank, and the need to check for water before first switch-on.
Test conditions and normal operation
Clause 3 modifies "normal operation" to mean operation after installation in the smallest specified tank, thermally insulated and filled with water. This matters because the safety tests are based on the smallest intended installation, not a generic laboratory setup.
Heating and temperature-rise control
Clause 11 adds a method for measuring temperatures on external accessible surfaces using the probe in Figure 101, and Table 101 sets the allowable temperature rises for specified surfaces. The test runs to steady conditions, but it can stop after 24 h if a thermal control has operated. For users, this means surface heating and user-contact risk are checked under realistic operating conditions.
Abnormal operation
Clause 19 tests the appliance with the tank empty and with relevant thermal controls short-circuited, then with water above the heating element. The standard also limits the water temperature for this abnormal-operation check. In practice, designers need a heater that remains safe if the tank is empty or if control components fail.
Construction and protection measures
Clause 22 requires a seal or other means to prevent leakage after installation, and it limits rotation of the supply-terminal compartment. Clause 24 requires thermal cut-outs used for Clause 19 compliance to be non-self-resetting and independent of the thermostat. Clause 27 adds earthing requirements for metal parts of class I immersion heaters that are in contact with water.
What terms does prEN IEC 60335-2-73:2026 define?
- Normal operation - operation after installation in the smallest specified tank, with the tank insulated and filled with water.
- Class I - an appliance type that relies on protective earthing; in this standard, metal parts in contact with water are permanently connected to the earthing terminal.
- Class II - an appliance type intended to rely on double or reinforced insulation rather than protective earthing.
- Class III - an appliance type supplied from safety extra-low voltage.
- Thermal control - a control that may operate during the heating test and can trigger the 24 h limit in Clause 11.
- Thermal cut-out - a safety device used for abnormal-operation protection; here it must not be self-resetting.
- Direct current (DC) - a supply form explicitly included in the scope.
Who uses prEN IEC 60335-2-73:2026?
Manufacturers of fixed immersion heaters use it for design, marking, instruction manuals, and safety testing. Test laboratories and certification bodies use it for heating, abnormal-operation, leakage, and construction checks. Installers and system designers use it to match the heater to the tank type, mounting position, earthing, and water-level conditions. Buyers, quality managers, and compliance teams use it to confirm that a product is meant for open-tank water heating rather than another water-heater category.
What changed in prEN IEC 60335-2-73:2026 from the previous edition?
prEN IEC 60335-2-73:2026 is based on IEC 60335-2-73:2024 and supersedes EN 60335-2-73:2003, its Amendment 1:2006, Amendment 2:2009, and related corrigenda.
The main technical changes stated in the document are:
- alignment with IEC 60335-1:2020
- some notes converted into normative text, including in Clause 1 and 19.2
- addition of external accessible surface temperatures in Clause 11
Which standards are used with prEN IEC 60335-2-73:2026?
prEN IEC 60335-2-73:2026 is intended to be used with IEC 60335-1, the general household-appliance safety standard, and with the companion amendment prAA:2026. IEC 60584-1 is cited for thermocouple specifications used with the surface-temperature probe in Figure 101.
The bibliography also names related IEC and ISO documents that help place this part in context:
- IEC 60335-2-15 - heating liquids
- IEC 60335-2-21 - storage water heaters
- IEC 60335-2-35 - instantaneous water heaters
- IEC 60335-2-55 - aquarium and garden pond appliances
- IEC 60335-2-74 - portable immersion heaters
- ISO 13732-1 - assessment of human response to hot surfaces
What does the prEN IEC 60335-2-73:2026 document contain?
The document contains the full Part 2 structure from scope through safety-related clauses, plus the Part 1 references it modifies. It includes a specific temperature-rise measurement method in Clause 11, a probe design in Figure 101, and a temperature-rise table for accessible surfaces in Table 101. It also sets out abnormal-operation tests, construction checks for sealing and terminal-compartment rotation, and earthing requirements for class I water-contacting metal parts.
Relations
- Effective Date
- 10-Sep-2024
- Effective Date
- 30-Jul-2024
- Effective Date
- 30-Jul-2024
- Effective Date
- 30-Jul-2024
- Effective Date
- 30-Jul-2024
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Frequently Asked Questions
prEN IEC 60335-2-73:2026 is a draft published by CLC. Its full title is "Household and similar electrical appliances - Safety - Part 2-73: Particular requirements for fixed immersion heaters". This standard covers: This European standard deals with the safety of electric thermal-storage room heaters intended to heat the room in which they are located, their rated voltage being not more than 250 V for single phase and 480 V for other appliances.
This European standard deals with the safety of electric thermal-storage room heaters intended to heat the room in which they are located, their rated voltage being not more than 250 V for single phase and 480 V for other appliances.
prEN IEC 60335-2-73:2026 is classified under the following ICS (International Classification for Standards) categories: 91.140.65 - Water heating equipment. The ICS classification helps identify the subject area and facilitates finding related standards.
prEN IEC 60335-2-73:2026 has the following relationships with other standards: It is inter standard links to prEN IEC 60335-2-73:2026/prAA:2026, EN 60335-2-73:2003/A1:2006, EN 60335-2-73:2003/A11:2021, EN 60335-2-73:2003/A2:2009, EN 60335-2-73:2003. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
prEN IEC 60335-2-73:2026 is associated with the following European legislation: EU Directives/Regulations: 2014/35/EU, 2014/53/EU, 2014/55/EU; Standardization Mandates: M/511, M/536, M/585. When a standard is cited in the Official Journal of the European Union, products manufactured in conformity with it benefit from a presumption of conformity with the essential requirements of the corresponding EU directive or regulation.
prEN IEC 60335-2-73:2026 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)
SLOVENSKI STANDARD
01-oktober-2026
Gospodinjski in podobni električni aparati - Varnost - 2-73. del: Posebne zahteve
za pritrjene potopne grelnike
Household and similar electrical appliances - Safety - Part 2-73: Particular requirements
for fixed immersion heaters
Sicherheit elektrischer Geräte für den Hausgebrauch und ähnliche Zwecke - Teil 2-73:
Besondere Anforderungen für ortsfeste Heizeinsätze
Appareils électrodomestiques et analogues - Sécurité - Partie 2-73: Règles particulières
pour les thermoplongeurs installés à poste fixe
Ta slovenski standard je istoveten z: prEN IEC 60335-2-73:2026
ICS:
13.120 Varnost na domu Domestic safety
91.140.65 Oprema za ogrevanje vode Water heating equipment
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EUROPEAN STANDARD DRAFT
prEN IEC 60335-2-73
NORME EUROPÉENNE
EUROPÄISCHE NORM
August 2026
ICS 91.140.65 Will supersede EN 60335-2-73:2003; EN 60335-2-
73:2003/A1:2006; EN 60335-2-73:2003/A2:2009; EN
60335-2-73:2003/A11:2021
English Version
Household and similar electrical appliances - Safety - Part 2-73:
Particular requirements for fixed immersion heaters
(IEC 60335-2-73:2024)
Appareils électrodomestiques et analogues - Sécurité - Sicherheit elektrischer Geräte für den Hausgebrauch und
Partie 2-73: Règles particulières pour les thermoplongeurs ähnliche Zwecke - Teil 2-73: Besondere Anforderungen für
installés à poste fixe ortsfeste Heizeinsätze
(IEC 60335-2-73:2024) (IEC 60335-2-73:2024)
This draft European Standard is submitted to CENELEC members for enquiry.
Deadline for CENELEC: 2026-11-06.
The text of this draft consists of the text of IEC 60335-2-73:2024.
If this draft becomes a European Standard, CENELEC 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.
This draft European Standard was established by CENELEC in three official versions (English, French, German).
A version in any other language made by translation under the responsibility of a CENELEC member into its own language and notified to
the CEN-CENELEC Management Centre has the same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the
Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Türkiye and the United Kingdom.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are aware and to
provide supporting documentation.
Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without notice and
shall not be referred to as a European Standard.
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2026 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Project: 80416 Ref. No. prEN IEC 60335-2-73:2026 E
European foreword
This document (prEN IEC 60335-2-73:2026) consists of the text of document IEC 60335-2-73:2024,
prepared by IEC/TC 61 "Safety of household and similar electrical appliances".
This document is currently submitted to the Enquiry.
The following dates are proposed:
• latest date by which the existence of this document (doa) dav + 6 months
has to be announced at national level
• latest date by which this document has to be (dop) dav + 12 months
implemented at national level by publication of an
identical national standard or by endorsement
• latest date by which the national standards (dow) dav + 36 months
conflicting with this document have to be withdrawn (to be confirmed or
modified when voting)
This document will supersede EN 60335-2-73:2003 and all of its amendments and corrigenda (if any).
This document is read in conjunction with prEN IEC 60335-2-73:2026/prAA:2026.
IEC 60335-2-73 ®
Edition 3.0 2024-03
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Household and similar electrical appliances – Safety –
Part 2-73: Particular requirements for fixed immersion heaters
Appareils électrodomestiques et analogues – Sécurité –
Partie 2-73: Règles particulières pour les thermoplongeurs installés à poste fixe
IEC 60335-2-73:2024-03(en-fr)
IEC 60335-2-73 ®
Edition 3.0 2024-03
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Household and similar electrical appliances – Safety –
Part 2-73: Particular requirements for fixed immersion heaters
Appareils électrodomestiques et analogues – Sécurité –
Partie 2-73: Règles particulières pour les thermoplongeurs installés à poste fixe
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 91.140.65 ISBN 978-2-8322-8459-9
– 2 – IEC 60335-2-73:2024 © IEC 2024
CONTENTS
FOREWORD . 3
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 8
3 Terms and definitions . 8
4 General requirement . 8
5 General conditions for the tests . 8
6 Classification . 8
7 Marking and instructions . 9
8 Protection against access to live parts . 9
9 Starting of motor-operated appliances . 9
10 Power input and current . 9
11 Heating . 9
12 Charging of metal-ion batteries . 10
13 Leakage current and electric strength at operating temperature . 10
14 Transient overvoltages . 10
15 Moisture resistance . 10
16 Leakage current and electric strength . 11
17 Overload protection of transformers and associated circuits . 11
18 Endurance . 11
19 Abnormal operation . 11
20 Stability and mechanical hazards . 11
21 Mechanical strength . 11
22 Construction . 11
23 Internal wiring . 12
24 Components . 12
25 Supply connection and external flexible cords . 12
26 Terminals for external conductors . 12
27 Provision for earthing . 12
28 Screws and connections . 12
29 Clearances, creepage distances and solid insulation . 12
30 Resistance to heat and fire . 12
31 Resistance to rusting . 13
32 Radiation, toxicity and similar hazards . 13
Annexes . 14
Bibliography . 15
Figure 101 – Probe for measuring surface temperatures . 13
Table 101 – Maximum temperature rises for specified external accessible surfaces
under normal operating conditions . 10
IEC 60335-2-73:2024 © IEC 2024 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
HOUSEHOLD AND SIMILAR ELECTRICAL APPLIANCES –
SAFETY –
Part 2-73: Particular requirements for fixed immersion heaters
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
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9) IEC draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). IEC takes no position concerning the evidence, validity or applicability of any claimed patent rights in
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shall not be held responsible for identifying any or all such patent rights.
IEC 60335-2-73 has been prepared by IEC technical committee 61: Safety of household and
similar electrical appliances. It is an International Standard.
This third edition cancels and replaces the second edition published in 2002, Amendment 1:
2006 and Amendment 2: 2009. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) the text has been aligned with IEC 60335-1:2020;
b) some notes have been converted to normative text (Clause 1, 19.2);
c) addition of external accessible surface temperatures (Clause 11).
– 4 – IEC 60335-2-73:2024 © IEC 2024
The text of this International Standard is based on the following documents:
Draft Report on voting
61/6954/CDV 61/7055A/RVC
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/publications.
A list of all parts of the IEC 60335 series, under the general title: Household and similar
electrical appliances – Safety, can be found on the IEC website.
This part 2 is to be used in conjunction with the latest edition of IEC 60335-1 and its
amendments unless that edition precludes it; in that case, the latest edition that does not
preclude it is used. It was established on the basis of the sixth edition (2020) of that standard.
NOTE 1 When "Part 1" is mentioned in this standard, it refers to IEC 60335-1.
This part 2 supplements or modifies the corresponding clauses in IEC 60335-1, so as to convert
that publication into the IEC standard: Particular requirements for fixed immersion heaters.
When a particular subclause of Part 1 is not mentioned in this part 2, that subclause applies as
far as is reasonable. When this standard s
...