EN IEC 60335-2-66:2026
(Main)Household and similar electrical appliances - Safety - Part 2-66: Particular requirements for water-bed heaters
- Abstract
This European Standard deals with the safety of electric water-bed heaters and their associated control units, for household and similar purposes, their rated voltage being not more than 250 V, including direct current (DC) supplied appliances.
- Status
- Published
- Publication Date
- 13-Aug-2026
- 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
- 6060 - Document made available - Publishing
- Start Date
- 14-Aug-2026
- Due Date
- 04-Nov-2027
- Completion Date
- 14-Aug-2026
EN IEC 60335-2-66:2026 is the CENELEC European Standard for the safety of electric water-bed heaters and their associated control units used for household and similar purposes. It applies to appliances with rated voltage up to 250 V, including direct current (DC) supplied appliances, and is written for manufacturers, test laboratories, compliance teams and buyers who need to judge whether a water-bed heater is designed and tested for safe use.
What does EN IEC 60335-2-66:2026 specify?
EN IEC 60335-2-66:2026 specifies particular safety requirements for electric water-bed heaters and their associated control units. It focuses on hazards that matter in practice for products placed under a water mattress: electric shock, overheating, abnormal operation, mechanical loading, moisture, and installation-related risks.
The scope includes appliances for household and similar purposes, and it also covers products used in places such as hotels when they can present a risk to the public. It excludes appliances for medical purposes and appliances intended for immersion in water during use.
EN IEC 60335-2-66:2026 is structured as a Part 2 standard. It supplements and modifies the general safety requirements of Part 1, then adds water-bed-heater-specific requirements in Clauses 1 to 32. The annexes of Part 1 apply.
What are the key requirements of EN IEC 60335-2-66:2026?
EN IEC 60335-2-66:2026 sets out how the heater is to be installed, tested, marked and constructed so that it remains safe under normal use and expected faults. The most important points are below.
Use conditions and test setup
- Clause 5.10 defines a specific normal-use test arrangement with a wooden base, an open-cell polyether layer, a water mattress and the heater installed as it would be in service. This matters because the safety tests are based on realistic support and loading conditions, not a generic bench setup.
- Clause 5.3 links the mechanical test of 21.101 to the heating test sequence. That tells laboratories when to apply the stress test so the results reflect the heater’s actual operating condition.
Classification, ingress protection and electrical safety
- Clause 6.1 limits class III appliances to 24 V. In practice, this keeps extra-low-voltage products within a defined safety boundary.
- Clause 6.2 requires parts intended to be placed under the water mattress, other than class III parts, to be at least IPX7. That is important because the heater and its related parts are used close to water and must resist immersion-type exposure.
- Clause 13.2 sets different leakage-current limits for class II appliances with a metal screen connected to live parts, depending on the selector-switch position. For designers and testers, the switch setting must be considered when checking leakage performance.
Marking, instructions and installation information
- Clause 7.1 requires warnings and use information on the appliance, including careful installation under the mattress, a flat and continuous support, correct central positioning, and use only for heating water-beds. This helps prevent the common installation mistakes that can create overheating or physical damage.
- Clause 7.12 requires instructions to identify the correct detachable control unit, state that the appliance is not intended for hospitals, and warn against inserting sharp objects or allowing bedding to contact the heater.
- Clause 7.12.1 adds installation instructions for the positioning of the heater and any temperature-sensing element, the minimum mattress dimensions, the minimum water depth, and any extra support material needed on a soft support.
- Clause 7.101 requires detachable control units to be marked with their rated voltage or range, supply nature, manufacturer identification, model or type reference, and the heater identification.
Heating, abnormal operation and mechanical strength
- Clause 11 sets the temperature-rise method and uses fine-wire thermocouples with metal plates for measuring surface temperatures. Clause 11.8 limits the heater surface temperature rise, with a higher limit only under folded material, and Clause 11.101 adds a heat-stroke check based on the mattress surface temperature. This is the core comfort-and-safety control for a product that is meant to stay under a person’s sleeping surface.
- Clause 19 checks abnormal operation with the mattress empty or without folded material, and with the heater positioned so it projects beyond the mattress envelope in one test. These tests look for runaway heating and fire or burn risk when the appliance is misused or misinstalled.
- Clause 21.101 subjects appliances with a flexible support to repeated loading using the wood block shown in Figure 101. This reflects the physical stress the heater and mattress see in everyday use.
Construction, wiring and component rules
- Clause 22.101 requires class II appliances with a metal screen connected to live parts, and without a polarized plug, to include a means of showing that the plug has been inserted so leakage current is minimized. Clause 22.102 requires supplementary insulation for class I appliances with an earthed metal screen.
- Clause 23.5 prohibits natural rubber as insulation for internal wiring. Clause 24.101 requires thermal cut-outs not to be self-resetting, which matters because a safety device must stay open after a fault until deliberately reset.
- Clause 25 allows Type Z attachment and sets cord tests in Table 12. Clause 25.23 also requires the insulation of interconnection cords to be at least equivalent to ordinary PVC sheathed flexible cord.
- Clause 29.3 requires multilayer insulation to remain inaccessible after installation, and Clause 30.1 excludes the heater enclosure from the heat-and-fire test in that clause.
What terms does EN IEC 60335-2-66:2026 define?
EN IEC 60335-2-66:2026 defines the terms used to apply the safety requirements consistently.
- Water-bed heater - an appliance with a heating element in an enclosure intended for use under a water mattress.
- Detachable control unit - a separate control unit that is identified for use with the heater and has to be marked accordingly.
- Class III appliance - a low-voltage appliance, and in this standard its rated voltage must not exceed 24 V.
- Class II appliance - an appliance with the insulation arrangements used in this standard for higher protection against electric shock, including special rules when a metal screen is fitted.
- IPX7 - the ingress-protection level required for parts placed under the water mattress when they are not class III parts.
- Part 1 - IEC 60335-1, the general safety standard that this Part 2 modifies for water-bed heaters.
- DC - direct current, which is explicitly included in the scope.
Who uses EN IEC 60335-2-66:2026?
EN IEC 60335-2-66:2026 is used by manufacturers of water-bed heaters and their control units, because it tells them what the product must withstand and what it must be marked with. Design engineers use it to define temperature control, wiring, insulation, enclosure and cord details.
Testing and certification laboratories use it to run the heating, leakage, abnormal-operation and mechanical-load tests. Quality managers and compliance teams use it to verify instructions, labels, component choices and construction details before release.
It is also relevant to buyers and procurement staff who specify heaters for household, hotel or other similar use, because it defines the safety basis for the product category. National committees and conformity assessment bodies use it as the European adoption of the IEC text.
What changed in EN IEC 60335-2-66:2026 from the previous edition?
EN IEC 60335-2-66:2026 supersedes EN 60335-2-66:2003 and its amendments and corrigenda. The IEC text states that this third edition cancels and replaces the second edition published in 2002, Amendment 1:2008 and Amendment 2:2011.
The main technical changes listed are:
- alignment with IEC 60335-1:2020;
- conversion of some notes to normative text in Clause 1, 19.4 and 22.101;
- clarification of requirements for remote operation in 22.40, 22.49 and 22.51.
Which standards are used with EN IEC 60335-2-66:2026?
EN IEC 60335-2-66:2026 is used with IEC 60335-1, the general safety standard for household and similar electrical appliances. The Part 2 text is built on the latest edition of Part 1 and modifies it where needed for water-bed heaters.
ISO 2439 contributes the hardness test method for the open-cell polyether used in the normal-operation test setup. That matters because the support material has to be prepared consistently in testing.
The document also points to the IEC 60601 series as the medical-equipment series excluded from scope, and the bibliography adds IEC 60601 (all parts). The introduction also mentions IEC 60364 as the wiring-rules basis the standard tries to align with where possible. EN IEC 60335-2-66:2026/A11:2026 is identified in the European foreword as the text to be read with this document.
What does the EN IEC 60335-2-66:2026 document contain?
EN IEC 60335-2-66:2026 contains detailed test methods for normal operation, heating, abnormal operation, mechanical stress and cord retention. It also contains specific installation conditions for the mattress, support base and temperature-sensing elements.
The document includes one numbered figure, Figure 101, showing the wood block used in the mechanical test, and Table 12, which sets the pull force and torque for cord testing. It also contains marking and instruction requirements, construction rules for screens, insulation and cut-outs, and references to the applicable annexes of Part 1.
Relations
- Effective Date
- 01-Apr-2025
- Effective Date
- 01-Apr-2025
- Effective Date
- 01-Apr-2025
- Effective Date
- 01-Apr-2025
- Effective Date
- 09-Feb-2026
- Effective Date
- 18-Aug-2026
- Effective Date
- 18-Aug-2026
- Effective Date
- 07-Apr-2025
Frequently Asked Questions
EN IEC 60335-2-66:2026 is a standard published by CLC. Its full title is "Household and similar electrical appliances - Safety - Part 2-66: Particular requirements for water-bed heaters". This standard covers: This European Standard deals with the safety of electric water-bed heaters and their associated control units, for household and similar purposes, their rated voltage being not more than 250 V, including direct current (DC) supplied appliances.
This European Standard deals with the safety of electric water-bed heaters and their associated control units, for household and similar purposes, their rated voltage being not more than 250 V, including direct current (DC) supplied appliances.
EN IEC 60335-2-66:2026 is classified under the following ICS (International Classification for Standards) categories: 97.100.10 - Electric heaters. The ICS classification helps identify the subject area and facilitates finding related standards.
EN IEC 60335-2-66:2026 has the following relationships with other standards: It is inter standard links to EN 60335-2-66:2003/A11:2019, EN 60335-2-66:2003/A1:2008, EN 60335-2-66:2003, EN 60335-2-66:2003/A2:2012, EN ISO 2439:2008, EN 12976-1:2017, EN 12976-1:2021, EN IEC 60335-2-66:2026/A11:2026. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
EN IEC 60335-2-66:2026 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
Nadomešča:
SIST EN 60335-2-66:2003
SIST EN 60335-2-66:2003/A1:2008
SIST EN 60335-2-66:2003/A11:2019
SIST EN 60335-2-66:2003/A2:2012
Gospodinjski in podobni električni aparati - Varnost - 2-66. del: Posebne zahteve
za grelnike vodnih postelj
Household and similar electrical appliances - Safety - Part 2-66: Particular requirements
for water-bed heaters
Sicherheit elektrischer Geräte für den Hausgebrauch und ähnliche Zwecke - Teil 2-66:
Besondere Anforderungen für Wasserbett-Beheizungen
Appareils électrodomestiques et analogues - Sécurité - Partie 2-66: Exigences
particulières pour les dispositifs de chauffage pour matelas à eau
Ta slovenski standard je istoveten z: EN IEC 60335-2-66:2026
ICS:
13.120 Varnost na domu Domestic safety
97.030 Električni aparati za dom na Domestic electrical
splošno appliances in general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EUROPEAN STANDARD EN IEC 60335-2-66
NORME EUROPÉENNE
EUROPÄISCHE NORM August 2026
ICS 97.100.10 Supersedes EN 60335-2-66:2003; EN 60335-2-
66:2003/A1:2008; EN 60335-2-66:2003/A2:2012; EN
60335-2-66:2003/A11:2019
English Version
Household and similar electrical appliances - Safety - Part 2-66:
Particular requirements for water-bed heaters
(IEC 60335-2-66:2025)
Appareils électrodomestiques et analogues - Sécurité - Sicherheit elektrischer Geräte für den Hausgebrauch und
Partie 2-66: Exigences particulières pour les dispositifs de ähnliche Zwecke - Teil 2-66: Besondere Anforderungen für
chauffage pour matelas à eau Wasserbett-Beheizungen
(IEC 60335-2-66:2025) (IEC 60335-2-66:2025)
This European Standard was approved by CENELEC on 2026-07-27. 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.
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 CENELEC 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 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.
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.
Ref. No. EN IEC 60335-2-66:2026 E
European foreword
This document (EN IEC 60335-2-66:2026) consists of the text of document IEC 60335-2-66:2025,
prepared by IEC/TC 61 "Safety of household and similar electrical appliances".
The following dates are fixed:
• latest date by which this document has to be (dop) 2027-08-31
implemented at national level by publication of an
identical national standard or by endorsement
• latest date by which the national standards (dow) 2029-08-31
conflicting with this document have to be withdrawn
This document supersedes EN 60335-2-66:2003 and all of its amendments and corrigenda (if any).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.
This document is read in conjunction with EN IEC 60335-2-66:2026/A11:2026.
Any feedback and questions on this document should be directed to the users’ national committee. A
complete listing of these bodies can be found on the CENELEC website.
Endorsement notice
The text of the International Standard IEC 60335-2-66:2025 was approved by CENELEC as a European
Standard without any modification.
In the official version, for Bibliography, the following note has to be added for the standard indicated:
IEC 60601 (series) NOTE Approved as EN 60601 (series)
IEC 60335-2-66 ®
Edition 3.0 2025-02
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Household and similar electrical appliances – Safety –
Part 2-66: Particular requirements for water-bed heaters
Appareils électrodomestiques et analogues – Sécurité –
Partie 2-66: Exigences particulières pour les dispositifs de chauffage pour
matelas à eau
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 97.100.10 ISBN 978-2-8327-0233-8
– 2 – IEC 60335-2-66:2025 © IEC 2025
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 7
4 General requirement . 7
5 General conditions for the tests . 7
6 Classification . 8
7 Marking and instructions . 8
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 . 10
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 . 12
23 Internal wiring . 12
24 Components . 12
25 Supply connection and external flexible cords . 13
26 Terminals for external conductors . 13
27 Provision for earthing . 13
28 Screws and connections . 14
29 Clearances, creepage distances and solid insulation . 14
30 Resistance to heat and fire . 14
31 Resistance to rusting . 14
32 Radiation, toxicity and similar hazards . 14
Annexes . 16
Bibliography . 17
Figure 101 – Wood block . 15
Table 12 – Pull force and torque . 13
IEC 60335-2-66:2025 © IEC 2025 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
HOUSEHOLD AND SIMILAR ELECTRICAL APPLIANCES –
SAFETY –
Part 2-66: Particular requirements for water-bed heaters
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and
in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports,
Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their
preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with
may participate in this preparatory work. International, governmental and non-governmental organizations liaising
with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for
Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence between
any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
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
respect thereof. As of the date of publication of this document, IEC had not received notice of (a) patent(s), which
may be required to implement this document. However, implementers are cautioned that this may not represent
the latest information, which may be obtained from the patent database available at https://patents.iec.ch. IEC
shall not be held responsible for identifying any or all such patent rights.
IEC 60335-2-66 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:
2008 and Amendment 2:2011. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) alignment with IEC 60335-1:2020;
b) conversion of some notes to normative text (Clause 1, 19.4, 22.101);
c) clarification of requirements for remote operation (22.40, 22.49, 22.51).
– 4 – IEC 60335-2-66:2025 © IEC 2025
The text of this International Standard is based on the following documents:
Draft Report on voting
61/7249/CDV 61/7356/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 water-bed 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 states "addition", "modification" or "replacement", the
relevant text in Part 1 is to be adapted accordingly.
NOTE 2 The following numbering system is used:
– subclauses, tables and figures that are numbered starting from 101 are additional to those in Part 1;
– unless notes are in a new subclause or involve notes in Part 1, they are numbered starting from 101, including
those in a replaced clause or subclause;
– additional annexes are lettered AA, BB, etc.
NOTE 3 The following print types are used:
– requirements: in roman type;
– test specifications: in italic type;
– notes: in small roman type.
Words in bold in the text are defined in Clause 3. When a definition concerns an adjective, the adjective and the
associated noun are also in bold.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the
specific document. At this date, the document will be
• reconfirmed,
• withdrawn, or
• revised.
NOTE 4 The attention of National Committees is drawn to the fact that equipment manufacturers and testing
organizations can need a transitional period following publication of a new, amended or revised IEC publication in
which to make products in accordance with the new requirements and to equip themselves for conducting new or
revised tests.
IEC 60335-2-66:2025 © IEC 2025 – 5 –
INTRODUCTION
It has been assumed in the drafting of this International Standard that the execution of its
provisions is entrusted to appropriately qualified and experienced persons.
Guidance documents concerning the application of the safety requirements for appliances can
be accessed via TC 61 supporting documents on the IEC website.
https://www.iec.ch/tc61/supportingdocuments
This information is given for the convenience of users of this International Standard and does
not constitute a rep
...