EN 50440:2015/A2:2026

• Abstract:

  This European Standard specifies methods for measuring the performance of electric storage water heaters for the production of sanitary hot water for household and similar use. The object is to state and define the principal performance characteristics of electric storage water heaters and to describe the test methods for measuring these characteristics. NOTE 1 This standard does not apply to; − storage water heaters that use electricity as a secondary source of heating the water; − storage water heaters that do not use a tank to store hot water; − electric storage water heaters that do not meet the minimum (or maximum) output performance of the smallest (or biggest) load profile, as defined in Table 4. NOTE 2 This standard does not specify performance or safety requirements. For safety requirements see EN 60335-1:2020 in conjunction with EN 60335-2-21:2023

• Status: Not Published
• Publication Date: 08-Oct-2026
• ICS: 91.140.65 - Water heating equipment
• Technical Committee: CLC/TC 59X - Consumer information related to household electrical appliances
• Drafting Committee: CLC/TC 59X/WG 04 - Water heaters
• Current Stage: 6055 - Ratification Completed (DOR) - Publishing
• Start Date: 31-Aug-2026
• Due Date: 31-Dec-2026
• Completion Date: 31-Aug-2026
• Ref Project: SIST EN 50440:2016/oprA2:2026 - Efficiency of domestic electrical storage water heaters and testing methods

• Amends: EN 50440:2015 - Efficiency of domestic electrical storage water heaters and testing methods
• Effective Date: 13-Aug-2024

Overview

EN 50440:2015/A2:2026 - Efficiency of domestic electrical storage water heaters and testing methods - is a European Standard developed by the CLC (European Committee for Electrotechnical Standardization, CENELEC). This standard specifies the methods for measuring and evaluating the performance characteristics of electric storage water heaters designed for producing sanitary hot water for domestic and similar uses. The document details standardized test methods to ensure reliable comparison and consistent assessment of efficiency for household electric water heaters.

Importantly, EN 50440:2015/A2:2026 focuses exclusively on performance measurement and does not address product safety requirements. For safety standards, reference should be made to EN IEC 60335-1 and EN IEC 60335-2-21.

Key Topics

• Scope and Applicability:
  • Applies to electric storage water heaters used to produce hot water for domestic use.
  • Excludes storage water heaters using electricity as a secondary source, tankless systems, and models outside defined output performance ranges.
• Performance Characteristics:
  • Clearly defines the principal performance metrics such as rated heat output, electric consumption, and efficiency.
• Testing Methods:
  • Describes detailed procedures for evaluating energy consumption, temperature patterns, and water delivery profiles under controlled conditions.
• Test Conditions:
  • Establishes reference and general test conditions, including cold/hot water temperature settings, ambient air parameters, and prescribed sampling intervals.
• Load Profiles:
  • Includes detailed schedules of water draw-off events (load profiles) which ensure consistent measurement for products of varying capacities.
  • Provides procedures for verifying manufacturer-declared load profiles against tested maximum or next-lower profiles.
• Reporting and Data Recording:
  • Specifies the format and key data points for test reports, including rated heat output and annual consumption estimates.

Applications

EN 50440:2015/A2:2026 is essential for:

• Manufacturers of electric storage water heaters looking to demonstrate product efficiency in compliance with European requirements.
• Testing laboratories and certification bodies performing standardized performance evaluations to support product claims and regulatory submissions.
• Policymakers and regulatory authorities setting minimum efficiency thresholds for domestic water heating appliances within the European market.
• Eco-design and energy labelling programs, where consistent measurement and classification of water heater efficiency is needed for consumer transparency and market surveillance.

Consistent application of this standard helps ensure that electric storage water heaters are evaluated in a uniform manner, supporting fair competition, consumer protection, and environmental policies.

Related Standards

• EN 60335-1:2020 – Safety of household and similar electrical appliances - General requirements
• EN 60335-2-21:2023 / EN IEC 60335-2-21 – Particular safety requirements for storage water heaters
• DIRECTIVE 2012/27/EU – Energy efficiency: reference for the conversion coefficient of electricity in primary energy

Practical Value

Adhering to EN 50440:2015/A2:2026 allows for:

• Accurate efficiency ratings that enable consumers to make informed choices based on product performance.
• Compliance with European energy efficiency regulations and eco-design requirements.
• Streamlined product testing and market entry across Europe by conforming to widely recognized and harmonized test methods.
• Benchmarking and product comparisons, facilitating the advancement of energy-efficient technologies in the domestic water heating industry.

By following this standard, organizations ensure that testing of domestic electric storage water heaters is reliable, repeatable, and aligned with European best practices for product efficiency evaluation.