EU Updates Thermal Energy Meter Standards Under New Commission Decision

The European Commission has adopted Implementing Decision (EU) 2025/1939 on 24 September 2025, updating harmonised standards for thermal energy meters across the European Union. This amendment to Implementing Decision (EU) 2021/1402 establishes clearer compliance pathways for manufacturers under Directive 2014/32/EU.

What the Amendment Changes

The amendment updates the list of harmonised standards that thermal energy meters must meet for presumed compliance with Directive 2014/32/EU requirements. The new standards are:

EN 1434-1:2022 (General requirements): Establishes fundamental operational conditions, technical characteristics, measurement ranges, heat transmission formulas, and environmental classifications for thermal energy meters measuring energy absorbed or released in heat-exchange circuits.

EN 1434-2:2022 (Constructional requirements): Defines physical design specifications including temperature sensor dimensions, probe types, mounting configurations, and structural requirements for meters measuring thermal energy in closed systems with limited pressure differentials.

EN 1434-4:2022 (Pattern approval tests): Specifies comprehensive testing procedures and performance criteria to verify accuracy, reliability, and durability during the pattern approval process, ensuring meters meet regulatory standards before market authorization.

EN 1434-5:2022 (Initial verification tests): Details verification procedures including metrological, technical, and administrative phases to confirm manufactured instruments conform to approved patterns and operate within maximum permissible error limits.

EN 1434-6:2022 (Installation, commissioning, operational monitoring, and maintenance): Provides guidelines for proper installation, system commissioning checks, operational monitoring protocols, and maintenance procedures to ensure continued accurate performance throughout the meter's operational lifecycle.

These standards are now included in Annex I of Decision (EU) 2021/1402, consolidating requirements within a single legislative act.

European Standardisation Process

The revision follows a 2015 Commission request to the European Committee for Standardization (CEN), the European Committee for Electrotechnical Standardization (Cenelec), and the European Telecommunications Standards Institute (ETSI). CEN drafted the updated thermal energy meter standards, which the Commission assessed and confirmed meet Directive 2014/32/EU essential requirements.

Market Impact

Thermal energy meters manufactured according to these harmonised standards receive presumption of conformity with EU legal requirements for accuracy, safety, reliability, and operational effectiveness. This presumption takes effect from the publication date of standard references in the Official Journal of the European Union.

The consolidated standards create uniform evaluation criteria across the EU, supporting free movement of compliant goods in the Single Market and ensuring consistent energy measurement practices.

Implementation

Commission President Ursula von der Leyen signed the decision in Brussels, with immediate entry into force upon publication. Compliance with these harmonised standards immediately confers presumption of conformity with relevant requirements, providing regulatory certainty for manufacturers, importers, and regulatory bodies.

Context: Directive 2014/32/EU

Directive 2014/32/EU, the Measuring Instruments Directive (MID), sets rules for placing measuring devices including thermal energy meters on the market. It ensures instruments meet strict accuracy, reliability, and safety standards so results are trusted across all EU countries. Compliant devices receive CE marking and can be used throughout the EU without additional local approvals.