MID Directive: thermal energy meters presumed conforming under EN 1434-1, -2, -4, -5 and -6:2022 (requirements, pattern approval, initial verification, installation) from 25 September 2025; for turbine gas meters EN 12261:2024 and volume conversion devices EN 12405-1:2021 — the 2018 editions lose the presumption on 27 August 2026
Commission Implementing Decision (EU) 2025/1939, published on 25 September 2025 and in force from the day of publication, adds five parts of EN 1434:2022 on thermal energy meters to Annex I to Decision 2021/1402 (harmonised standards for Directive 2014/32/EU on measuring instruments). The earlier Decision 2025/375, published on 27 February 2025, replaced in the same list the standards for turbine gas meters and gas volume conversion devices with their new editions. An instrument conforming to a harmonised standard published in the Official Journal is presumed to meet the essential requirements of the directive.
- Thermal energy meters — new rows 9–13 in Annex I to Decision 2021/1402: EN 1434-1:2022 (general requirements), EN 1434-2:2022 (constructional requirements), EN 1434-4:2022 (pattern approval tests), EN 1434-5:2022 (initial verification tests) and EN 1434-6:2022 (installation, commissioning, operational monitoring and maintenance). The decision does not list Part 3 of the standard. CEN drafted the standards under standardisation request C(2015) 8558; the Commission together with CEN assessed their compliance with the request.
- Scope of EN 1434 (EVS catalogue): thermal energy meters measure the energy absorbed (cooling) or given up (heating) in a heat-exchange circuit by a heat-conveying liquid and indicate it in legal units; the standard covers closed systems only, with limited differential pressure over the thermal load, and excludes electrical and pressure safety requirements and surface-mounted temperature sensors. The 2022 editions (in EVS from 15 September 2022) replaced EN 1434-1:2015+A1:2018 and EN 1434-5:2015+A1:2019.
- Gas meters (Decision 2025/375): EN 12261:2024 (turbine gas meters, row 2a) replaces EN 12261:2018, and EN 12405-1:2021 (conversion devices — volume conversion, row 3a) replaces EN 12405-1:2018. The deletion of the old rows 2 and 3 applies from 27 August 2026, to give manufacturers time to move to the new editions. According to EVS, EN 12261:2024 covers class 1.0 turbine gas meters with mechanical indicating devices for gases of the 1st and 2nd families (EN 437:2021), up to 420 bar and 25,000 m³/h, and also lists the Pressure Equipment Directive 2014/68/EU.
- EN 12405-1:2021 (EVS catalogue) specifies requirements and tests for electronic gas-volume conversion devices associated with gas meters, for type testing only, in three kinds of conversion: as a function of temperature only (T), of pressure and temperature with a constant compression factor (PT), and of pressure, temperature and the compression factor (PTZ). Both decisions enter into force on the day of publication, because the presumption of conformity runs from publication of the standard’s reference in the Official Journal.