Heat Meter Re-verification and Calibration
Heat meters must be re-verified at intervals set by national legislation (every 5 years in Türkiye). Use the metrology marking to find when your meter is due; in Türkiye we run the whole process for you, including removal, transport, reinstallation and commissioning.
When Is Your Meter Due for Re-verification?
Look at the metrology marking on the front of the meter: the two digits after the letter M show the year the meter was marked (e.g. M21 = 2021). For meters that have already been re-verified, the year of the last verification mark applies. That year counts as year one; the meter is due once the re-verification interval has ended. In Türkiye, applications are made in January–February of the following year.
| Marking / verification year | 5-year period | Due | |
|---|---|---|---|
| M19 · 2019 | 2019–2023 | 2024 | |
| M20 · 2020 | 2020–2024 | 2025 | |
| M21 · 2021 | 2021–2025 | 2026 | |
| M22 · 2022 | 2022–2026 | 2027 | |
| M23 · 2023 | 2023–2027 | 2028 | |
| M24 · 2024 | 2024–2028 | 2029 | |
| M25 · 2025 | 2025–2029 | 2030 | |
| M26 · 2026 | 2026–2030 | 2031 |
Example for a 5-year re-verification interval, as required in Türkiye. Intervals and application periods differ by country; check your local regulations for periodic re-verification requirements.
How Is a Heat Meter Re-verified?
- 1Application
When its period has expired, the meter is submitted to an authorized verification service within the period set by national rules.
- 2Seal check
Seals and verification marks must be intact; if tampering is found, the meter cannot be re-verified.
- 3Test
The meter is measured on a reference test rig under different conditions: flow, temperature and calculation accuracy (EN 1434-5).
- 4Evaluation
The measured heat energy is compared with the value calculated by the meter; the error in percent is compared with the maximum permissible error (MPE) limits.
- 5Result
A meter within the limits receives a verification mark. If it exceeds them, a non-conformity report is issued and the meter is repaired and adjusted, or replaced.
Let Us Handle the Re-verification
Re-verification is carried out by authorized verification services. In Türkiye, Novus Energy takes care of all on-site work, from removing your meters to reinstalling them:
- Removal and transport of the meters
- Draining and refilling the system
- Reinstallation and commissioning after re-verification
- Calibration and battery replacement if needed
- Replacement of meters that cannot be corrected by calibration
- Recording the final reading of the removed meter and the initial reading of the new one
Re-verification Fees
Official fees cover only re-verification and marking. Removal, installation, transport, automation connections, calibration, battery replacement and repairs are charged separately.
What Happens If a Meter Is Not Re-verified?
Depending on national legislation, using heat meters that have not been re-verified or whose verification period has expired can lead to administrative fines. A meter that fails re-verification is repaired and adjusted where possible; if repair is not possible, it must be replaced.
Re-verification or a New Meter?
If your meter is old, its battery is low, or the cost of re-verification plus removal and reinstallation comes close to the price of a new meter, installing a new heat meter may be more practical. The re-verification period of a new meter starts from the year on its metrology marking. Models matching the size of your existing meter:
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Frequently Asked Questions
How often must a heat meter be re-verified?
The interval is set by national legislation and differs by country; in Türkiye it is 5 years. The period is counted in years: the year in which the meter was marked counts as year one, whatever the month.
When should the re-verification application be made?
Application periods are set by national rules. In Türkiye, the application is made from the start of January to the last day of February of the year after the period ends; for example, for a meter marked in 2021 (M21), the application period is January–February 2026.
How much does heat meter re-verification cost?
Official re-verification fees are set by national tariffs and usually depend on meter size. They cover only re-verification and marking; removal, installation, transport, calibration, battery replacement and repairs are charged separately.
What happens to a meter that fails re-verification?
A non-conformity report is issued for a meter that exceeds the error limits. The meter is repaired and adjusted where possible; if repair is not possible, it must be replaced.
What happens if a heat meter is not re-verified?
Depending on national legislation, using heat meters that have not been re-verified or whose verification period has expired can lead to administrative fines.
Are your meters due for re-verification?
Let us plan the re-verification schedule for your building or residential complex and clarify the process and costs.