Water meter

Water meter is a measuring instrument for a continuous measurement, recording and display of the volume of water flowing through it on standardized working conditions.

Pursuant to the Public Water Supply and Sewerage Act (§ 15), the water sold to the customer from the public water supply system must be measured by means of water meter. The installation of a water meter is an obligation of the water undertaking.

AS Tallinna Vesi shall install the main water meter in a properly built water metering unit of a customer and shall perform further maintenance and verification of the water meter at company’s expense, except if the water meter is damaged or stolen on customer’s fault. Upon termination of the service contract (incl. temporary suspension), we will dismantle the water meter free of charge.

Additional water meters (incl. water meters and hot water meters installed in apartments) usually belong to the customer and we do not perform or offer any control, verification or repair on these meters.

The size of a water meter and the nominal flow will be selected based on the average consumption of water per hour. In the detached buildings, DN 15 and DN 20 water meters are installed, with a nominal flow of 1.5 m3/h and 2.5 m3/h, respectively. Choosing a water meter, based on the average consumption of water per hour:

Nominal water consumption, m3/h 1.5 2.5 3.5 10.0
Water meter gauge, inches (mm) 1/2 (15) 3/4 (20) 1 (25) 11/2 (40)


The water meters in use are equipped with a sieve. In case of a pressure drop or a blockage, we will clean the sieve or replace the water meter.

Control and verification of water meters

AS Tallinna Vesi must, in accordance with the Regulation No 65 of 01.01.2019 by the Minister of Economic Affairs and Infrastructure, verify all the main water meters in every 5 years, by removing the old water meter and installing a new, recently calibrated water meter on a site. The new water meter may have been previously in use, i.e. may have been removed from another site. All water meters shall be controlled, repaired, if necessary, and verified before any new installation. The process of controlling and verifying the water meters is performed on a special test bed, without any human intervention. Verification is carried out by AS Metrosert.

In case of any doubts, the customer is entitled to request an expertise, i.e. extra verification. If the expertise is performed elsewhere, then the customer must inform us beforehand, so that our employee can remove the water meter and install a new meter on the site. All the costs related to any external expertise shall be covered by the customer. Application for expertise (EST) is available here.

If the expertise is requested from us, then the client may choose to be present during the expertise. The expertise of water meters shall be conducted on a special test bed, allowing to determine the measuring error of a water meter in accordance with the standards within 3 flow points:

  • Qmin (Q1) – the smallest flow value, below which the water meter error is not limited. Permissible range of measuring error for cold water meters is ≤ +/- 10%;
  • Qt (Q2) transition flow – this is a flow value, below which the water meter error is +/-5%. Permissible range of measuring error for cold water meters is ≤ +/- 4%;
  • Qn (Q3) nominal flow – this is the highest flow of a given meter at which the water meter may work continuously. Permissible range of measuring error for cold water meters is ≤ +/- 4%;

Note: Different symbols for flow values described above are due to the different standards, according to which the water meter is manufactured.

The customer does not have to pay for the expertise, if the water meter was incorrect (i.e. the measuring error exceeded the permissible limits). If the water meter was correct (i.e. the measuring error remained within the permissible limits), the customer shall have to pay for the expertise.

If the expertise reveals that:

  • the measuring error of the water meter exceeds the permissible limit in at least one of the points (i.e. to the detriment of the customer), then the customer does not need to pay for the expertise and we shall make a settlement for the water consumption of the last 6 calendar months based on the percentage of measuring error, incl. the calendar month when the measuring accuracy was controlled, until the new meter is installed;
  • the measuring error of the water meter is proved to be negative (i.e. for the benefit of the customer), then the customer does not have to pay for the expertise, neither will he be asked to pay any extra.

Customer must protect the water meter (Rules on the Use of PWSS in Tallinn):

Customer’s responsibility is to ensure the functioning of the water meter. Customer shall ensure that:

  • the water meter is kept intact and protected from freezing and overheating;
  • the premises of the water metering unit and the metering chamber are tidy, clean and dry, and the premises are illuminated;
  • the fittings of the water metering unit are in running order;
  • the water meter is not flooded by the water flowing into the premises or the chamber.

The customer’s responsibility is to inform us immediately of any failures or damages of the water meter.