In short: When no water is needed in the household, the water meter should also stand still. With a photo, 15 minutes of stillness and a second meter reading, a continuous trickle can often be detected early. This does not replace professional leak detection, but it provides a clear indication of whether you should take a closer look.
In Austrian households, an average of around 130 liters of drinking water per person per day is used. According to Federal Ministry for Agriculture and Forestry, Climate and Environmental Protection, Regions and Water Management a large share is accounted for by toilet flushing, personal hygiene and the kitchen. An unnoticed continuous loss is particularly significant: the City of Vienna gives guideline values of about 36 liters per day for a slightly dripping tap and around 700 liters for a slightly running toilet flush.
The 15-minute test at the water meter
Choose a period during which no one really needs water. In an apartment building you must first clarify whether the accessible meter only records your flat or the entire building. A shared main meter is not suitable for a clear test of your apartment.
- All water users paused: Turn taps fully off. Washing machine and dishwasher must not be running. Also check toilets, irrigation, boiler make-up water and other appliances with a water connection.
- Photograph the first reading: Photograph the entire meter so that the meter number, number dials and small pointers or control wheels are visible. Note the time. Do not touch any seal and do not adjust anything on the meter.
- Don't use any water for 15 minutes: Not even a toilet flush or quick handwashing. Watch whether a small control wheel or a pointer moves. For very small losses, comparing photos is more reliable than a quick glance.
- Compare the second reading: If the reading has increased, repeat the test once under the same conditions. This rules out that a device had used water.
Interpreting the result correctly: If the meter stays still, this speaks against a continuous loss during this time window. However, it does not exclude a problem that occurs only intermittently. If it moves again even though no water is certainly being used, the cause should be narrowed down and professionally inspected.
How much water is lost?
If your meter shows liters or decimal places in cubic meters, you can roughly extrapolate a steady loss. One cubic meter equals 1,000 liters. For a 15-minute test: measured liters times 96 give the theoretical daily loss.
- 0.1 liters in 15 minutes correspond to about 9.6 liters per day.
- 0.5 liters correspond to about 48 liters per day.
- 1 liter corresponds to about 96 liters per day.
- 5 liters correspond to about 480 liters per day.
This is only a snapshot. Toilet flushes can, for example, run on intermittently, and appliances draw water in intervals. Therefore note not only an extrapolation but also the time and test conditions. The Austrian study on household water consumption provides current comparison values; however, more important than an average is an unusual jump in your own comparable consumption.
Check four typical locations
1. Toilet cistern
Wait after flushing until the cistern is completely filled. Then watch for a faint hissing sound, movement on the water surface, or a narrow film of water on the rear inner wall of the toilet bowl. A dry layer of toilet paper in this spot will quickly become wet if water is constantly running. With a concealed cistern or unclear operation you should not disassemble anything, but inform the property management, landlord or plumbing company.
2. Fixtures and angle valves
Check not only the spout but also the area under the washbasin and sink. Damp edges, lime deposits, swollen wood or a musty smell can indicate a slow leak. Wipe suspicious areas dry and check again later. Replacing an old seal yourself only makes sense if you can reliably shut off the water supply and are familiar with the fixture. Otherwise a professional is the better choice.
3. Appliance connections
Check hoses, fittings and the floor underneath washing machine, dishwasher and refrigerators with a water connection. Do not pull heavy appliances forward alone and do not reach into moisture near electrical connections. Disconnect the power only if it can be done safely, shut off the known water supply and get help.
4. Outdoor connections and irrigation
A garden valve that is not fully closed or a leaking irrigation line can also affect the meter test. Explicitly check timers and automatic systems before assuming a leak in the building. For water-saving watering you can find additional tips on Watering and mulching during heat.
When you should act immediately
If water is visibly leaking, walls are wet, a ceiling is bulging or water is near electrical installations: protect people and quickly get professional help. Close a shut-off only if you know exactly which one it is and it can be reached safely. For rental properties, property management or the landlord should be informed early; if damage occurs before the water meter, the local water supplier is responsible. The exact boundary may vary regionally.
A moved meter alone without visible damage is not a reason to open pipes on your own. Document both readings, times and all paused consumers. This information helps a plumbing company with the narrowing down. The City of Vienna also states that a water meter should stand still when consumption is completely at rest; you can find current service centers from your respective supplier.
A simple routine for the future
- Photograph the meter once a month at approximately the same time of day.
- Compare not only euro amounts but also cubic meters and the billing period.
- Repeat the stillness test if consumption increases for no explainable reason.
- Check visible connections before longer absences. Our Vacation check for the apartment.
- Remember where the relevant shut-off valve is, without trying to operate it forcefully.
If the meter stands still and you want to reduce normal consumption, start with frequent uses rather than individual drips: take shorter showers, turn off water while soaping and only run appliances when fully loaded. The City of Vienna in its water-saving tips.
Frequently asked questions about the water meter test
Are 15 minutes really enough?
Often yes for a constant loss. For very small or intermittent leaks, a longer comparison makes sense, for example overnight. WC, appliances, irrigation and all other consumers must be guaranteed to be paused for that.
What does a small spinning wheel mean?
Many meters have a sensitive flow indicator. If it moves repeatedly during complete consumption rest, water is probably flowing somewhere. The exact indication principle differs by meter type; therefore follow your supplier's instructions.
May I open the water meter myself?
No. Read and photograph it only from the outside. Seals, connections and the measuring device itself must remain untouched. The supplier is responsible for meter questions, and for pipes and fittings after the meter generally a plumbing company or the property management.
