A tap that starts spitting and spluttering when opened is one of the most common minor annoyances in apartments and detached houses in Tallinn and Harjumaa, raising questions among owners – is something broken, has the water quality deteriorated, or is it a warning sign?
In reality, the reason is usually quite simple and harmless – air has entered the pipework, which is then expelled with the water when the tap is opened. This creates a characteristic spluttering, spitting sound, and sometimes foamy water, which initially seems worrying but is actually a physical phenomenon that usually dissipates quickly.
In this guide, we will thoroughly explain why air enters the pipework, how to safely and quickly remove it yourself, the role of the aerator (the mesh screen on the tap nozzle), and when spluttering water should make you cautious and prompt you to contact a specialist.
We will also examine specific situations – conditions after a water outage, the first-time filling of a new apartment or house water system, properties with booster pumps, and specific cases involving water heaters and mixers – so you can quickly identify your situation and know what steps to take.
What Exactly Happens When Air Enters the Pipework?
In normal conditions, the water pipework is a closed system completely filled with water and under pressure, where air should not be present. However, if air enters the system for any reason – for instance, during pipe repairs, a water outage, or the installation of new equipment – air bubbles or longer air pockets form in the pipes.
When you then open the tap, the pump or water network pressure pushes not only water but also these air bubbles through the pipe. Air and water move together, and since air is compressible, it expands sharply at the tap nozzle, creating a characteristic spluttering, spitting, and sometimes rattling sound.
This is why water splutters from the tap – the mixture of water and air does not flow in a steady stream through the pipe, but rather in intermittent bursts, which are dispersed in various directions at the tap's small opening.
- A small amount of air causes a short, few-second splutter that quickly disappears.
- A larger air pocket in the pipe can cause several spluttering bursts in a row until all the air has escaped.
- Sometimes, spluttering is accompanied by temporary cloudiness or a whitish tint to the water – this is also due to air bubbles, not dirt (read more below).
When Does Air Enter the Water Pipework?
To prevent the problem or understand its recurrence, it's useful to know the most common reasons why air enters the pipework.
- Water outage – if the water company temporarily cuts off the water supply (e.g., for pipe repairs), the pipe partially empties, and when the water network is restored, air enters the system, which must vent from the pipe before a stable flow is achieved.
- Pipe repairs or replacement – when water pipes, shut-off valves, or fittings are replaced in a house or apartment, the system is inevitably opened, allowing air to enter, which must be removed from the system after the work is complete.
- Installation of a new water meter – during meter replacement, shut-off valves are closed and opened, allowing air to enter the system.
- Water heater or pressure tank maintenance and draining – if a water heater or hydrophore is drained for maintenance, it partially fills with air when reconnected, which then moves into the pipework.
- First-time filling of an entire house's water system – in a new build or after a long period of inactivity (e.g., a summer home in winter), the entire pipework is filled at once, and air must vent sequentially through all taps.
- Booster pump activation or restart – if a pump has been idle or there's been a power cut, when the pump restarts, air may remain in the pipework before the pump system and water pipes are fully refilled and pressure stabilises.
- Low water level in a well or tank – in detached houses where water comes from a shallow well or borehole, if the water level is low, the pump may draw air along with the water, which then carries into the entire house system.
Tap Splutters After a Water Outage – Is This Normal?
This is the most common situation where people worry about spluttering water, but it's also the most typical and predictable cause.
If the water company has announced a planned water outage for pipe repairs or maintenance, the affected pipe section partially empties. When the water supply is restored, water is forced back into the pipe, which first passes through a section containing air before fully filling.
In such a situation, it is entirely normal for the water coming from taps to be spluttering, spitting, whitish, or full of air bubbles for the first few minutes or even hours after the water outage ends – this will disappear on its own as the pipework fully refills with water.
How long does this usually last?
In a small apartment with short pipework, normal water flow usually resumes within a few minutes after opening and closing the first few taps. In a larger house or building with longer pipework, it can take up to several hours, especially if air needs to be removed from all floors and branches.
First-Time Filling of a New House or Renovated Apartment's Water System
In new builds and extensively renovated apartment buildings, the entire water pipework is drained before commissioning – meaning that upon the system's first filling, the pipes initially contain only air, which the water must displace.
This process usually takes longer than in a typical situation with a smaller air pocket, as the entire volume of the pipework needs to be purged of air. Builders and plumbers are aware of this process and usually run all taps, showers, and cisterns sequentially until the flow is steady and the air is gone.
If you have just moved into a new apartment or your building has completed pipe replacement, a few days of spluttering and spitting from the tap is a completely natural phenomenon that will disappear within a couple of days with active use.
Properties with Booster Pumps – How Does the Pump Affect the Air Problem?
Many taller apartment buildings and some detached houses use a booster pump, which increases the pressure of the water from the mains so that it reaches upper floors with sufficient pressure.
If the pump has been idle – for example, due to a power cut, maintenance, or a fault – it may draw air into the pipework when it restarts, before the pump system and water pipes are fully refilled and the pressure stabilises. In such a situation, spluttering and pressure fluctuations occur throughout the entire building, not just in one apartment.
If spluttering water occurs simultaneously in several apartments and the problem persists for more than half a day, it's advisable to inform the apartment association or building manager – it may be necessary for a specialist to bleed the pump system directly at the pump station.
- Single apartment, single tap – likely localised air, resolved by bleeding the tap.
- Multiple apartments simultaneously, including on different floors – likely a booster pump or riser issue, requiring a building-level solution.
The Role of the Aerator – Why Does the Tap Nozzle Amplify Spluttering?
The aerator, a small mesh component screwed onto the tap nozzle, is designed to mix the water jet with air to reduce water consumption while making the water flow smoother and softer. In normal conditions, the aerator helps make water use more economical and comfortable.
However, if there is excessive air in the pipework, the aerator receives more air than it is designed to handle, causing the flow to become intermittent and spluttering – the aerator effectively amplifies the effect of air bubbles, as it directs the exiting water jet through many small openings, which, with expanding air, cause wider spluttering.
Without an aerator, the flow might still be intermittent, but spluttering is usually less noticeable, as water flows through a larger, more uniform opening.
Can the aerator itself cause the problem?
Yes – over time, limescale, sand, and small dirt particles accumulate in the aerator's fine mesh, reducing its flow capacity. A partially blocked aerator can cause spluttering and an uneven flow even if there are no air bubbles in the pipework – in this case, the problem won't disappear on its own but requires cleaning or replacing the aerator.
How to Distinguish Between Air-Induced Spluttering and a Blocked Aerator?
Since both situations result in spluttering and an uneven water flow, it's useful to know how to differentiate between the two causes.
- Air in the pipes – spluttering is stronger in the first few seconds of opening the tap and gradually diminishes or disappears after letting the water run for a few minutes; often accompanied by whitish or milky water that clears within seconds.
- Blocked aerator – spluttering and an uneven flow are persistent and do not improve over time, the directions of the jet are uneven and sometimes misdirected, and the problem occurs consistently every time you open the tap, not just after a water outage or repair.
- If the water flow is even and strong when the aerator is removed (the aerator is unscrewed by hand from the tap nozzle), the problem is definitely with the aerator, not the pipework.
Why Does the Water Look White or Milky When It Comes From the Tap?
Besides spluttering, many people notice that water appears cloudy, whitish, or milky when filling a glass. This often causes more alarm than spluttering itself, but it is also a sign of air, not dirt.
The white tint occurs because small air bubbles are dissolved in the water – these scatter light and make the water appear cloudy. If you let a glass of water stand for a few minutes, the air bubbles will rise to the surface, and the water will clear from the bottom up, becoming normal clear drinking water.
If the water remains cloudy even after a few minutes of standing and does not clear, it is no longer due to air but actual impurities or sediment – in this case, it is advisable to contact the water company or a plumber regarding water quality (read more in our article on yellow water from the tap).
What Can You Do Yourself If the Tap Splutters?
In most cases, air can be easily removed from the pipework yourself, without the need for a specialist. Proceed as follows:
- Open the tap fully and let the water run for a few minutes – most air usually exits within the first 1–5 minutes.
- If your tap has an aerator, unscrew it and let water flow through the exposed nozzle – this will release air faster and allow you to check if the aerator needs cleaning.
- Start with the lowest tap in the house or apartment (e.g., the kitchen tap) and gradually move to taps on upper floors – air tends to accumulate at higher points and eventually exits with the water flow.
- Also check shower and bath mixers, as these typically have a wider outlet than standard taps and allow air to exit faster.
- If there's a water heater in the house, also let hot water run from it for a few minutes – there might be separate air pockets in the water heater itself.
- If the water is cloudy, let a glass stand for a few minutes and see if it clears from the bottom – this confirms it was due to air.
How to Clean the Aerator If Spluttering Persists?
If spluttering does not decrease after a few minutes of flowing and the flow remains uneven, it's worth unscrewing and cleaning the aerator.
- Unscrew the aerator by hand or, if necessary, with pliers (gently, wrapped in a cloth to avoid scratching the surface) from the tap nozzle.
- Rinse the aerator under running water and remove any visible dirt and limescale.
- If limescale is stubbornly hardened, soak the aerator for half an hour to an hour in a diluted vinegar solution, which dissolves calcium deposits.
- If needed, use a soft brush (such as an old toothbrush) to clean the fine mesh and opening parts.
- Rinse thoroughly and screw the aerator back onto the tap.
Does Spluttering From a Water Heater Tap Differ From a Cold Water Tap?
In households with a water heater, air can also accumulate within the hot water tank itself, not just the pipes – meaning that spluttering from the hot water tap may last longer or be more intense than from the cold water tap.
This is especially likely after water heater maintenance, sediment removal, heating element replacement, or a prolonged water outage during which the water heater has partially drained and then been refilled.
When Should You Be Concerned About a Water Heater?
If hot water spluttering is accompanied by a continuous gurgling sound from the water heater itself, unusual odours, or sudden temperature fluctuations in the water, it's advisable to call a specialist to inspect the water heater – this could indicate other problems, such as a faulty heating element (read more in our article on signs of water heater element issues).
How Long Can Spluttering Last Before It's Concerning?
With a typical air problem, spluttering and cloudiness should disappear within minutes to a few hours, depending on the length of the pipework and the amount of air.
- Under 15 minutes – perfectly normal for a single tap after a brief water outage.
- A few hours – normal for an entire house or long pipework after a prolonged outage or repair.
- 1–2 days – possible when filling a new system for the first time, but a diminishing trend should be observed.
- More than several days without improvement, or a problem that doesn't resolve even with careful bleeding and aerator cleaning – in this case, there's reason to suspect another problem, such as a pump malfunction, pipe damage, or a partially blocked shut-off valve, and you should contact a specialist.
Are the Causes Different in Apartment Buildings and Detached Houses?
Although air in the pipework is the same physical phenomenon in both cases, typical causes and solutions vary depending on the building type.
Apartment Buildings
In an apartment building, spluttering is often affected by the building's common pipework, booster pump, and maintenance work carried out by the apartment association. If the problem affects several apartments simultaneously, the solution is usually building-wide and requires intervention from the association or manager. If the problem is only in your apartment, bleeding your own taps is usually sufficient.
Detached Houses
In a detached house, especially if water comes from a shallow well or borehole, spluttering can also indicate a low water level in the well, causing the pump to draw air along with the water. If the well's water level is low, the condition of the well should be checked, and if necessary, a well or borehole specialist should be contacted, as long-term air intake can damage the pump.
When Is It Time to Call a Plumber?
Most spluttering incidents can be resolved at home by bleeding and cleaning the aerator, but there are situations when it's advisable to call a specialist.
- Spluttering doesn't improve after several days, despite regular bleeding.
- Spluttering is accompanied by a persistent drop in water pressure or unusual noises in the pipes.
- The water remains cloudy even after several minutes of standing and does not clear.
- The problem occurs simultaneously in several apartments in an apartment building, indicating a building-wide issue.
- In a well-equipped detached house, unusual pump noise or frequent on/off cycling accompanies the problem.
- You suspect pipe damage, for example, after construction work or ground movement on the property.
How Can ToruFix OÜ Help?
If necessary, we will inspect the pipework and shut-off valves, professionally bleed the system at all points, clean or replace aerators and mixers, and identify whether the problem is due to a larger technical fault, such as a booster pump malfunction or pipe damage.
How to Prevent Spluttering in the Future?
Although air entering the pipework cannot always be completely avoided, some simple habits can reduce the frequency and severity of the problem.
- Clean aerators regularly, for example, a couple of times a year, to reduce limescale buildup.
- After a known water outage, first let the tap on the lowest floor run for a few minutes before using other appliances like washing machines or dishwashers.
- If you plan a longer absence, close the main stopcock to prevent the system from draining and air entering.
- In a detached house, monitor the well's water level regularly, especially during dry summer periods.
- In an apartment building, notify the manager immediately if you notice spluttering in several apartments simultaneously – early notification helps prevent long-term damage to the pump.