Low water pressure in the tap is usually due to clogged aerators, partially closed valves or lime deposits in the piping system. You can increase the water pressure by cleaning the tap's aerator, checking that all valves are fully open and adjusting the pressure reducing valve if you have one. If the problem affects the whole property or several taps, you may need the help of a plumber to fix more extensive problems in the piping system.
Why is the water pressure low in my tap?
Low water pressure in the tap is usually due to clogged aerators, partially closed valves, lime deposits in the pipes or problems with the pressure reducing valve. In older houses, even the piping system itself can be the cause if the lines have become clogged with lime deposits over time. Identifying the right cause will help you choose the right remedy.
The most common cause is a clogged aerator in the faucet. The aerator is located at the end of the tap spout and easily collects limescale and dirt, reducing the flow of water. If the water jet comes out irregularly or splashes in different directions, it is a clear sign that the aerator needs cleaning.
Partially closed valves are another common cause that is often overlooked. Under the tap, usually in the cupboard under the sink or basin, there are small valves that control the water supply. If these are not fully open, you will get lower water pressure. Check that the valves are turned fully counter-clockwise for maximum flow.
Lime deposits in the piping system are more problematic and occur especially in hard water areas. The limescale gradually builds up on the inside of the pipes and reduces the water flow over time. This is often noticeable as gradual deterioration of water pressure throughout the apartment or house.
The pressure reducing valve may also need to be adjusted. This valve regulates the water pressure from the main pipe and is usually located where the water pipe enters the property. If the valve is misadjusted or faulty, it will affect the water pressure throughout the property.
How to clean a clogged aerator to improve water pressure?
Cleaning a clogged aerator takes only a few minutes and requires minimal equipment. You will need pliers or a wrench, a bowl of vinegar, an old toothbrush or small brush, and possibly a rag. The aerator is the small grate at the end of the faucet spout that you can unscrew counterclockwise.
Start by turning off the water under the tap to avoid spillage. Unscrew the aerator by turning it counterclockwise. If it's tight, you can use pliers, but wrap a cloth around the aerator to avoid scratching the surface. Carefully remove the aerator and note how the parts fit together so you can reassemble them correctly.
Place the aerator in a bowl of white vinegar and leave it for at least 30 minutes. The vinegar effectively dissolves lime deposits. For heavily soiled aerators, you can leave them overnight. After soaking, brush off any remaining lime and dirt with a toothbrush. Rinse thoroughly under running water.
Reassemble the aerator by screwing it clockwise. Do not overtighten as this may damage the threads. Turn the water back on and check that the water jet is even and powerful. If the problem persists, the aerator may be damaged to the extent that it needs replacing.
To improve water pressure in the long term, you should clean the aerator every three to six months, depending on how hard the water is in your area. Regular cleaning prevents limescale build-up and keeps the water pressure optimal.
Can I adjust the pressure reducing valve myself at home?
A pressure-reducing valve regulates the water pressure from the main line to a safe level for your house or apartment. The valve is usually located where the water pipe enters the property, often in the basement, storage room or under the sink in an apartment. You can adjust the valve yourself if you are careful, but for major interventions you should contact a plumber.
The pressure reducing valve has an adjusting screw or nut on top. Turning it clockwise increases the water pressure, and turning it counterclockwise decreases it. Make small adjustments at a time, about a quarter turn, and then test the water pressure in the taps. Normal residential water pressure is between 2.5 and 4.5 bar.
Before adjusting the valve, you should check the current pressure with a manometer if possible. Too high a pressure can damage pipes, taps and appliances such as dishwashers and washing machines. Too low pressure results in poor operation and weak water flow.
If you cannot find the pressure reducing valve, if it looks damaged or if adjustment does not improve the water pressure, contact a plumber. In apartment buildings, the pressure reducing valve may be common to several apartments, in which case the condominium association or property owner must handle adjustments.
Safety aspects are important when adjusting water pressure. Never raise the pressure above the manufacturer's recommendations for your piping system. Old pipes cannot withstand as much pressure as modern systems, and too much pressure can cause leaks or burst pipes.
What to do if only one tap has low water pressure?
When only one specific tap has low water pressure, the problem is usually localized at that particular tap. Start by checking the faucet valves under the sink or basin. These small valves control the water supply and may have been turned off partially by accident, especially after repairs or cleaning.
Open the cabinet under the faucet and look for two small valves, one for cold and one for hot water. Turn them fully counterclockwise to ensure they are fully open. Test the water pressure again. If only the hot water is low, the problem is probably in the hot water valve or in the hot water system.
Clean the faucet aerator following the steps described earlier. This will solve most problems with low water pressure in individual taps. If the aerator is clean and the valves are open, there may be a blockage in the internal parts of the tap or in the supply hoses.
Check the supply hoses running from the valves to the tap. Turn off the water, disconnect the hoses and inspect them for lime or dirt. Sometimes small pieces of limescale or debris from the piping system can get stuck in the connections. Flush the hoses with water and reconnect them.
If the problem persists after these measures, the faucet itself may be defective. Older taps may have internal limescale deposits or worn parts that restrict the flow of water. In such cases, it is usually more practical to replace the tap than to try to repair it. Modern taps are energy efficient and provide better water pressure.
When do I need to contact a plumber for water pressure problems?
You should contact a plumber when the water pressure is low in several taps at the same time, when simple measures do not help or when the problem lies in the main water line or piping system. Professional help is also needed for defective pressure reducing valves and extensive limescale deposits that require flushing of the pipes.
Problems with the main water supply are indicated by low water pressure throughout the property. This may be due to a leak, blockage or failure of the municipal water main. A plumber can investigate the system, find the cause and coordinate any action with the municipality if the problem is outside the property.
Extensive limescale deposits in the piping system require professional flushing or replacement of pipes. If you have tried cleaning aerators and adjusting valves without success, and the water pressure has deteriorated gradually over a long period of time, limescale in the pipes is the likely cause. A plumber can assess the condition of the piping system and recommend appropriate action.
Defective pressure reducing valves need to be replaced by a professional. If the valve is leaking, cannot be adjusted or if the pressure varies greatly, this is a sign that it is defective. Replacing a pressure reducing valve requires knowledge of piping systems and the right tools to avoid water damage.
We offer 24-hour assistance for both emergency water pressure problems and planned measures. If you experience a sudden drop in water pressure, a leak associated with low pressure or if you are unsure how to deal with the problem, you can contact us at any time. Our plumbers are experienced in all types of water pressure problems and can quickly identify and fix the cause.
For less urgent problems such as gradual deterioration of water pressure, you can book a visit at a time convenient for you. We will help you improve the water pressure in your apartment or house and advise on long-term solutions to avoid future problems.
