# Low water pressure at home: how to find the cause and fix it yourself > Why water barely trickles from the tap: a clogged aerator or filter, a half-closed valve, pump settings or a narrow pipe. How to find the cause step by step and restore normal pressure. Web page: https://watertrade.com.ua/en/articles/article/slabyj-napor-vody · Other languages: [UA](https://watertrade.com.ua/articles/article/slabyj-napor-vody.md), [RU](https://watertrade.com.ua/ru/articles/article/slabyj-napor-vody.md) *November 8, 2026* ![Diagram: half-open ball valve, pressure gauge reading low, clogged filter cartridge and a debris-filled aerator on a mixer with a weak stream](https://watertrade.com.ua/uploads/articles/weak-pressure.jpg) Low pressure can almost always be fixed without replacing pipes. The key is not to guess but to narrow it down: one tap or the whole house, hot water only or both, all the time or at certain hours. Answering these three questions rules out half the causes straight away. ## What the diagram shows 1 — a mixer aerator clogged with sand, 2 — a dirty filter cartridge, 3 — a pressure gauge showing the system pressure, 4 — a valve that is not fully open. ## Step 1. One tap or the whole house If only one tap runs weakly, the problem is in that tap: - **The aerator.** Unscrew the small mesh at the spout by hand, or with a spanner over a cloth. Shake out the sand and rust, and dissolve deposits in vinegar or citric acid. - **The cartridge or valve head.** Debris also gets stuck in the inlet holes of a mixer cartridge. Shut off the water, remove the cartridge and rinse it. - **The flexible hose.** An old hose swells inside and narrows. Replace the whole hose. ## Step 2. Weak everywhere — check the pressure Look at the gauge after the pump or at the inlet. 2–4 bar is normal for a house. If the pressure is normal but the taps run weakly, water is losing pressure on the way. If it is low, the problem is the source. ## Step 3. Normal pressure, but no flow 1. **Filters.** The most common cause. A clogged cartridge or mesh can cut the outlet pressure almost to zero. Rinse the mesh and replace the cartridges — see [“How to replace a filter cartridge”](https://watertrade.com.ua/en/articles/article/zamena-kartridzha-filtra). 2. **Valves on the pipe.** After repairs someone may have left a ball valve partly closed. The handle should be in line with the pipe. 3. **Narrow pipes.** A long run of 16 mm pipe feeding several outlets will not give good flow however high the pressure. How to size pipes is explained in [“Choosing the pipe diameter”](https://watertrade.com.ua/en/articles/article/diametr-truby-vodoprovoda). 4. **Old steel pipes** rust up from the inside. Only replacing that section helps. ## Step 4. Low pressure — check the pump and tank - **Pressure switch settings.** If the pump cuts out at 2 bar, you will not get strong flow. How to raise the thresholds is explained in [“Setting up a pressure switch”](https://watertrade.com.ua/en/articles/article/nastrojka-rele-davleniya). - **Air in the pressure tank.** With the wrong air charge the flow surges between strong and weak. Check it using [“Checking the air charge”](https://watertrade.com.ua/en/articles/article/davlenie-vozduha-v-gidroakkumulyatore). - **The pump or the source itself.** A worn pump or a borehole that runs short of water also gives weak flow. If the pressure sags during long use and then recovers, the source cannot keep up with that demand. > Only the hot water is weak? Check the strainer at the water heater or geyser inlet and the heat exchanger itself: scale narrows the passage just like a dirty filter. > If the pressure in a flat drops at the same time for all your neighbours, the cause is the mains network. Call the water utility or the building manager — this is not a DIY repair. Replacement cartridges and meshes are in [filter cartridges](https://watertrade.com.ua/en/catalogue/filtry-dla-vody/kartridzi-dla-filtrov); pressure switches and gauges are in [pump controls](https://watertrade.com.ua/en/catalogue/nasosy/avtomatika-dla-nasosov). --- Watertrade · Phone: 067-421-96-27 · sale@watertrade.com.ua · Site map for language models: https://watertrade.com.ua/en/llms.txt