Low water pressure in a flat: causes and fixes

Is the problem at one tap or throughout the flat

The first thing worth establishing is whether the weak flow is limited to one tap, one room, or the whole flat. Turn on the kitchen tap, then the bathroom sink, then the shower, one at a time, and compare. If only one fitting is affected, the cause is almost always local to that fitting or its immediate connection.

If every tap in the flat runs weak, including both hot and cold, the cause sits further back: in the internal pipework, a shared pressure reducer, or the building's supply. This distinction changes everything about what to do next, so it is worth five minutes with the taps before ringing anyone.

A clogged aerator is the most common cause

The little mesh screen at the end of a tap spout, the aerator, catches limescale, sand, and bits of rust from the pipework. In Tallinn's hard water this happens gradually over months, so the drop in pressure often feels sudden even though the cause was building up for a long time.

Unscrew the aerator by hand or with pliers wrapped in a cloth to avoid scratching it, and look inside. If it is coated in white scale or has visible grit, that is your answer. Soak it in vinegar for an hour, scrub with an old toothbrush, and rinse before refitting.

This is a job almost anyone can do with no tools beyond a pair of pliers, and it costs nothing but time. If the aerator is badly worn or the thread is stripped, a new one is a couple of euros at any hardware shop.

When the problem is in the mixer tap itself

If cleaning the aerator does not help, the restriction may be inside the tap: a clogged cartridge, a worn valve, or scale built up in the tap body itself. This is common in mixer taps over ten years old, especially in flats where the water has never been filtered.

Some cartridges can be removed and descaled the same way as an aerator, but on older or unfamiliar taps this is fiddly and easy to get wrong, particularly if you have never had the tap apart before. If the tap is old enough that parts are hard to find, replacing it outright is often the more sensible option.

We replace taps from 55 € per job, which usually works out cheaper than an hour of trial and error plus a part that may not even be the right one for that model.

When pressure is weak throughout the whole flat

If every tap and the shower all run weak, the cause is upstream of the individual fittings. In older Tallinn panel buildings from the 1960s to 1980s, the internal risers are often original steel pipework, and decades of limescale and rust can narrow the internal diameter significantly, restricting flow to an entire flat or even a whole stack of flats.

This kind of narrowing does not reverse itself and does not respond to cleaning a tap. Diagnosing whether it is the riser, the flat's internal branch pipes, or something upstream generally needs someone to actually look at the pipework and possibly test pressure at different points.

This is where it becomes worth calling a plumber rather than working through it alone. We charge from 45 € per hour for this kind of diagnostic work, with a minimum of one hour.

Pressure reducers and the building's technical systems

Many buildings, especially newer developments, have a pressure-reducing valve where the supply enters the flat or the building, set to protect the pipework from excessive mains pressure. If this valve is faulty or has drifted out of adjustment, it can quietly throttle the whole flat's supply.

In older buildings, the culprit is more often a shared pump or booster station serving the block, particularly on upper floors where mains pressure alone is not enough. A fault or a maintenance issue with this equipment affects everyone on the same riser at once, not just one flat.

If neighbours on the same stack report the same drop in pressure at the same time, that is a strong sign the cause is shared equipment rather than anything specific to your flat.

What is yours to fix and what belongs to the housing association

As a rough rule, anything from the point where the water enters your flat onwards is yours: your taps, your internal pipework, your shower. Anything before that point, shared risers, the building's pressure reducer, a communal pump, is the responsibility of the korteriühistu.

If you have checked your own taps and pipework and the fault clearly sits in shared infrastructure, the right step is to report it to the housing association's board or management company rather than pay for a fix that is not yours to pay for.

If you are not sure where the boundary falls in your specific building, a plumber can usually tell within a short visit whether the fault is inside your flat or upstream of it, which then tells you who should be dealing with it.

• Test each tap separately before assuming the fault is building-wide
• Clean or replace the aerator first — it is the cheapest and most common fix
• Suspect the tap itself if cleaning the aerator makes no difference
• Old steel risers in panel buildings narrow with limescale over decades
• A pressure reducer or shared pump can affect a whole stack of flats at once
• Ask neighbours on the same riser whether they have the same problem
• Report shared infrastructure faults to the housing association, not a private plumber