Low water pressure at home: your pipes, the building or the mains?
Catalunya Servei team ·
Before calling anyone, answer one question: is the pressure low at one tap, across the whole flat, or in the whole building? Each answer points somewhere different, and quite often the fix is simpler (and cheaper) than it looks.
The ten-minute test
Turn the kitchen cold tap fully on and fill a bucket or bottle of known size while counting the seconds. Do the same at the shower and the bathroom basin, then repeat with hot water. The exact figure doesn't matter: what helps is comparing points in your home against each other and, if you can, with a neighbour in the same building.
For a closer look, hardware shops sell pressure gauges that screw onto the washing machine tap. Read it with everything closed, then with a tap open. If static pressure is fine but drops sharply once water flows, something along the way is restricting it: scale, a half-closed valve or a dirty filter.
If only one tap is weak
This is the most common case and the easiest. Almost every tap has an aerator at the spout, a small mesh insert that mixes air into the water. With hard water it clogs with limescale within months.
- Unscrew it by hand, or with pliers wrapped in a cloth.
- Soak it for a few hours in vinegar or a descaler.
- Rinse and refit.
If water gushes with the aerator off but not with it on, you've found the culprit. If it's still weak, the problem is inside: the mixer cartridge, or the isolation valves under the sink, which are sometimes left half open after a repair.
Showers behave the same way with the shower head and hose. Water-saving heads have a flow restrictor, so if you changed yours recently and notice less water, that may be all it is.
If only the hot water is weak
- Gas water heater or combi boiler: scale builds up in the heat exchanger and inlet filter over the years. Hot water comes out weak and at an uneven temperature. That's a job for a heating technician.
- Electric water heater: check the safety valve and the inlet valve. An old tank full of sediment also loses flow.
- Thermostatic mixers: they have small inlet filters that block up.
If the whole home is affected
Check in this order:
- The main stopcock for the flat. Make sure it's fully open; old wheel-type valves that haven't moved in years can seize halfway.
- The pressure-reducing valve, if there is one. Many homes have one after the meter, and it can be badly set or faulty.
- An inlet filter nobody has ever cleaned.
- The pipes themselves. Older buildings still have runs of galvanised iron that close up inside with rust and scale until there's barely a passage left. Cleaning won't fix that.
Our plumbers see this regularly in flats in Barcelona's Eixample or Gràcia, or in the old quarters of Girona and Tarragona: a renovated kitchen and bathroom with brand-new pipes, connected to an old galvanised section nobody replaced. The renovated flat keeps the same poor pressure it always had.
If the whole building is affected
Ask a couple of neighbours, especially on the upper floors. If everyone notices it:
- The building's booster pump may have failed, or a rooftop tank isn't filling properly. The property manager (administrador de finques) handles that.
- Street works or a network incident. Check your water company's website or customer line.
Fitting a private booster pump in your flat to make up for a building problem is possible but rarely a great idea: it can worsen your neighbours' pressure, so talk to the residents' association first.
Indicative prices
| Fix | Typical range |
|---|---|
| Cleaning aerators and filters | DIY |
| Replacing a stopcock or pressure reducer | €80–200 including parts |
| Replacing a short section of exposed pipe | From €150–300 |
| Re-piping a whole flat | Depends on length and building work; usually done during a renovation |
These are market ranges to give you an idea; the actual quote depends on access and materials. We put ours in writing before starting.
When you don't need anyone
If a clean aerator solves it, if you find a half-closed valve, or if the whole building is affected by a water company incident, you don't need a plumber. Call us if pressure is still low throughout the home after these checks, if water comes out cloudy or brownish (a sign of iron pipes), or if you're planning a renovation and want to replace the pipework at the same time.
More information on our plumbing and full renovation pages.