There are few things more frustrating than a faucet that delivers water in a limp trickle. Low water pressure wastes time, makes rinsing dishes take twice as long, and can signal a more serious underlying issue with your plumbing system.
The challenge is that low pressure has many possible causes — and the right fix depends on a proper diagnosis. Here is a systematic approach that starts with the simplest checks and works toward the more complex.
Step 1: Determine Whether It Is One Faucet or All of Them
Check pressure at multiple fixtures throughout your home. If only one faucet has low pressure, the problem is localised to that fixture or its supply line. If all your taps are weak, the issue is upstream — either your main supply, your pressure regulator, or your pipes.
Single Faucet: Check the Aerator First
The aerator is the small screened attachment at the tip of your faucet spout. It mixes air into the water stream and is the single most common cause of localised low pressure. Mineral deposits, sediment, and debris accumulate inside it and progressively block flow.
Unscrew the aerator by hand (or with cloth-wrapped pliers), disassemble the screen and disc, and soak in white vinegar for 30–60 minutes. Use a small brush to remove deposits. Reassemble and reattach. This simple fix resolves low pressure in the majority of single-faucet cases.
Single Faucet: Check the Shut-Off Valves
Under the sink, there are individual hot and cold shutoff valves. These are sometimes accidentally left partially closed — particularly after a repair or when someone has been working under the sink. Ensure both valves are fully open (turned counter-clockwise as far as they will go).
Single Faucet: Inspect the Supply Lines
Flexible braided supply lines can kink, especially if the cabinet under the sink is cramped. A kinked line restricts flow dramatically. Inspect the lines visually, and feel along their length for any sharp bends. If the line is kinked and cannot be straightened without risk, replace it — they cost very little.
Whole-Home Low Pressure: Check Your Pressure Regulator
If all fixtures are weak, start with your pressure reducing valve (PRV), usually located where the main supply enters the home. PRVs have a typical lifespan of 7–12 years. A failing PRV can cause both high pressure (dangerous) and low pressure (frustrating). A plumber can test and replace it in under an hour.
Whole-Home: Inspect for Leaks
A leak somewhere in your supply pipes will reduce pressure throughout the system. Turn off all fixtures, then check your water meter. If it is still running, you have a leak. Common locations include under floors, inside walls, and at pipe joints in the basement or loft. A leak detection service can find hidden leaks without destructive investigation.
Whole-Home: Mineral Buildup in Pipes
In hard water areas, mineral deposits build up inside pipes over decades, progressively narrowing the internal diameter and reducing flow. This is particularly common with older galvanised steel pipes. The long-term solution is re-piping with copper or modern PEX. Short-term, a whole-house water softener slows further buildup.
Is It Your Water Supplier?
Sometimes the issue is outside your property entirely. Contact your water supplier and ask whether there are known pressure issues in your area. Many suppliers in the UK are legally required to deliver water at a minimum pressure of 1 bar at your boundary. If supply pressure is below this, they must investigate and rectify it.
