Cause 1: A Clogged Aerator
The small mesh screen at the very tip of a faucet — the aerator — catches mineral deposits and small debris from the water supply over time, particularly relevant given Arlington's moderately hard municipal water, which contains enough mineral content to gradually build up and restrict flow through this small screen even under otherwise completely normal household water pressure conditions.
Why This Is Worth Checking First
Unscrewing and cleaning (or, if significantly built up, simply replacing) the aerator solves a genuinely surprising number of single-fixture low-pressure cases in just a few minutes, making it far and away the most sensible, lowest-effort first step before assuming anything more involved or costly is actually wrong.
Cause 2: Cartridge or Valve Restriction
Mineral buildup can also accumulate directly inside the faucet's internal cartridge or valve mechanism itself, restricting flow even when the aerator at the very tip has already been thoroughly cleaned or entirely replaced — this requires actually opening the faucet body to access and clean or replace the internal cartridge component directly.
How This Differs From a Simple Aerator Clog
If cleaning or replacing the aerator alone doesn't resolve the reduced pressure, this internal cartridge-level buildup is the next most likely suspect, particularly relevant for an older faucet that hasn't had any internal maintenance or cartridge replacement performed in several years or more.
Cause 3: A Partially Closed Shutoff Valve
The angle stop valve located under the sink, feeding that specific fixture, may not be fully open — this can happen after any nearby plumbing work was performed (even work unrelated to that specific fixture), or occasionally simply from the valve being accidentally bumped or partially closed at some point without anyone specifically noticing at the time.
Why This Is Worth Checking Before Assuming a More Complex Cause
This is a genuinely simple, completely free check — locate the shutoff valve under the affected sink and confirm it's turned to the fully open position — that's absolutely worth ruling out before assuming a more involved, complex cause is actually responsible for the reduced pressure you're experiencing.
A Simple Diagnostic Sequence to Follow
Step 1: Check and Clean the Aerator
Unscrew it, inspect for visible mineral buildup or debris, clean thoroughly or replace if needed, then test the faucet again before moving on to the next step.
Step 2: Confirm the Shutoff Valve Is Fully Open
A quick, genuinely free check worth doing before assuming anything more complex or costly is actually the underlying cause.
Step 3: Consider Internal Cartridge Buildup
If the two simpler checks above don't resolve the reduced pressure, internal cartridge or valve restriction becomes the more likely remaining explanation, at which point professional service becomes genuinely worthwhile.
Could This Actually Be a Sign of a Hidden Leak?
Rarely, in the specific case of pressure reduced at just one single fixture — hidden leaks more commonly cause noticeable whole-house pressure changes rather than affecting just one isolated fixture in isolation, since a leak anywhere in the supply system generally affects the overall system pressure rather than selectively targeting one specific tap. If you're also noticing broader whole-house pressure changes alongside the single-fixture issue, that combination is worth mentioning directly to a plumber, since it may point toward a different, more systemic underlying cause than what's covered in this specific guide.
How Often Should Aerators Be Cleaned Preventively?
Every 6 to 12 months is a reasonable general interval in areas with moderately hard water like Arlington's municipal supply, helping maintain consistent flow and pressure over time rather than waiting for a noticeable reduction to prompt the cleaning — a small amount of routine, preventive maintenance that avoids the larger buildup that eventually causes a genuinely noticeable pressure drop.
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Frequently Asked Questions
How often should aerators be cleaned as routine maintenance?
Every 6-12 months is reasonable in areas with moderately hard water like Arlington's, helping maintain consistent flow before buildup becomes significant enough to notice.
Could reduced pressure at one faucet be a sign of a hidden leak elsewhere?
Rarely for a single, isolated fixture — hidden leaks more commonly cause whole-house pressure changes rather than affecting just one specific tap in isolation.
Can I clean a faucet aerator myself without any special tools?
Yes — most aerators unscrew by hand or with basic pliers, and cleaning involves simply removing visible mineral deposits or soaking the screen in a descaling solution.
Is it normal for pressure to be slightly different between different faucets in the same house?
Some minor variation can be normal based on fixture design and distance from the main line, but a significant, noticeable difference at one specific fixture usually points to one of the causes covered here.
Should I replace the whole faucet if cleaning the aerator doesn't help?
Not necessarily — internal cartridge cleaning or replacement often resolves the issue without needing full fixture replacement; this is worth attempting before assuming replacement is required.
How do I know if my shutoff valve is fully open or just appears open?
A quarter-turn ball valve should be fully in line with the pipe when open; a multi-turn gate valve should be turned counterclockwise until it stops moving freely — worth confirming directly rather than assuming based on appearance alone.