Maintenance procedure · Written to ASD-STE100 Issue 9 · Formatted to ANSI Z535

Cleaning a Tap Aerator

Kitchen and bathroom taps — aerators with a housing, with an integrated thread, and recessed
ApplicabilityKitchen and bathroom taps with an aerator in the end of the spout
Task timeat least 29 min to 52 min (33 of 34 steps estimated) editorial estimate, not a measurement
PersonnelOne
Revisionv1 · 2026-07-29
BEFORE YOU BEGIN

Before you begin. This procedure is general reference information, not professional advice. Equipment varies by manufacturer, model, and year. Always follow the documentation supplied with your equipment — where it differs from this page, follow the manufacturer. Verify that you have the tools, the working conditions, and the ability to do this task safely. If anything is unclear, if the equipment is damaged, or if the task exceeds your experience, stop and use a qualified professional. You are responsible for your own safety and for the outcome. This site accepts no liability for any loss, damage, or injury arising from the use of this information.

Specifications marked unverified could not be traced to a manufacturer source. Do not rely on them — obtain the value from your equipment documentation.

Summary

When one tap goes weak, or the stream splits and sprays off to one side, the cause is almost always the aerator: the small screened insert in the end of the spout. It fills with grit from the supply and with limescale from hard water, and it is the cheapest thing in the house to fix. This page removes it, cleans it, and puts it back, and it does the whole job with a cloth and a soft brush.

The part of this job that is genuinely hard is not the cleaning. It is knowing what you are holding. Aerator threads run male and female across at least seven metric sizes and five imperial ones, some taps hide the aerator inside the spout so that it only comes out with the maker's own key, and the manufacturer of the aerator and the manufacturer of the tap flatly contradict each other on whether vinegar is safe to soak one in. This page will not print a thread size for your tap and it will not pick a side on the vinegar question. It shows you how to read the answer off the part in your hand, and it names both manufacturers so you can go to yours.

Safety

NOTICE

KEEP THE PARTS IN THE ORDER THAT YOU REMOVE THEM.
An aerator with the parts in the wrong order does not give the correct flow.

Necessary equipment

ItemNote
Soft brushAn old toothbrush is sufficient.
ClothUse the cloth to protect the surface of the tap.
Small containerThe container must hold all the parts of the aerator.
Adjustable pliers optionalUse the pliers only if the aerator does not move by hand.
Service key for a recessed aerator optionalThe key must be the key for the aerator in your tap.
Flashlight optionalThe end of a spout is a dark space.
Descaler that your tap manufacturer approves materialThe manufacturers do not agree about this descaler. Read the documentation for your tap.
Clean water materialThe water must be clean.

Identify the aerator

Estimated 2 min

NOTEAn aerator has a housing, an integrated thread, or a recessed fit. The removal method is not the same for the three types.
  1. Open the tap. Look at the flow of water.
    <1m
  2. If the flow is weak, or the flow goes to one side, the aerator has dirt in it.
    • A weak flow at only one tap points to that tap.
    • A weak flow at all the taps does not point to an aerator.
    <1m
  3. Close the tap.
    <1m
  4. Look at the end of the spout with the flashlight.
    <1m
  5. If you see a ring with flat sides around the screen, the aerator has a housing.
    <1m
  6. If you see a smooth end with two small holes, your tap has a recessed aerator.
    • A recessed aerator is inside the spout.
    • A recessed aerator comes out only with the service key from the manufacturer.
    <1m

Remove the aerator

Estimated 5 min to 9 min

NOTEThe thread is male or female. The direction to turn is not the same for the two threads.
Direction to turn the aerator to loosen it
Unverified — do not rely on this value
CONSULT THE TAP MANUFACTURER DOCUMENTATION. THE DIRECTION IS NOT THE SAME FOR A MALE THREAD AND A FEMALE THREAD

No tier-1 source was found for this value. Take it from the documentation supplied with your equipment.

Service key type for a recessed aerator
Unverified — do not rely on this value
CONSULT THE TAP MANUFACTURER DOCUMENTATION

No tier-1 source was found for this value. Take it from the documentation supplied with your equipment.

NOTICE

PUT A CLOTH IN THE DRAIN OPENING BEFORE YOU REMOVE THE AERATOR.
A small part that falls into the drain is difficult to get.

  1. Put a cloth in the drain opening.
    <1m
  2. Make sure that no water falls from the spout.
    <1m
  3. Hold the spout with one hand.
    <1m
  4. Turn the aerator with your other hand until the aerator is loose.
    • A male thread and a female thread do not turn in the same direction.
    • If the aerator does not become loose, use the opposite direction.
    <1m
NOTICE

PUT A CLOTH BETWEEN THE PLIERS AND THE AERATOR.
The pliers can cause damage to the surface of the aerator.

  1. If the aerator does not move by hand, put a cloth around the aerator.
    <1m
  2. Hold the cloth with the pliers. Turn the aerator again.
    1m
NOTICE

USE ONLY THE SERVICE KEY FOR THE AERATOR IN YOUR TAP.
An incorrect key can cause damage to a plastic thread.

  1. If your tap has a recessed aerator, put the service key into the two holes.
    <1m
  2. Turn the service key until the aerator is loose.
    <1m
  3. Remove the aerator from the spout by hand.
    <1m
  4. Put the parts on the cloth in the order that you removed them.
    • A photograph of the parts in order is a good record.
    <1m

Clean the parts

Estimated 15 min to 35 min

Chemical compatibility of a descaler with your aerator
Unverified — do not rely on this value
CONSULT THE DOCUMENTATION FROM THE MANUFACTURER OF YOUR OWN TAP

No tier-1 source was found for this value. Take it from the documentation supplied with your equipment.

Two tier-1 manufacturers disagree, and this page publishes the disagreement instead of choosing. NEOPERL, which makes the aerator, states in 'Farewell to lime and dirt: tips and tricks for aerator care' that cleaners containing hydrochloric acid, acetic acid, formic acid or chlorine bleach are best avoided because they can damage the aerator and fittings, and recommends citric acid with a soft brush. Delta Faucet, which makes the tap, states in 'How can I remove mineral deposits from my aerator?' that you should remove the aerator, soak it in vinegar overnight, then flush with water. Vinegar is acetic acid, so the two documents give opposite advice about the same chemical on the same part. Neither is averaged and neither is dropped. Ask the manufacturer of your own tap, and if you cannot reach an answer, use the soft brush and clean water only.
  1. Separate the screen, the insert and the rubber washer.
    <1m
  2. Rinse each part with clean water.
    <1m
  3. Remove the grit from the screen with the soft brush.
    2m
WARNING

DO NOT MIX TWO DESCALERS.
DO NOT MIX A DESCALER WITH BLEACH. An acid and bleach together make a gas that injures your lungs.

NOTICE

USE ONLY A DESCALER THAT YOUR TAP MANUFACTURER APPROVES.
Some acids cause damage to an aerator and to the surface of a tap.

  1. If limescale stays on the parts, put the parts in the approved descaler.
    • Read the documentation for your tap before you select the descaler.
    • Use one descaler only.
    1m
  2. Let the parts stay in the descaler for the time that your documentation gives.
    10m
  3. Remove the parts from the descaler.
    <1m
  4. Rinse each part with clean water again.
    <1m
  5. Examine the rubber washer for damage.
    • A washer with a cut or a flat area causes a leak at the thread.
    <1m

Install the aerator

Estimated 4 min

  1. Assemble the screen, the insert and the washer in the correct order.
    1m
  2. Install the aerator on the spout by hand.
    <1m
  3. Tighten the aerator by hand only.
    • A hand-tight aerator is easy to remove at the next clean.
    <1m
  4. Open the tap. Look at the flow again.
    <1m
  5. If water comes out at the thread, close the tap. Install the aerator again.
    2m
  6. Remove the cloth from the drain opening.
    <1m

Get a new aerator

Estimated 2 min (partly estimated)

NOTETake the used aerator with you. The used part gives the thread and the size.
Aerator thread type and thread size for your tap
Unverified — do not rely on this value
READ THE THREAD FROM THE USED AERATOR, OR CONSULT THE TAP MANUFACTURER DOCUMENTATION

No tier-1 source was found for this value. Take it from the documentation supplied with your equipment.

  1. If the flow stays weak after the clean, get a new aerator.
    <1m
  2. Take the used aerator to the parts counter.
    • The used part shows the thread and the size.
    • A measurement from a web page does not show them.
  3. Give the make and the model of your tap to the counter.
    1m
  4. Install the new aerator by hand.
    1m

Terminology

This page uses one term for each item and holds it throughout, as ASD-STE100 requires. Equipment sellers and other guides use the names below for the same parts.

aerator
Also called: faucet aerator, tap aerator, faucet screen, tap filter, faucet filter, sink screen, the mesh bit on the end of the tap, flow restrictor, spout tip
recessed aerator
Also called: cache aerator, Cache aerator, hidden aerator, concealed aerator, vandal-proof aerator, tamper-proof aerator, internal aerator, flush-mount aerator
service key
Also called: aerator key, aerator wrench, aerator removal tool, cache key, faucet key, that little plastic tool that came with the tap
tap
Also called: faucet, mixer tap, spigot, water tap, bathroom faucet, kitchen faucet
spout
Also called: faucet neck, tap outlet, the bit the water comes out of
limescale
Also called: lime, scale, hard water buildup, calcium buildup, mineral deposits, chalky white stuff

When to use a professional

Stop if you cannot close the tap. Stop if water comes out of the tap when you close the handle. Speak to a plumber.

Stop if the spout moves or turns when you hold it. The tap is loose below the basin and the work is not on this page.

Do not do work on the pipes above the stop valve for the fixture. Do not remove the tap from the basin.

This page does not give a thread size for your tap. This page does not select a descaler for you. Two manufacturers disagree about the agent, and the page names both. Ask the manufacturer of your own tap for these two answers.

Common questions

Why is the water pressure low in just one faucet?

Because the restriction is in that tap and not in the supply. The aerator sits in the end of the spout and it is the finest filter in the whole run, so it is where grit and limescale arrive first. If every tap in the house went weak on the same day, the aerator is not the answer and this page will not help. One tap, and especially one tap that has gone from a straight stream to a splayed spray, is the aerator almost every time.

Which way do I unscrew a faucet aerator?

It depends on which part carries the thread, which is why "righty-tighty" is not a safe guide here. Moen's own support library says a male threaded aerator unthreads by turning clockwise and a female threaded one unthreads by turning counter-clockwise. We are not going to print one direction for your tap, because printing the wrong one is how people force a plastic thread and turn a five-minute job into a new tap. Turn it gently one way; if it tightens, go the other way.

What size aerator do I need?

There is no answer to that question that a web page can give you honestly. NEOPERL, which manufactures a large share of the world's aerators, lists housings in female M16x1, male M18x1, female M19x1, male M20x1, female M22x1, male M24x1 and male M28x1, plus imperial female 3/8 inch, female 3/4-27, male 13/16-27, female 55/64-27 and male 15/16-27. That is twelve sizes across two measuring systems, split between male and female threads, before you reach the recessed types that need the maker's own key. Take the old one to the counter and match it against the part. NEOPERL's own advice for buying a replacement is to note the type of thread, female or male, and the size.

Can I soak the aerator in vinegar to get the limescale off?

Two manufacturers with equal standing give opposite answers, so we publish both rather than pick one. Delta Faucet's support page says to remove the aerator, soak it in vinegar overnight, then flush it with water. NEOPERL, which makes the aerator itself rather than the tap, says cleaners containing acetic acid are best avoided because they can damage the aerator and the fittings, and recommends citric acid with a soft brush instead. Vinegar is acetic acid, so this is a real disagreement about the same chemical on the same part, not a difference in wording. Ask whoever made your tap. If you cannot get an answer, the soft brush and clean water do most of the work anyway, and they cannot damage anything.

There is no screen on the end of my tap. Where is the aerator?

It is inside the spout. Recessed aerators, which NEOPERL sells as Cache and Moen calls concealed, are fitted flush so that nothing shows except a smooth ring with two small holes in it. They are deliberately hard to remove: the point of the design is that a passer-by cannot take one out. You need the service key made for that aerator, and NEOPERL notes that its keys come in different colours precisely because they are not interchangeable. If your tap came with a small plastic tool in the box, that is the key.

Is it worth cleaning the aerator, or should I just replace it?

Clean it first, because the part costs almost nothing and the cleaning costs nothing at all. If the flow is still weak after a proper clean, replace it. EPA's WaterSense programme points out that fitting a labelled aerator can save a family around 700 gallons a year, and that doing it can be as simple as twisting a new one on for a few dollars, so a replacement is not a defeat. Just take the old one with you when you buy.

Sources

Every specification on this page is traced to one of these sources. Tier 1 is a manufacturer document, a published standard, or a government safety authority. See Standards for the full tiering rule.

  1. Tier 1Bathroom FaucetsWaterSense, United States Environmental Protection Agency · accessed 2026-07-29 · re-verification due 2027-01-25
  2. Tier 1Aerators with housingNEOPERL GmbH · accessed 2026-07-29 · re-verification due 2027-01-25
  3. Tier 1Farewell to lime and dirt: tips and tricks for aerator careNEOPERL GmbH · accessed 2026-07-29 · re-verification due 2027-01-25
  4. Tier 1Replacing a faucet aeratorNEOPERL GmbH · accessed 2026-07-29 · re-verification due 2027-01-25
  5. Tier 1Faucet Aerator CleaningMoen Incorporated (Moen Solutions support library) · accessed 2026-07-29 · re-verification due 2027-01-25
  6. Tier 1How can I remove mineral deposits from my aerator?Delta Faucet Company (Masco Corporation) · accessed 2026-07-29 · re-verification due 2027-01-25
  7. Tier 1How to Safely Clean and Sanitize with BleachCenters for Disease Control and Prevention · accessed 2026-07-29 · re-verification due 2027-01-25

Revision history

Current version 1 · updated 2026-07-29 · next review due 2027-07-29

  1. v1 · 2026-07-29First draft. Thread sizes and the recessed-aerator key requirement from NEOPERL's own OEM product documentation; the male and female turn directions from Moen's support library; the acetic-acid disagreement from NEOPERL against Delta Faucet, published as a conflict rather than reconciled. No thread size and no cleaning agent publishes as a verified value. Written independently in Simplified Technical English; no source sentence was paraphrased.

Corrections to this page are listed in the public corrections log. Reports that are credible and not yet verified are listed in the public errata register, and an open one renders above the step it concerns.

Comments and corrections

Found an error? A correction with a manufacturer source is applied and logged publicly. You can also write to corrections@fixchecklist.com.

Every step above carries its own report control, which tags the report with that step so a correction reaches the right place. For anything about the procedure as a whole — the order of the sections, a step that is missing, something that did not match your equipment — use this: report something about this whole procedure.

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