Quick Answer:
A high-pitched screech from a kitchen sink during normal use is usually caused by air moving through a restricted path, a worn or loose faucet component, supply-valve vibration, or a problem with a connected appliance or vent. Run targeted diagnostics that check connected appliances, venting behavior, and fixture-specific components to narrow the cause. If you cannot isolate the source or you see leaks or electrical issues, stop and call a professional.
Why This Happens
There are a few common reasons a sink will make a high, whistling or screeching sound during normal use:
- Air in the line or a blocked vent causes air to be forced through a small opening — that rush of air makes a high sound.
- Worn or loose faucet parts (cartridge, ceramic discs, seals) can vibrate or allow water to whistle as it passes a narrow gap.
- Partially closed or faulty supply shutoff valves can vibrate at certain flow rates and make a shrill noise.
- Garbage disposal or dishwasher connections can transmit motor or flow noise into the plumbing.
- Changes in house water pressure, or a failing pressure regulator, can produce or amplify high-pitched noises.
Step-by-Step What to Do
1. Note when the noise happens
- Run water from hot and cold separately and together. Does the sound occur with hot, cold, or both?
- Does the noise happen only at full flow, only at low flow, only when the disposal runs, or when other appliances run?
- Record whether running the dishwasher or washing machine triggers the sound.
2. Isolate connected appliances
- Turn off the dishwasher and washing machine, then run the sink. If noise stops, run each appliance one at a time to see which causes it.
- Check the air gap, drain hose, and disposal connection for kinks or loose fittings that could cause vibration.
3. Check venting behavior
- Listen for gurgling or whistling from other fixtures when the sink is used — that suggests a vent or trap issue.
- Look for an air admittance valve (AAV) under the sink. A failing AAV can whistle when it opens or closes. Do not remove a roof vent yourself; if you suspect a blocked roof vent, call a pro.
- As a simple test, run water quickly in a nearby fixture (bathroom sink or tub). If the sink noise changes, venting or shared drain airflow is likely involved.
4. Inspect fixture-specific components
- Remove and clean the faucet aerator — mineral buildup can create a whistling flow. Run water with the aerator off to see if noise stops.
- If the aerator didn’t help, test the cartridge or valve assembly. Worn cartridges or loose retaining nuts often cause squeals. Replace the cartridge if it’s old or visibly damaged.
- Check supply shutoff valves under the sink. Fully open them; if noise changes, a failing valve may need replacement rather than forcing it further.
- Run the garbage disposal with the sink empty and listen. If the motor or mounting vibrates, tighten the mounting bolts and check the rubber splash guard for wear.
5. Check water pressure and regulator
- If you have a pressure gauge, check household pressure. High pressure or rapid pressure changes can cause noise. If pressure is above normal (typically over 80 psi), consult a plumber to inspect the pressure regulator.
- Note whether the noise appears only when multiple fixtures run — that can point to pressure imbalance or a pressure-regulating device.
6. Try simple fixes and retest
- Clean the aerator and any screens, replace the faucet cartridge if worn, and tighten loose fittings. Test after each change to see if the noise stops.
- Temporarily shut off the disposal and dishwasher power and operate the sink solely to help pinpoint the source.
- Keep notes on what changes the sound — they help a professional if you need to call one.
What Not to Do
- Do not force fittings or overtighten plumbing parts to “make them stop” — that can crack parts or create leaks.
- Avoid using caustic drain chemicals to fix noises. They won’t cure vent or faucet issues and can damage pipes and finishes.
- Do not ignore early warning signs like new noises, intermittent leaks, or burning smells from disposal motors; small problems can become bigger and more costly.
When to Call a Professional
- Call a plumber if the screech persists after the basic checks, especially if you see leaks, loose fittings you cannot reach, or suspect a blocked roof vent.
- Get professional help if the noise is tied to the garbage disposal motor (burning smell, smoke, or the motor won’t stop), or if the house water pressure seems abnormally high or fluctuates widely.
- If your sink also overflows when the washer runs, that’s a related problem: Kitchen Sink Overflows When Washing Machine Drains.
- If the sound is part of odd drainage patterns that appear only at night, check this related issue: Kitchen Sink Stops Draining Late at Night.
Safety Notes
- Turn off water at the shutoff valves before disassembling faucet parts. If you are unsure how, shut off the main water supply and call a pro.
- Disconnect power to the garbage disposal at the breaker before working on it. Never work on electrical components while the circuit is live.
- Do not climb on the roof to inspect vents yourself unless you are experienced and have proper safety equipment — hire a professional for roof vent checks.
- Wear gloves and eye protection when handling metal parts or debris. Avoid chemical cleaners that can harm skin or finishes.
Common Homeowner Questions
- Why does the noise only happen sometimes?
Intermittent noise usually means the problem appears at certain flows or when a particular appliance or valve operates. - Can I fix a whistling faucet myself?
Often yes: cleaning the aerator or replacing the cartridge fixes many cases, but stop and call a plumber if you hit resistance or see leaks. - Is a whistling vent dangerous?
Not usually dangerous by itself, but a blocked vent can cause slow drainage and sewer gas odors; have a plumber inspect it if you suspect a vent problem.