Faucet makes noise — hammering, squealing, or chattering
Reported Symptom
Faucet makes noise during use: squealing or whistling when open, hammering/banging when shut off quickly, or chattering or vibrating sound during flow.
Safety Warnings
- •Squealing hot water faucets can indicate dangerously high hot water temperatures. Test hot water temperature with a thermometer if squealing is only on hot side — if above 130°F, reduce water heater temperature immediately.
Possible Causes
- 1Squealing: washer is wrong size, making seat contact at one edge
- 2Hammering: water hammer from fast-closing valve
- 3Chattering: loose washer or debris vibrating in seat
Tools Required
- Screwdriver
- Adjustable wrench
Parts Required
- Replacement seat washer (if chattering — match exact diameter)
Diagnostic Steps
For squealing faucet: sound from worn cartridge/washer contact. Replace the seat washer (compression faucet) or cartridge (single-handle). Squealing specific to hot water only = water heater temperature too high (above 130°F) causing steam pockets in lines.
Expected: Squealing stops after washer/cartridge replacement.
If fails: Still squealing after replacement = seat is damaged and needs resurfacing or replacement.
For chattering: usually a loose washer vibrating in the valve seat. Remove stem and check if washer screw is tight and washer is the correct size (sits flat against seat when compressed).
Expected: Washer screw tight; washer correct size.
If fails: Wrong size washer = replace with correct size. Washer that is too small chatters; too large causes squealing.
For hammering when shut off: install water hammer arrestors at the supply valves under the sink. Thread arrestors into the supply line before the supply lines or between shut-off valve and supply line.
Expected: Hammering eliminated after arrestor installation.
If fails: Hammering persists = static water pressure over 80 PSI. Check building pressure and PRV.
Solution
Most faucet noise is from washer wear (chattering/squealing) — a $1 repair. Water hammer at faucets is addressed with arrestors at the supply valves. Identify the noise type to target the correct fix.