A whistling or screaming faucet can be a nagging problem for the handy homeowner. There can be many reasons for a whistling faucet, and diagnosing the problem means narrowing down possibilities, which basically entails examining your faucet and determining what has been replaced most recently and comparing against how long the faucet has been whistling.
Isolate the Problem
Isolate the source of the whistle as much as you can. Turn on just the cold water to see if the whistle is present. Repeat for the hot water. If the whistle is present only when one or the other is on, your problem is likely in that water line. If the whistle is only present after the hot water has been running for some time, the problem may be a washer issue, with an ill-fitting rubber washer further contracting in the hot water and causing the whistle.
To silence your chattering faucet, give the head a good cleaning. Mineral accumulation on the head or in the water lines can cause air to leak in and cause your whistling problem. Remove the faucet, and soak it in a cleaner indicated to remove lime and other mineral deposits. These types of solvents can be purchased at any home improvement store. Soak your faucet and all of its components in the solvent overnight, and give the water intake lines and spout a cleaning with a bottle brush.
If your washers are old or ill fitting, there may be air leaking back into the faucet as water comes out, causing your whistling problem. Replace your washers with the proper size for the faucet model you have. Rub your new washers down in petroleum jelly before installing them to ensure a good fitting and seal.
If you have attempted everything to alleviate the whistle, you may need to replace your faucet. Faucets, especially chrome-coated models, can hide substantial water damage, rust, and decay inside their shiny exteriors. Many a homeowner has been shocked to find the underside of their faucet rusted away and barely remaining connected to their sink while the chrome shell was as shiny as the day it was installed.