Common Sink Valve Problems

Learn how water is distributed throughout your home and how to identify the types of problems that occur with sink valves.

Water enters your home from the main water line supplied by your city or county and into your home through a series of pipes. The supply pipes are split into hot and cold, with the hot supply going to the water heater where is it is heated then released throughout the house. Cold pipes run directly in. Pipes are galvanized or copper. Newer homes have copper, the preferred pipe of choice. Older homes have galvanized. Both types transport water throughout your home to a series of valves which can develop problems over time.

Valves are installed on every hot and cold water line. They control the flow by increasing or decreasing supply line flow to the faucet. The faucet is the final control, allowing you to adjust the flow mix of hot and cold water flowing out of the faucet.

Valves are subject to the same mineral corrosion which can clog pipes and erode the metal. Corrosion is the silent killer of plumbing, unnoticed until it becomes a problem. A corroded valve usually becomes stuck. The metal surface of the valve may become pitted or change color, depending upon the types of pipes you have and degree of "hard" or mineralized water supply.

Shrieking, humming, hissing, moaning or other irritating, unworldly sounds result for two reasons. One is if the valve contains a rubber gasket that has become brittle and unable to completely restrict water flow. When the faucet is turned on, water flows over the gasket, creating a noise like a reed in a musical instrument. The second cause is if you hear these sounds when you turn on any faucet, then the main supply line mixer valve is defective. If the noise is limited to one faucet, check the faucet gasket.

The most common problem is a leak. One cause is corrosion that erodes the metal valve parts which fails to make a proper seal and restrict the flow. Sometimes you may hear a hissing sound indicating a tiny pinhole. More often the leak begins at the valve shutoff control or at the supply line connection.

Supply line leaks become visible as water dribbling or streaming down the line at the point where the supply line connects to the valve. This is difficult to see if the leak is tiny. Evidence is general dampness in the cabinet, or a wet or warped cabinet floor. Left alone these leaks continue to increase and the moisture they create may form mold and mildew.

More unusual problems result when a supply line actually breaks, sometimes caused by accidental striking or pulling. Metal flexible tubing can corrode which may not be noticed until the line is moved or bumped, then a leak can spring into existence and flood the cabinet. Sometimes a rubber or plastic line can be inadvertently cut. Depending upon location, supply lines can also freeze and burst.

Settling of older homes sometimes creates leaks by applying pressure upon pipes and valves causing them to become misaligned.

Leaks don't go away by themselves. Once you spot one, act quickly to prevent further damage.

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