Low Water Pressure in a Clogged Faucet Stop Valve

Lubricant

• The first attempt to unclog the stop valve can be done with an aerosol lubricant. Aerosol lubricants come with a long, thin straw to apply the lubricant in hard-to-reach places. On a single-handle faucet, turn the faucet on by pushing the handle back. Attach the thin straw and spray the lubricant around the handle at its joint. Move the handle around to distribute the lubricant. Reapply the lubricant and move the handle around again.

Hard Water

• Hard water causes buildup in and around the valve and can clog it. The buildup can be removed with cleaners made specifically for lime scale, but can tarnish the faucet's and sink’s metal. To avoid tarnishing the metal, use white vinegar in a spray bottle and generously spray the faucet. Allow the white vinegar to penetrate the buildup for about 20 minutes, then rinse it away.

Single Handle

• If simple solutions don’t unclog the faucet stop valve on a single-handle faucet, it should be replaced. Check with the faucet’s manufacturer to see if the faucet is under warranty before purchasing a new one. A replacement stop valve may be available from the manufacturer. Single-handle faucets come in a variety of styles with different mechanisms to operate the faucet, such as a ball, cartridge or ceramic disk. One of the parts in the faucet assembly may be broke or damaged, causing the clog.

Two Knobs

• A faucet with two knobs for hot and cold water uses compression to turn the water off and on. If simple solutions don’t unclog the stop valve, the non-working valve should be replaced. In two-knob faucets, small parts such as the seal and screws can break or wear out over time. The clog could be a result of a small, worn part stuck in the mechanism. The faucet's manufacturer will typically have a replacement knob available, as well as an assembly to repair the faulty knob.