Fixing a Leaking Sink Faucet

If you have plumbing, chances are good that some day, you’re going to encounter a leaking faucet in your Boston home. Faucets leak for a variety of reasons, but fixing them can be a relatively simple task. Faucets can leak due to faulty gaskets or o-rings, dirty or corroded valve seats, or threads that have not been properly sealed. You’ll need to replace a leaking faucet outright if part of the faucet housing is cracked or broken (as might be the case with a plastic fixture) but often, a simple repair will do the trick.

You’ll want to have a bucket and some old towels or rags on hand; flat and Phillip’s head screwdrivers; a pair of vice grips, or an adjustable wrench; a flashlight, steel wool and Teflon tape at the very least. You may need additional tools and supplies, depending upon the type of leak you find. If you have to replace the faucet assembly, you’ll also want to have some plumber’s putty on hand.

Turn off the water at the faucet by turning the fixture’s individual cutoff valves to the closed position. If your sink doesn’t have individual cutoff valves for the hot and cold water, you’ll need to turn the water off at another cutoff or the main shutoff for the house. Open the faucet handles to drain the remaining water.

When the faucet is drained, you’ll need to disconnect the faucet from the supply lines. Typically, these are threaded connections located under the sink. Over time, mineralization and corrosion may have built up at the connectors but a good twist with the adjustable wrench should loosen the threaded connections. Place the ends of the disconnected supply lines in the bucket to catch any additional water that may be present in the lines. If you’re working with a bathroom sink, you may also have to disconnect the sink stopper control before you can remove the faucet. The sink stopper control is often held into the faucet assembly with a clip that attaches to a lever. Simply disconnect the clip, and then remove the faucet fixture.

Check the neck and the body of the faucet fixture for obvious cracks, bends, breaks or other non-repairable failures. If you find a major problem like these, you’ll need to replace the entire faucet assembly.
Assuming you find nothing serious, you may have to disassemble the faucet handles to get a good look at moving parts of the faucet. Usually the faucet handles are held on with a hidden screw, or the handles themselves are threaded into the fixture. If you’re working with a hidden screw, you can usually pop the caps off with a screwdriver blade or other flat edge, then unscrew the faucet handle.

Check for deteriorated gaskets, corrosion or other build-up that will prevent the faucet from sealing properly. Carefully remove the old gasket(s) and clean the entire area where the gaskets are seated. Check also the gaskets that may remain seated in the supply lines. Inspect the threaded connections for debris, corrosion or other problems that might prevent a good seal. Remove old bits of rubber gasket, corrosion or mineral build-up with steel wool. Regular white vinegar will also dissolve mineralization.

You may need to take the old gasket to the store to find an exact replacement. Gaskets of all sizes are common and they’re easy to find at a home-improvement store. It’s important to use the correct gasket to ensure a good fit.

Once you have replaced the gaskets, you’ll need to wrap all threaded connections in Teflon tape. A good Teflon seal can help prevent leaks. Replace the faucet assembly and reattach the handles. Connect all threaded connectors and be sure to tighten them correctly. Don’t over-tighten threaded connectors because this can cause a poor fit and – you guessed it – leaks.

Turn the water supply to the faucet back on and check for leaks. If you can’t find the source of the leak or your repair attempts don’t work, you can call Boston Standard Plumbing at (617) 288-2911 and we can locate and eliminate the source of your faucet leaks.