Strainer & Drain Connection Leaks in the Kitchen Sink

The kitchen sink strainer is the metal component inside the sink's drain hole. The bottom of the strainer, visible underneath the sink, has a threaded end onto which the drain tailpiece connects, leading down to the other pipes that comprise the sink's plumbing. Avoid repair costs brought on by water damage and troubleshoot the cause of any leaks involving the strainer or pipe connections.

The Strainer Seal

During installation, the strainer is sealed to the kitchen sink with plumber's putty placed around the lip of the sink's drain. If the putty is not in place, water will continuously leak out underneath the sink, escaping through the unsealed area between the strainer and the sink's drain hole. To remedy this, disconnect the tailpiece, remove the locknut that holds the strainer in place from below and lift the strainer up out of the sink drain. Wipe away the debris from the drain hole and press plumber's putty into place around the drain opening. Reinstall the strainer.

Removing the Strainer Locknut

Removing the locknut on the strainer to complete the repair is sometimes the trickiest part. Use different tools, depending on the type of strainer design you have in place. Some strainers are designed with a clamp cup underneath, and a wrench normally works to remove the locknut on the bottom of the clamp cup. If the strainer uses a larger locknut and no clamp cup, it may be harder to remove. Place the edge of a metal chisel against the tabs on the locknut, then tap the chisel with a hammer to loosen it for removal.

Replacing the Strainer

If the sink strainer repeatedly fails to hold water in it, replace the strainer basket as an initial attempt at repairing the leak. The basket is the portion of the strainer assembly that plugs the sink drain. If the strainer continues to leak, replace the entire strainer assembly, which includes the strainer and basket, along with a rubber gasket -- and sometimes a metal gasket -- and the locknut.

Tightening Drain Connections

Whether the sink drainpipes are metal or plastic, they often use slip nuts to provide a watertight connection between them. Try tightening the slip nut at the connection that leaks and see if the leaking continues. If it does, loosen the slip nut and check that a washer is installed on the connection. If no, install a washer and tighten the slip nut. With metal pipes, use an adjustable wrench or pipe wrench to loosen and tighten the slip nuts. You can often tighten plastic pipes by hand. If necessary, finish tightening the plastic nut with a pipe wrench or adjustable wrench.

References

• Encyclopedia of Home Maintenance & Repair; William Spence