How to Replace a Kitchen Sink Strainer

Signs of a Failing Strainer

The kitchen sink strainer is the chrome or stainless steel basket that sits in the drain opening. When the putty seal between the strainer body and the sink surface fails, water leaks into the cabinet below during dishwashing or whenever the sink is full. You may notice water stains, warped cabinet bottom, or a musty smell in the sink cabinet. A leaking strainer can also cause damage to the countertop and the floor beneath the cabinet if left unaddressed.

Removing the Old Strainer

From beneath the sink, disconnect the tailpiece from the strainer body by unscrewing the slip nut. Use a strainer wrench (or channel-lock pliers in the crossbars visible from above) to unscrew the locknut holding the strainer body to the sink. If the strainer spins from above when you turn the locknut, have a helper hold the strainer from above with pliers inserted into the crossbars while you turn the locknut from below. Remove the strainer, locknut, washer, and old putty. Clean the sink surface around the drain opening thoroughly.

Installing the New Strainer

Roll plumber's putty into a rope about 1/2 inch in diameter and press it around the underside of the new strainer flange. Press the strainer into the drain opening from above. From below, slide the rubber gasket onto the strainer body, followed by the cardboard friction ring (if included), and then thread the locknut. Tighten the locknut while holding the strainer from above to prevent rotation. Continue tightening until putty squeezes out evenly around the flange. Wipe away excess putty from the sink surface.

Reconnecting the Drain

Reconnect the tailpiece to the strainer body using the slip nut and washer. Ensure the P-trap connections are all secure. Turn on the water and fill the sink about halfway. Let the water drain and check underneath for any leaks at the strainer body, tailpiece connection, or P-trap joints. If the strainer connection leaks, tighten the locknut an additional quarter turn. If the tailpiece connection leaks, ensure the slip washer is properly seated and the slip nut is hand-tight plus a quarter turn.