A leaky kitchen sink is one of the most common household problems and can waste gallons of water each day if ignored. Even a small drip can lead to higher water bills, moisture damage, or mold under your sink. Fortunately, most leaks are easy to identify and repair with just a few basic tools and careful attention.
Preparation
Before starting, turn off the water supply to your sink. Look for two small shut-off valves beneath the cabinet—one for hot water and one for cold. Turn both clockwise until tight, and place a bucket or towel underneath to catch any remaining water in the pipes.
Next, identify where the leak is coming from. Common sources include:
• The faucet base or handle, often caused by worn O-rings or gaskets.
• The water supply connections, which may have loose fittings.
• The drain or P-trap under the sink, where seals can dry out or crack.
Once you’ve located the problem, gather your materials: an adjustable wrench, screwdriver, replacement washers or O-rings, plumber’s tape, and a flashlight.
Steps
1. Fixing faucet leaks
If water is dripping from the faucet spout or pooling at the base, the issue is usually inside the handle assembly. Remove the decorative cap, then unscrew the handle and cartridge. Inspect the rubber O-ring or washer—if it’s cracked or flattened, replace it with a matching size. Lightly coat the new part with plumber’s grease before reinstalling.
2. Repairing leaks under the sink
If the leak comes from a connection under the sink, tighten each fitting using an adjustable wrench. Be careful not to over-tighten, which can damage threads or crush washers. For flexible water lines, apply a few wraps of plumber’s tape to the threaded ends before reconnecting them.
3. Fixing drain leaks
Leaks in the drain assembly or P-trap often come from worn-out washers or misaligned joints. Loosen the slip nuts, remove the old washers, and replace them. Reconnect the pipe, tighten the nuts by hand, and give a gentle turn with pliers to secure them.
After completing the repair, slowly turn the water back on and test for drips. Wipe the pipes dry, then check again after several minutes to confirm the leak is fully sealed.
Maintenance and Safety
Inspect under your sink every few months to catch early signs of leaks, especially around joints or supply hoses. Avoid storing heavy items that could shift and bump pipes. Replace rubber washers and hoses every few years, even if they appear fine, to prevent unexpected failures.
If a leak persists or involves corrosion in the pipes, it may be best to contact a licensed plumber. Quick action saves water, prevents damage, and keeps your kitchen running smoothly.
Fixing a leaky kitchen sink is a simple home maintenance task that pays off immediately. With patience and the right tools, you can prevent water waste and protect your cabinets from costly moisture damage.