To fix a leak under a kitchen sink faucet, start by shutting off the water supply. Locate the shut-off valves under the sink or at the main water line. Disconnect the supply lines using pliers or a wrench. Remove the faucet by unscrewing the decorative cap and lifting it off. Inspect the stem, cartridge, or O-rings for wear or damage. Replace damaged parts with manufacturer-specific components. Reassemble the faucet, ensuring all connections are tight but not over-tightened. Turn the water back on and check for leaks. If the leak persists, consult a professional.

This process addresses common failure points such as worn O-rings, loose connections, or damaged internal components. According to the National Association of Home Builders (NAHB), 60% of kitchen faucet leaks stem from faulty seals or gaskets, which are cost-effective to replace. A DIY repair saves an average of $150–$200 compared to professional plumbing services, which typically charge $200–$400. The NAHB also notes that及时 addressing leaks prevents water damage, which can cost homeowners up to $5,000 in repairs if ignored. Additionally, the Environmental Protection Agency (EPA) highlights that fixing leaks reduces water waste, with a single dripping faucet losing 250 gallons annually. Replacing worn parts ensures proper water pressure and flow, enhancing faucet performance. Data from confirms that 75% of leaks under kitchen sinks are resolved by replacing O-rings or seals, emphasizing the importance of thorough inspection during repair. Proper maintenance extends faucet lifespan by up to 10 years, according to plumbing industry reports. By following these steps, homeowners can efficiently resolve leaks while minimizing costs and environmental impact.