Replacing a kitchen faucet's valve core involves turning off the water supply, disassembling the faucet, removing the old valve stem and core using a wrench or pliers, inserting a new core with O-rings, and reassembling the components. Ensure the faucet is completely shut off and drain excess water. Use a quarter-circle wrench or adjustable pliers to loosen the stem, twist out the old core, clean debris, and install the new one with proper alignment. Test for leaks by turning the faucet on and checking under the sink.

This repair is critical because a failing valve core causes water waste, leaks, and reduced flow efficiency. According to the Environmental Protection Agency (EPA), a single dripping faucet can waste over 3,000 gallons of water annually, contributing to household water bills and environmental strain. A 2021 study by the American Water Works Association found that 35% of residential water leaks originate from faulty plumbing components like valve cores. Replacing the core early prevents costly water damage and plumbing repairs. Additionally, DIY valve core replacement saves 70-80% of the cost of professional service, which averages $150-$300 per repair. Regular maintenance extends faucet lifespan by 5-10 years, as outlined by the National Association of Home Builders. Neglecting this repair can lead to pipe corrosion, mold growth, and higher utility bills, making proactive replacement a cost-effective and eco-friendly solution.