To replace a faucet valve core, first shut off the water supply and drain excess water. Remove the faucet handle by lifting it off or unscrewing the decorative cap. Unscrew the old valve core from the base using a wrench or pliers. Clean the seat with a seat wrench or rag to remove debris. Insert a new valve core, ensuring it seats tightly, and tighten it clockwise. Reattach the handle and test for leaks. Always use a compatible valve core size to avoid compatibility issues.

Replacing a valve core addresses leaks and low water pressure, common in faucets over 5–10 years old. A 2021 study by the Environmental Protection Agency (EPA) found that leaks account for 10% of household water waste, with faulty valves contributing significantly. DIY valve core replacement saves homeowners an average of $150–$300 compared to professional plumbing services, according to HomeAdvisor. The process is cost-effective because valve cores cost $5–$20, while labor for a plumber averages $100–$200. Additionally, the American Water Works Association (AWWA) notes that 60% of faucet repairs involve valve core issues, as mineral buildup and corrosion degrade performance. Regular maintenance prevents water waste and extends faucet lifespan, aligning with EPA guidelines for reducing household water use by 10–20% through simple repairs.