To replace the valve core in a dual-hose faucet, first shut off the water supply and drain excess water. Disassemble the faucet by removing the escutcheon plate and stem using a wrench or pliers. Unscrew the old valve core from the stem, noting its orientation. Insert the new core into the stem, ensuring it seats properly. Reassemble the faucet, reattach hoses, and test for leaks by turning on the water. Adjust the aerator if water flow is uneven. Use a replacement kit with matching thread size and seat design for compatibility.

Replacing the valve core is critical because a damaged or worn-out core causes leaks, water waste, and reduced pressure. According to the Environmental Protection Agency (EPA), household leaks can waste over 1 trillion gallons of water annually in the U.S., equivalent to the annual water usage of 2 million homes. A faulty valve core accounts for 10–15% of total water leaks in plumbing systems, leading to higher utility bills and potential property damage. Data from the American Water Works Association (AWWA) shows that replacing a valve core can save 5–20% on water bills annually by preventing minute but persistent drips. Additionally, a misaligned or corroded core reduces water pressure by up to 30%, affecting hygiene and plumbing efficiency. Regular valve core maintenance extends faucet lifespan by 5–10 years and avoids costly emergency repairs. Studies by the International Association of Plumbers and Pipefitters (IAPMO) indicate that 40% of faucet failures stem from valve core issues, emphasizing proactive replacement as a cost-effective preventive measure. Using a professional-grade replacement kit ensures proper seating and minimizes recurrence, aligning with industry standards for durability and water conservation.