To fix a broken faucet valve core, first shut off the water supply under the sink or at the main valve. Remove the faucet handle by lifting it off or unscrewing it. Use pliers or a wrench to disconnect the supply lines. Next, disassemble the valve stem by unscrewing the cap and removing the stem. Extract the damaged valve core and replace it with a new one, ensuring it seats properly. Reassemble the stem, cap, and handle, then turn the water back on to test for leaks. If the seat is corroded, use a seat wrench to smooth it.

Valve core failures often occur due to mineral buildup, which occurs in hard water regions. The U.S. Geological Survey reports that 85% of U.S. households face hard water, leading to scaling and blockages. Replacing the valve core addresses this directly, as mineral deposits restrict water flow and cause pressure drops. A 2021 study by the American Water Works Association found that valve core replacements resolve 60-70% of persistent faucet leaks. DIY repair saves 80% of professional costs (average $150–$300 vs. $600–$1,000), according to HomeAdvisor. Additionally, proper installation prevents future failures by ensuring a tight seal, reducing water waste. The EPA estimates that fixing leaks saves homeowners 10,000 gallons of water annually. Regular maintenance, including annual valve inspections, further extends faucet lifespan by 5–10 years.