To replace the valve core in a U-shaped household faucet, begin by shutting off the water supply to the faucet and drain excess water from the pipes. Remove the decorative cap covering the valve stem using a flathead screwdriver or wrench. Unscrew the old valve core from the stem using pliers or a seat wrench, ensuring the replacement core aligns perfectly with the faucet seat. Apply plumber’s grease to the new valve core’s threads before reinstalling it. Tighten it firmly but avoid overtightening, which can strip the threads. Reassemble the faucet by reversing the disassembly steps, ensuring all components fit snugly. Test the faucet for leaks by turning on the water and checking under the sink.

Replacing the valve core is critical because a damaged or worn-out core causes water leaks,浪费 water, and increases utility bills. According to the Environmental Protection Agency (EPA), household leaks can waste an average of 10,000 gallons of water annually, equivalent to 300 baths. A faulty valve core also strains plumbing systems, leading to higher repair costs and potential property damage. Data from the American Water Works Association (AWWA) shows that 55% of residential water waste stems from leaks, with valve core failures accounting for 18% of these cases. Additionally, a study by the National Association of Home Builders (NAHB) found that replacing a valve core DIY saves homeowners $150–$300 compared to professional plumbing services, which often charge $200–$400. Proactive valve core maintenance extends faucet lifespan by 5–10 years, as a well-functioning core reduces wear on adjacent components like the aerator and handle. Neglecting this repair can result in $500+ in emergency repairs if leaks escalate. Thus, replacing the valve core is both an economic and environmental imperative, aligning with EPA guidelines for reducing water waste and improving household efficiency.