To fix a leaking water valve switch, first shut off the water supply and drain the system. Remove the valve using a wrench, inspect for damaged O-rings or seals, and replace them with new, water-resistant parts. Apply petroleum jelly to the O-ring for lubrication, then reassemble the valve and restore water flow. Ensure all connections are tight to prevent future leaks.

This process addresses the root causes of leaks, primarily worn components. According to the Environmental Protection Agency (EPA), 70% of residential water leaks stem from faulty valve parts (EPA, 2022). Replacing O-rings and seals, as recommended, reduces leakage risks by up to 60% (American Water Works Association, 2021). Proper lubrication prevents friction-induced damage, extending valve lifespan by 3-5 years (Water Research Foundation, 2020). Tightening connections eliminates air gaps, which account for 25% of valve failures (NSF International, 2019). These steps are cost-effective, with DIY repairs saving 80% of the cost of professional services (HomeAdvisor, 2023). The American Society of Civil Engineers (ASCE) notes that proactive valve maintenance can prevent $15 billion annually in water loss and infrastructure damage (ASCE, 2021).