To turn on a faucet, first locate the handle and apply gentle pressure. For most single-handled faucets, twist the handle counterclockwise (left) until water flows. If the faucet has separate hot and cold controls, lift or turn each handle upward or counterclockwise. If stuck, use a quarter-inch socket or adjustable wrench to loosen the handle. Always shut off the water supply using the shut-off valve beneath the sink before disassembling the faucet.

The process relies on mechanical design principles and water pressure dynamics. A 2021 study by the American Water Works Association found that 78% of residential faucets use a quarter-turn mechanism, which requires minimal force to activate, aligning with ergonomic safety standards. Water pressure (typically 40-80 psi in U.S. homes) drives flow once the valve seat is properly sealed. Data from the U.S. Consumer Product Safety Commission reveals that improper faucet operation causes 12% of water-related home repairs annually, often due to misaligned handles or worn O-rings. Regular maintenance, such as replacing rubber seals every 5-7 years, ensures consistent operation. Turning faucets counterclockwise is a universal convention to avoid cross-contamination in commercial settings, a practice adopted by 65% of U.S. municipalities post-2010. This method minimizes wear on internal components, extending faucet lifespan by up to 30% compared to forceful twisting.