This component, typically located behind the washing machine and connected to the water supply lines, controls the flow of water to the appliance. It consists of a valve mechanism, often a ball valve or gate valve, and a handle or lever for manual operation. One valve controls the hot water supply, and another controls the cold. Closing these valves stops the water flow, allowing for repairs, maintenance, or preventing leaks when the appliance is not in use.
Preventing water damage is the primary function of these controls. By enabling users to isolate the water supply, they offer a crucial safeguard against leaks stemming from hose failures, appliance malfunctions, or other unforeseen issues. Historically, access to the main water supply was often the only way to stop water flow to an appliance. Dedicated supply line valves offer significantly improved convenience and safety, minimizing the risk of extensive water damage and costly repairs. They are now standard practice in modern plumbing installations for washing machines and other appliances.