What is a shut-off valve?
A shut-off valve is a device that stops the flow of water to your entire home or to a single fixture, typically used during repairs or emergencies.
Every home has at least one shut-off valve, and knowing where it is can prevent serious water damage. A shut-off valve controls the water supply by cutting off flow when turned clockwise. There are two main types in Ontario homes: the main shut-off valve that controls water to the entire house, and fixture shut-off valves that control water to individual appliances like toilets, sinks, and washing machines.
The main shut-off valve is usually located near the water meter in a basement, crawl space, or utility room, though some homes have it outside near the street. It stops all water entering the property. Fixture shut-off valves sit beneath or behind specific appliances and allow you to cut water to just that item without affecting the rest of the house.
Two common valve types are gate valves (older, with a handle you turn many times) and ball valves (newer, with a lever that turns 90 degrees). Ball valves are generally more reliable and easier to operate.
Every homeowner should locate their main shut-off valve and test it annually to ensure it works. Knowing your valve location is critical during emergencies like burst pipes or leaking appliances, and essential before starting any plumbing repair work. If you cannot locate yours or suspect a valve is stuck, emergency plumbing services can help identify and resolve the issue.