Why every household needs to know
A split pipe can release a remarkable amount of water in the time it takes a plumber to arrive. Every minute it runs, it soaks drywall, flooring, insulation and whatever is stored in the basement. Closing one valve stops all of it. The difference between a mopping job and an insurance claim is often just knowing where that valve is and whether it turns.
Tracking it down
- Head to the basement. Scarborough houses usually take their water in through the basement wall nearest the road.
- Find the meter. Look for a small dial or digital meter on the incoming pipe. Toronto's meters are usually near the floor, sometimes behind a panel in a finished basement or inside a closet under the stairs.
- Locate the valve. The main shut-off sits on the pipe just before the meter, on the street side. There may be a second valve just after the meter as well.
- Identify the type. A round wheel means a gate valve: several clockwise turns shut it. A straight lever means a ball valve: a quarter turn, until the lever crosses the pipe, closes it.
- Test it gently. Close it, check a second-floor tap goes dry, and then open it fully again.
- Label it. Hang a coloured tag there; it saves precious seconds for whoever is home when something happens.
Also find the valves for individual fixtures. Toilets, sinks, the dishwasher, the washing machine and the water heater each usually have their own. For a single leaking fixture, those are quicker and leave water running in the rest of the house.
Common slip-ups
- Forcing a stuck valve. Old gate valves can seize. Cranking hard with a wrench can snap the stem or break the valve body, causing the very leak you wanted to prevent.
- Only half-closing it. Gate valves need to be turned until they stop. If water still trickles from a tap afterwards, the valve may be worn inside.
- Hiding it. Basement finishing projects often box the valve in behind drywall. Insist on an access panel.
- Forgetting the hot water side. After the main is closed, also turn the water heater to pilot or vacation mode if the outage will be long, and check the instructions for your model.
If the valve fights back
If the valve will not turn, will not close fully, or leaks around the stem when you move it, it needs replacing. A modern quarter-turn ball valve is a simple swap and far more reliable in an emergency. Call too if you simply cannot find the valve: occasionally the service enters at an unusual spot, or the valve has been buried in a wall.
The City also has a curb stop, a valve near the property line under a small metal cap. It is for City crews and licensed plumbers only, so leave it alone. For more ways to keep a house safe through the winter, read our frozen pipes guide. If a drain is the problem rather than a pipe, our drain cleaning page explains what we do.