Overview
The main water shutoff is the single valve that stops all water to your house. In a plumbing emergency — a burst pipe, a major leak, a flooding water heater — this is the first thing you reach for. Every homeowner should know where it is and confirm it turns freely before an emergency happens.
How It Works
The main shutoff is located where the water line enters the house — usually in a basement, crawlspace, utility room, or near the water meter. Turning it fully clockwise (gate valve) or 90° (ball valve) stops all water flow into the house. Every fixture also has individual shutoff valves under the sink or behind the toilet for local repairs.
Key Components
Gate Valve (round wheel)
Older style. Turn clockwise to close. Can seize if not used for years.
Ball Valve (lever)
Newer style. Lever is parallel to pipe when open, perpendicular when closed. 90° turn.
Curb Stop
At the street, near the meter. Usually operated by the utility — not for homeowners.
Common Issues
Valve won't turn
Gate valves seize from mineral buildup if not exercised. Don't force it — it can break.
Valve leaks when operated
Worn packing or a corroded stem. Needs replacement.
Can't find the valve
Check where the water line enters — basement, crawlspace, or utility closet.
Maintenance Tips
- Find your main shutoff now — before you need it.
- Test it: turn it fully closed, run a faucet to confirm water stops, then reopen.
- If it's a gate valve and it's stiff, don't force it — call a plumber to replace it before it seizes completely.
- Label the valve so anyone in the house can find it in an emergency.
- Consider replacing a gate valve with a ball valve — they're more reliable.