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How to shut off the main water supply

We'll find the main shutoff valve and turn it off so you can stop water flow during a leak or before plumbing work.

How-to · Home plumbing
2–5 min
What you'll need
  • Access to the basement, crawl space, or where the water line enters the house
  • Flashlight (for dark crawl spaces or meter boxes)
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Steps

Goal: Locate the main shutoff, turn it off, and confirm water has stopped.

  • Find where the water line enters the house—usually the basement, crawl space, or utility room.
  • Good: You see a valve on the main supply pipe. Proceed to Identify the valve type.
  • Bad: You cannot find it. See When to get help.

Locate the valve

Goal: Find the main shutoff before the pipe branches to fixtures.

  • Look in the basement, crawl space, or utility room where the water line enters. In apartments or condos, check the utility closet or ask the building manager. In warmer climates, check a box near the street or the garage. In cold climates, meter boxes can freeze—use a flashlight.
  • The valve is on the pipe before it splits to different fixtures. You should see either a wheel (gate valve) or a lever (ball valve).
  • Good: Valve found. Proceed to Identify the valve type.
  • Bad: Cannot find it. Call a plumber or your water utility.

Identify the valve type

Goal: Know which valve you have so you turn it the correct way.

  • A gate valve has a round wheel; turn it clockwise to close. A ball valve has a lever; when parallel to the pipe, water flows; when perpendicular, it is off.
  • Good: You know which type. Proceed to Relieve pressure.
  • Bad: Unclear—try turning the wheel or lever; gate valves turn, ball valves swing 90 degrees.

Relieve pressure

Goal: Reduce pressure so the valve is easier to close.

  • Open a faucet on the lowest level (e.g. basement sink) before turning off the valve. This relieves pressure and makes older gate valves easier to close.
  • Good: Water is running. Proceed to Turn off the valve.
  • Bad: No water from the faucet—the main may already be off. Proceed to Turn off the valve anyway.

Turn off the valve

Goal: Close the valve so no water flows into the house.

  • Gate valve: Turn the wheel clockwise until it stops. Do not overtighten.
  • Ball valve: Turn the lever 90 degrees so it is perpendicular to the pipe.
  • You should feel the valve seat when it is fully closed.
  • Good: Valve is off. Proceed to Test that water is off.
  • Bad: Valve will not turn. Do not force it. See When to get help.

Test that water is off

Goal: Confirm no water flows from any fixture.

  • Open a faucet on the lowest level (e.g. basement sink). Water should stop flowing within a few seconds.
  • If water still runs, you may have turned the wrong valve or there is a second shutoff closer to the meter.
  • Good: No water from the faucet. The main is off.
  • Bad: Water still flows. Check for another valve or call a plumber.

Leave the valve off until the repair is done

Goal: Keep water off until the leak is fixed or a plumber arrives.

  • Keep the main valve closed while you fix the leak or wait for a plumber. Do not turn it back on until the repair is complete.
  • Good: Valve stays off until you are ready. Proceed to Turn the valve back on when repairs are done.
  • Bad: Turned it back on too soon—turn it off again and finish the repair first.

Turn the valve back on when repairs are complete

Goal: Restore water flow without causing water hammer.

  • Gate valve: turn counterclockwise until fully open. Ball valve: turn the lever so it is parallel to the pipe.
  • Turn slowly to avoid water hammer. Open a faucet to release trapped air, then close it.
  • Good: Water flows normally from all fixtures.
  • Bad: Water hammer—banging or knocking in pipes. Turn the valve off, wait a minute, then turn on more slowly.

When to get help

Call a plumber if:

  • The valve is stuck, corroded, or will not turn. Do not force it—you can break the valve or pipe.
  • The valve leaks when you turn it (e.g. packing leak).
  • You cannot find the main shutoff.
  • You need to shut off water at the meter (usually requires a special key; the utility can do it).

Verification

  • The valve is fully closed (wheel turned clockwise for gate valve; lever perpendicular for ball valve).
  • No water flows from any faucet when you open one.
  • You know where the valve is for future emergencies.
  • You can turn it back on slowly when repairs are complete.

Have you found the main shutoff valve?

Usually in the basement, crawl space, or where the water line enters the house. In apartments, check the utility closet or ask the building manager.

Find where the water line enters the house—basement, crawl space, or utility room. In apartments or condos, check the utility closet or ask the building manager. Look for a valve (wheel or lever) on the main supply pipe. Good: you see the valve. Bad: cannot find—ask the building manager or call the water utility.

Yes No

You can change your answer later.

Locate the valve

The main shutoff is on the pipe before it branches to fixtures. In warmer climates it may be in a box near the street or in the garage. In cold climates, meter boxes can freeze—use a flashlight. If you cannot find it, a plumber or your water utility can help.

Done

Is it a gate valve (wheel) or ball valve (lever)?

Gate valve has a round wheel. Ball valve has a lever. The turn direction differs.

Identify the valve type. Gate valve: round wheel—turn clockwise to close. Ball valve: lever—when parallel to pipe, water flows; when perpendicular, it is off. Good: you know the type. Bad: unsure—do not force it; call a plumber.
Question

Is it a gate valve or ball valve?

Continue

You can change your answer later.

Did the valve turn off?

Open a faucet on the lowest level first to relieve pressure. Gate: turn wheel clockwise. Ball: turn lever 90 degrees perpendicular to pipe.

Open a faucet on the lowest level first to relieve pressure. Gate valve: turn the wheel clockwise until it stops. Ball valve: turn the lever 90 degrees so it is perpendicular to the pipe. Do not overtighten or force. Good: valve closed. Bad: valve stuck or will not turn—do not force; call a plumber.

Yes No (stuck)

You can change your answer later.

Test that water is off

Check that the faucet you opened has stopped flowing. Water should stop within a few seconds. If water still runs, you may have turned the wrong valve—check for another valve closer to the meter. When repairs are done, turn the valve back on slowly to avoid water hammer.

Done

Call a plumber

Do not force a stuck or corroded valve—you can break it and make the leak worse. Call a plumber or your water utility. In an emergency, the utility can shut off water at the meter (usually requires a special key).

Done

Reviewed by Blackbox Atlas

Frequently asked questions

Where is the main water shutoff valve?
Usually in the basement, crawl space, or utility room where the water line enters the house. In warmer climates it may be in a box near the street or in the garage. In apartments or condos, check the utility closet or ask the building manager; condos may have a unit shutoff and a building shutoff. In cold climates, meter boxes can freeze—use a flashlight and warm the box carefully if needed. Look for a valve on the pipe that runs from the meter or street into the house.
Which way do I turn the water valve to shut it off?
Gate valves: turn the wheel clockwise (right) until it stops. Ball valves: turn the lever 90 degrees so it is perpendicular to the pipe. When off, no water should flow from any faucet.
What if the main valve will not turn?
Do not force it. A stuck or corroded valve can break and make the leak worse. If the valve leaks when you turn it (e.g. packing leak), stop and call a plumber. Call a plumber or your water utility. In an emergency, you can shut off the water at the meter (usually requires a special key) or ask the utility to do it.

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