How to find and turn off your main water valve
To stop a leak fast, turn the small valve right behind the leaking fixture clockwise until it stops. For bigger leaks you need the main valve, usually where the water line enters the home, near the meter, the water heater or a utility closet. In an apartment, ask the manager where your unit's shutoff is before you need it.
Picture a supply hose under the bathroom sink bursting at night.
Why it matters: Seconds matter in a leak, and nobody finds a valve calmly with water on the floor.
Steps
- Look under each sink and behind the toilet for the small shutoff valves on the supply lines.
- Turn one clockwise until snug, check the faucet no longer runs, then turn it back.
- Find the main valve: check near the water meter, the water heater, a utility or laundry closet, or where the pipe comes through the wall.
- In an apartment, ask the building manager in writing where your unit shutoff is and who can close the building valve.
- Tie a bright tag on the main valve and note its location on your safety and admin card.
- In a leak, close the nearest fixture valve first; if water keeps coming, close the main.
- After closing the main, open a low faucet to drain pressure. If the water heater is electric, switch off its breaker. If it runs on gas, leave it alone and ask the landlord or a plumber.
Stop and call a professional if
- a valve will not turn by hand, drips from its stem, or you cannot find the main
- water is near outlets, the electrical panel or light fixtures: stay out of the water and call the landlord or a plumber, and the utility if needed
Questions to ask the professional
- Where is my unit's shutoff, and who has access to the building valve?
- Is this valve due for replacement?
Common mistakes
- Searching for the valve for the first time while water spreads.
- Cranking a stiff old valve with a wrench until the stem snaps.
- Forgetting that the little valves behind fixtures can stop most leaks on their own.
Teach this to someone
A one page sheet for showing a friend, a teenager or a parent: what to say, what to show, and one question to check it landed.
Teach: How to find and turn off your main water valve
What to say
To stop a leak fast, turn the small valve right behind the leaking fixture clockwise until it stops. For bigger leaks you need the main valve, usually where the water line enters the home, near the meter, the water heater or a utility closet. In an apartment, ask the manager where your unit's shutoff is before you need it.
What to show
- Look under each sink and behind the toilet for the small shutoff valves on the supply lines.
- Turn one clockwise until snug, check the faucet no longer runs, then turn it back.
- Find the main valve: check near the water meter, the water heater, a utility or laundry closet, or where the pipe comes through the wall.
- In an apartment, ask the building manager in writing where your unit shutoff is and who can close the building valve.
- Tie a bright tag on the main valve and note its location on your safety and admin card.
- In a leak, close the nearest fixture valve first; if water keeps coming, close the main.
- After closing the main, open a low faucet to drain pressure. If the water heater is electric, switch off its breaker. If it runs on gas, leave it alone and ask the landlord or a plumber.
Where it stops
Stop and call a professional if a valve will not turn by hand, drips from its stem, or you cannot find the main.
Check question
A hose under the bathroom sink bursts. Which valve is fastest to close?
Answer: The small valve under that sink. The fixture valve right beside the leak stops it in seconds.
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Sources
This skill is general practice and draws on no single published source.
Written in our own words from the sources above. It is general information, not advice for your situation; where a professional, your doctor or your lease says something different, follow them.
Last reviewed . First published .