How to Close Your Main Water Valve and Fixture Stops
Why this matters
Closing a water valve sounds like nothing until water is running across the floor and the valve you are holding does not behave the way you expected. A lever that goes a quarter turn, a wheel that takes several turns, a small oval handle under a sink that has not moved in fifteen years: each one closes differently, and each one fails differently when it is old. Knowing which kind you have, which way it turns, and when to stop pushing is what turns a leak into a towel job instead of a broken valve on top of a broken pipe.
This card is about operating the valves. Where they are in your house is covered in Your Home's Shutoffs: Water, Gas and Electric; read that one first and tag yours.
Before you touch a valve: water and electricity
If water is near outlets, extension cords, the electrical panel, a water heater's controls or any plugged-in appliance, or is dripping from a ceiling light, do not walk into it or reach through it to get to a valve. Water carries electricity. If you can reach your electrical panel from a dry spot without standing in or touching water, you can shut off the breaker for that area or the main; see related How to Shut Off Power at Your Electrical Panel. If you cannot, stay out, and call an electrician, or 911 if anyone is in contact with the water or you see sparks or smell burning. A breaker you shut off for water stays off until the area is dry and an electrician has checked anything that got wet.
Stay out from under a ceiling that is sagging or bulging with water. It can come down without warning.
If the leak is at a gas appliance and you smell gas, that is not a water problem anymore: everyone out, no switches, call 911 or the gas utility from outside.
How the three valves you will meet actually close
GATE VALVE (wheel) BALL VALVE (lever)
OPEN CLOSED
.-----. wheel
'--+--' lever lever
| stem along across
=====|===== pipe =====O===== ===O===
[#] gate |
wedge |
CLOSE: clockwise, CLOSE: quarter turn, 90
several full turns, degrees, lever ends up
stop when snug across the pipe
FIXTURE STOP (under a sink, behind a toilet)
supply tube up to faucet or toilet tank
|
wall pipe ===[stop] oval or round handle
clockwise to close; most take a
few turns, some are quarter turn
sink: one hot, one cold toilet: one, low
Gate valve. Turning the wheel clockwise screws a metal wedge, the gate, down across the pipe. It takes several full turns, and the wheel gets snug when the gate seats. On an old gate valve the stem can break or the gate can come loose from it, and then the wheel turns but nothing moves inside. Old gate valves also often do not seal completely, so a trickle can keep coming.
Ball valve. Inside is a ball with a hole through it. Turning the lever a quarter turn rotates the hole across the pipe. Open is the lever lined up with the pipe; closed is the lever across it. It is the quickest and most reliable kind.
Fixture stop. A small valve where the supply line leaves the wall or floor. Many older ones are multi-turn, with a rubber washer inside that hardens over the years; newer ones are often quarter turn. Under a sink you will usually find two, hot and cold. Behind a toilet, one, low on the wall or floor.
Closing a fixture stop
Use this when the problem is at one fixture: a toilet that will not stop running or is overflowing, a leaking faucet, a supply line dripping under a sink.
Pick the right stop. For a toilet, the single stop below the tank. Under a sink, if you know which side is leaking, that one; if not, close both. Why: the stop closest to the problem shuts off only that fixture, so the rest of the house keeps water.
Turn it clockwise by hand until it stops. On a quarter-turn stop that is a short turn; on a multi-turn stop, keep going until it is snug. Why: snug is where the washer seats. What breaks if you skip it: a stop closed most of the way still lets water through, and the leak continues at a lower rate that looks like success.
Do not use pliers or a wrench on a stuck stop. If it will not turn with firm hand pressure, leave it and go to the main. Why: old stops are often brass or plastic with a thin stem, and a tool puts enough force on them to snap the stem or crack the body. What breaks if you skip it: a stop that breaks open under a sink becomes a full-pressure leak exactly where you were trying to stop one, and now only the main can close it.
Confirm it closed. For a toilet, flush it; the tank should not refill. For a sink, open that faucet; water should stop within a few seconds once the line empties. Why: a valve that feels closed is not always closed.
If the stop starts dripping at its stem after you move it, that is the packing (the seal around the stem) disturbed by the turn. A small drip into a bowl or towel is fine until the plumber arrives; a steady stream means close the main.
Closing the main water valve
Use this when there is no fixture stop for the problem (a pipe in a wall or ceiling, a water heater, a burst line), when a fixture stop will not close, or when you are not sure where the water is coming from.
Go to the main, and identify which kind it is. Lever or wheel. Why: the two close differently, and a person turning a lever valve the way they would a wheel can open it back up.
Lever: turn it a quarter turn until it crosses the pipe. It will stop on its own at 90 degrees. What breaks if you skip it: half a turn is not a thing on a ball valve; if you stop at 45 degrees it is still partly open.
Wheel: turn it clockwise, steadily, until it is snug. Count the turns; write the number on the tag afterward, because it tells the next person what normal is. Do not lean on it or use a tool to force the last part. Why: snug means the gate has seated. Forcing it past snug, or forcing a wheel that will not start moving, is how an old valve's stem breaks. What breaks if you skip the stop: a broken gate valve can be stuck closed or stuck open, and a plumber then has to replace it with the water shut off at the street.
If the wheel will not move with firm hand pressure, or turns freely without ever getting snug, stop. It is seized or broken inside. Call your water utility's emergency number and ask them to close the curb valve, the utility's shutoff near the street, and call a plumber. Why: the curb valve is the utility's to operate in most places, and it is the next way to stop the water.
Open a faucet low in the house to relieve the pressure and confirm the main closed. A laundry sink or a basement or first-floor faucet works; an outdoor faucet works if it is lower. Leave it open. Water should run strongly at first and then slow and fade within a minute or so as the pipes drain down to it. Why: this drops the pressure in the house's pipes, which slows a leak that is still dripping out of lines that are full, and it is your proof the valve sealed. What it means if it keeps flowing steadily: the main is not fully closed or does not seal, which is common on an old gate valve; go back to step 4.
Leave the water heater alone. Do not open its drain or change its settings. Its tank stays full when the main is closed. If the plumber needs it shut off or drained for the repair, they will do it.
Tag it. A note on the valve, "CLOSED for leak, date, time," keeps someone else in the house from opening it while you are on the phone.
Turning the water back on
Only after the leak is repaired, or the fixture it came from has its own stop closed.
- Close the faucet you opened, except leave one open on the top floor so air in the pipes has somewhere to go.
- Open the main slowly, a little at a time, not all at once. On a lever, ease it toward open over several seconds; on a wheel, a turn at a time. Why: water slamming back into empty pipes causes a hammering bang and can stress a fresh repair.
- Watch the repaired area and any wet ceilings for 10 minutes with the water on. A new drip means close the main again and call the plumber back.
- Run each faucet until the sputtering air clears, then close it.
- Open the wheel fully. Some plumbers suggest turning a gate valve back a quarter turn from fully open so it is less likely to stick there; either is fine.
Worked example: an overflowing toilet upstairs
The setup. An upstairs toilet's fill valve sticks open and the tank starts overflowing onto the bathroom floor. The water spreads across tile, nowhere near any outlet or light. The house has a multi-turn fixture stop behind the toilet and a wheel-style gate valve main in the basement, tagged from the owner's walk-through last year.
The fixture stop first. The owner reaches behind the toilet and turns the oval handle clockwise. It moves about half a turn and then will not budge. They stop there rather than going for pliers, because the stop is 20 years old and a snapped stem would turn a slow overflow into a full-pressure leak.
The main second. Down to the basement. The tag says "MAIN WATER, wheel, about 6 turns to close." The owner turns it clockwise: six turns and it is snug. They do not push past snug.
Confirming it. They open the laundry sink faucet in the basement. Water runs strongly, then fades to a trickle and stops in about 40 seconds. Upstairs, the tank has stopped overflowing. They leave the laundry faucet open and hang a "CLOSED" note on the main.
How much water. Say the overflow was running at about 2 gallons a minute, an illustrative figure. From first noticing it to the main being closed took about 4 minutes, about 30 seconds of it spent on the stuck stop. Four minutes at 2 gallons a minute is about 8 gallons: towels and a wet-vac, not a ceiling repair. Had the owner spent 10 more minutes working on the stuck stop, it would have been 14 minutes, about 28 gallons, much of it through the floor.
After. The plumber came the next morning, replaced the fill valve and the seized stop with a quarter-turn one, and the owner turned the main back on slowly with a top-floor faucet open, watching the bathroom ceiling below for 10 minutes. No drips.
What would have changed the order. If the water had been running toward a hallway outlet or into the ceiling over a light fixture below, the first move would have been the breaker for that area from a dry spot, before either valve. If the main's wheel had turned freely past six turns without getting snug, the next call would have been the water utility, to close the curb valve, rather than more force on the wheel.
References
- See related: Your Home's Shutoffs: Water, Gas and Electric
- See related: How to Handle the First Ten Minutes of a Water Leak
- See related: How to Shut Off Power at Your Electrical Panel
- Your water utility's emergency line and its guidance on the curb valve
- See related: When to Stop and Call a Licensed Pro Around the House