How to Shut Off the Water to Your House (and Find the Valve Fast)

When a pipe bursts or a supply line lets go, every minute of running water adds to the damage. Knowing where your main shutoff is, and having turned it at least once before an emergency, is one of the most useful things a homeowner can learn. This guide covers where to look, how to close each common type of valve, and what to do when the valve will not cooperate.

Where the main shutoff usually is

The main valve sits where the water service line enters the building, so start by thinking about which side of the house faces the street or the water meter.

Home type	Where to look first
House with a basement	On the foundation wall facing the street, often near the floor, sometimes next to the meter
Slab foundation	In the garage, a utility closet, near the water heater, or on an outside wall close to a hose bib
Crawlspace home	Just inside the crawlspace access, near where the pipe comes through the foundation
Warm-climate homes	On an exterior wall, or in the meter box at the curb
Apartments and condos	Under the kitchen sink or near the water heater; some units share a building valve managed by the property

If you cannot find it inside, look for the water meter, which is usually in a covered box near the street or sidewalk. There is often a valve on the house side of the meter you are allowed to use, and a utility-side valve that may require a special key.

Identify the valve type and close it

• Gate valve (round wheel handle). Turn clockwise until it stops. It may take several full turns. Do not force it past the stop.
• Ball valve (straight lever handle). Turn the lever a quarter turn. When the lever is perpendicular (across) the pipe, the valve is closed; when it lines up with the pipe, it is open.
• Curb or meter valve. Usually a slotted stem or a valve with a tab. Use a meter key or wrench to turn it a quarter turn. In some areas only the utility may operate the valve on its side of the meter, so check with your water provider.

After closing the valve, open a faucet on the lowest floor and one on the top floor. The flow should slow to a stop as the pipes drain, which confirms the right valve is closed and relieves pressure in the lines.

Use the smaller valves when you can

You rarely need to shut off the whole house for a fixture repair:

• Toilets have a valve on the wall or floor behind the bowl.
• Sinks have two valves under the basin, one for hot and one for cold.
• Dishwashers usually share the hot valve under the kitchen sink.
• Washing machines have hot and cold valves behind the machine.
• Water heaters have a valve on the cold inlet pipe above the tank.
• Outdoor hose bibs often have an indoor valve feeding them, which is the valve to close before winter.

If the valve is stuck or leaks

Old gate valves that have not moved in years can seize, and forcing them can snap the stem or start a leak at the packing nut.

1. Try steady pressure with both hands rather than jerking the handle.
2. If it will not move, a small amount of penetrating oil on the stem and a few minutes of waiting can help.
3. A slight drip from the stem after turning often stops if you snug the packing nut a quarter turn.
4. If the valve still will not close in an emergency, use the meter or curb valve, or call your water utility’s emergency line.

A main valve that does not turn freely should be replaced with a quarter-turn ball valve. That is a job for a plumber, because the water may need to be shut off at the street.

Use your meter to check for hidden leaks

Once you know where the meter is, it doubles as a leak detector. The EPA suggests reading the meter before and after a two-hour period when no water is being used. If the reading changes at all, there is probably a leak somewhere, such as a running toilet or a dripping supply line. Closing individual fixture valves one at a time and rechecking the meter helps narrow it down.

Common mistakes

• Waiting for an emergency to look. Find the valve now, label it, and show everyone in the household.
• Forcing a gate valve. Turn firmly but do not use a long wrench as a lever.
• Forgetting to drain the lines. Opening a faucet after shutoff keeps water from spraying when you open a fitting.
• Turning gas valves by mistake. Gas valves are usually yellow-handled and on a gas line near appliances. Never use them as a water shutoff.

When to call a plumber

Call a plumber if the main valve is seized, leaks after you turn it, or you cannot find a shutoff anywhere inside the house. A plumber can install a modern quarter-turn ball valve, which makes the next emergency much easier. If a burst pipe is flooding the house and nothing will close, call your water utility’s emergency number to have the water shut off at the street.