A burst pipe or a leaking water heater can flood your home fast. When that happens, the most important thing you can do is stop the water flow, and that means knowing exactly where your outside water shut-off valve is located.
Many homes have their main shut-off valve outdoors: on an outside wall, near the water meter, or in a box by the street. This is especially common in Las Vegas and Reno, where many homes are built on concrete slabs instead of over a basement.
In this guide, we’ll show you where to find your outside water shut-off valve, how to turn it off safely, how outdoor faucet valves work, and how to protect your outdoor water lines in winter.
Key Takeaways
The outside water shut-off valve controls the water supply entering your house, so it’s the fastest way to stop a major leak.
It’s usually located on an outside wall facing the street, in the garage near the water heater, or in the water meter box near the curb.
Ball valves close with a quarter turn of the lever. Gate valves close by turning the round knob clockwise until it stops.
Outdoor faucets, also called hose bibs or sillcocks, have their own valves. Frost-free sillcocks help prevent freezing in colder climates.
Before winter, disconnect your garden hose, drain your outdoor faucets, and add insulated covers.
If a valve is stuck, leaking, or corroded, call a plumber instead of forcing it.
What Is an Outside Water Shut-Off Valve?
An outside water shut-off valve is an outdoor valve that controls the water supply entering your property. When you close it, water stops flowing to every faucet, toilet, and appliance in the house.
Some homes have only one main shut-off valve. Others have two: one indoors and one outdoors. A second valve outside gives you a useful backup; in one case, it matters when the indoor main valve is stuck or leaking and you still need to stop the water fast.
An outside valve also offers easier access in an emergency. You don’t have to walk through a flooded room or dig through a cluttered closet to reach it.
The valve is essential for plumbing repairs, too. A plumber needs to shut off the water before replacing pipes, fixing leaks, or installing a new water heater. Knowing where the valve is saves time on every service call.
Because outdoor valves are exposed to sun, heat, moisture, and temperature swings, durability matters. Brass valves hold up much better than plastic valves, which can crack from UV exposure over time.
Where to Find the Outside Water Shut-Off Valve
Every house is different, but outside shut-off valves are usually located in one of a few places. Start by figuring out where the main water line comes in from the street. The valve is typically along that path, near the property line or the foundation.
Once you find it, mark it with bright tape or a tag so everyone who lives in the home can find it quickly, and save this post for future reference.
On an Outside Wall of the House
In many homes, the main shut-off valve is on an outside wall, usually the wall facing the street. Look near the front hose bib, at the base of the wall, or where a pipe comes up out of the ground and enters the house.
Some valves sit behind a small access panel or inside a round or rectangular ground box close to the foundation. You may also see a pressure-reducing valve (PRV) nearby. It’s a bell-shaped fitting that controls your home’s water pressure. If your pressure seems too high or too low, see our guide on how to increase water pressure.
Clear away plants, gravel, and debris around the valve. An exterior shut-off valve must be accessible so you can operate it quickly in an emergency.
In the Garage Near the Water Heater or Softener Loop
In many Las Vegas homes, the main water line enters through the garage. Check the wall where a pipe comes up from the floor, often near the water heater or the loop of pipe that builders install for a water softener.
This valve isn’t technically outdoors. However, the garage isn’t living space, so many homeowners think of it as their outside valve. It controls the same water flow to the rest of the house.
In the Water Meter Box Near the Street
If you can’t find a valve on the house, check the water meter box. It’s usually a concrete or plastic box in the ground near the curb or sidewalk, with a lid labeled “water meter.”
Lift the lid carefully. Meter boxes in the desert can hide spiders, scorpions, and other pests, so wear gloves and look before you reach in.
You may see two valves in the box. The valve on the street side of the meter belongs to the water utility, and only utility crews should operate it. Tampering with it can damage the meter and may lead to fees. The valve on the house side of the meter, often called the customer valve, is the one you can use.
Many meter valves require a meter key or curb key, a long T-shaped tool that reaches down into the box. You can purchase one at most hardware stores, and it’s worth buying one before you need it.
If your home has a basement, check the front foundation wall there too. In homes with basements, the main valve is often within a few feet of where the water line enters.
How to Turn Off the Shut Off Valve and Stop Water Flow
Once you’ve found the valve, turning it off is usually easy. The method depends on the type of valve. Some valves use a lever, while others use a wheel-style handle, and each operates a little differently.
After you close any shutoff valve, open a faucet at the lowest point of the house, like a bathtub or an outdoor faucet. This drains the water left in the pipes and relieves pressure. If the running water slows to a stop, the valve is fully closed; if it does not, another issue may occur.
Ball Valves (Quarter-Turn Lever)
A ball valve has a straight lever. When the lever is parallel to the pipe, the valve is open. To close it, turn the lever a quarter turn so it’s perpendicular to the pipe.
Quarter-turn valves provide quick shut-off, which is why most plumbers prefer them for main shut-off valves. They’re also less likely to seize up than older gate valves.
Gate Valves (Round Knob or Wheel)
A gate valve has a round knob, sometimes called a wheel. Turn it clockwise (“righty-tighty”) until it stops. It may take several full turns.
Don’t force a stuck gate valve. Older gate valves can corrode, and too much force can break the stem or cause a new leak. If the knob won’t turn by hand, gentle pressure with a wrench is okay. If it still won’t move, call a plumber.
Shutting Off Water at the Water Meter
To use the customer valve in the meter box, fit your meter key or an adjustable wrench onto the valve. Turn it a quarter turn clockwise, until it’s perpendicular to the pipe.
Turn it slowly and gently. If you’re unsure which valve to turn, or the valve won’t move, stop and call your water utility or a plumber.
After any shutoff, turn off faucets that were open so they don’t overflow when the water comes back on. The Las Vegas Valley Water District offers more tips on preparing your home for water service shutoffs.
Outdoor Faucet Shutoff Valves and Outdoor Water Control
Not every outside valve controls the whole house. Outdoor faucets, also known as hose bibs or sillcocks, have their own valves. They control outdoor water flow to exterior fixtures like your garden hose, irrigation connections, and outdoor showers.
Most outdoor faucets use a simple knob or lever. Turning the knob clockwise closes the valve and stops the water at the tap.
In some homes, especially in colder climates, a separate shut-off valve controls the pipe connecting to the outdoor faucet. It’s usually indoors, in a basement ceiling, a utility room, or behind an access panel near the outside wall. Closing it lets you shut off outdoor water without turning off water to the rest of the house.
Like main valves, outdoor faucets must resist corrosion, UV exposure, and temperature changes. Worn washers are a common cause of a dripping outdoor faucet, and replacing them is often a quick fix.
Outdoor leaks can waste more water than most people realize. The EPA’s Fix a Leak Week guide recommends a simple test: check your water meter before and after a two-hour period with no water use. If the reading changes, you probably have a leak.
Frost-Free Sillcocks for Colder Climates
A frost-free sillcock is an outdoor faucet designed to prevent freezing. The valve that actually stops the water sits several inches back inside the heated part of the wall, at the end of a long stem. When you turn it off, the water left in the stem drains out, so there’s nothing left to freeze.
Frost-free sillcocks are a smart upgrade if you live in Reno or other areas with freezing winters. If your home doesn’t have a separate outdoor shut-off valve, installing frost-proof faucets is the next best protection.
One important note: a frost-free sillcock only works if the garden hose is disconnected. A connected hose traps water in the faucet, where it can freeze and burst the pipe inside the wall. You may not notice the damage until you turn the water on again in spring.
Anti-Siphon Backflow Protection
Some outdoor faucets include an anti-siphon valve, also called a vacuum breaker. It stops dirty water from a garden hose, sprayer, or pool from flowing back into your drinking water if the water pressure drops.
Many local plumbing codes require this protection on outdoor faucets. If your home has an irrigation system or other connections that need backflow protection, learn more about backflow testing.
How to Winterize Outdoor Water and Your Garden Hose
Winter can be hard on outdoor plumbing. When water freezes, it expands, which can crack faucets and burst pipes. Reno sees freezing temperatures every winter, and even Las Vegas gets freezing nights from time to time.
To protect your outdoor water lines before the first freeze:
Disconnect every garden hose from your outdoor faucets. Drain the hoses and store them in a garage or shed.
Close the outdoor faucet’s indoor shut-off valve, if you have one.
Open the outdoor faucets to drain the remaining water after shutting off the supply. If they’re on a separate shut-off line, leave them open for the rest of the winter.
Add insulated hose bib covers for extra protection against freezing, and place each cover securely over the faucet.
Insulate exposed pipes in unheated areas like garages and crawl spaces. Our guide to water pipe insulation explains how.
Shut off and drain your irrigation system.
Keep your thermostat at 55°F or higher, even when you’re away.
For more ideas, see our tips for winterizing the outside of your home.
It’s also a good idea to turn off your main outside water shut-off valve before a long trip. It reduces the risk of leaks while no one is home to notice them, and serious leaks are less likely to happen when precautions like this are taken.
Replacing a Stuck or Leaking Shutoff Valve
A shut-off valve you can’t turn is almost as bad as having no valve at all. Test your main valve twice a year by closing and reopening it. This keeps it from seizing and proves it works before an emergency.
Replace the valve if you notice:
A lever or knob that won’t turn, even with gentle pressure
Water dripping from the valve stem or body
Heavy rust or corrosion
A valve that doesn’t fully stop the water flow
Replacing a main shut-off valve usually means shutting off water at the meter, cutting the pipe, and installing a new valve. It’s one of the home repairs you shouldn’t tackle yourself unless you have plumbing experience. A licensed plumber can upgrade an old gate valve to a durable quarter-turn ball valve, usually in a single visit.
If the pipes near your valve are old or corroded, it may also be time to consider repiping. Professional water leak detection can find hidden leaks around valves and underground water lines.
Know Your Outside Water Shut-Off Valve Before You Need It
The best time to find your outside water shut-off valve is before an emergency happens. Take a few minutes today to walk around your home, find the valve, test it, and make sure everyone who lives there knows how to use it.
If your valve is stuck, leaking, or hard to find, Hawthorne Plumbing, Heating & Cooling can help. Our licensed plumbers locate, repair, and replace shut-off valves and outdoor faucets for homeowners in Las Vegas and Reno. Call our Las Vegas team at (702) 369-8777 or our Reno team at (775) 857-3333 to schedule plumbing services.
Frequently Asked Questions
It’s usually on an outside wall facing the street, near where the main water line enters the house, or in the water meter box near the curb. In many Las Vegas homes, the main valve is in the garage near the water heater or the water softener loop.
In most cases, you can operate the customer valve on the house side of the meter. Don’t touch the valve on the street side, which belongs to the water utility. If you’re unsure which valve is which, call your water utility first.
Many do. Some homes have a separate indoor valve that controls the line to the outdoor faucet, often in the basement, a utility room, or behind an access panel. Frost-free sillcocks also have a built-in valve that sits back in the heated part of the wall.
