How to Turn Off the Water to Your House

It’s not every day a homeowner needs to turn off the water to the house using the main water control valve. Some homeowners might not know its location, which can be a big problem if there is a leak, the water lines freeze, or a pipe bursts. Homeowners need to know how to locate and operate the main shut-off valve so they can quickly turn off the water in an emergency.

However, emergencies aren’t the only time a homeowner might need to turn off the water. When an old valve needs to be replaced, a faucet leaks, or a toilet needs to be removed, the water must be turned off to avoid flooding the immediate vicinity. Use this guide to learn where to find the main shut-off valve and how to turn off the water in your house.

Tips for Locating the Main Water Shut-Off Valve

The main water shut-off valve, also known as the building control valve, is typically located in one of several common areas. The home infrastructure can provide clues to the valve’s location. Use these tips to locate your home’s main water shut-off valve.

• Search common indoor and outdoor locations for the main building control valve, including the basement, crawlspace, mechanical room, exterior wall, or buried in the yard. If the home doesn’t have a basement or an accessible crawlspace, the main water line could come into the house where the water heater is located, although it might be under the kitchen sink.
• Check the street side of the property first. Contractors typically choose the shortest route from the water main to the house, so water supply lines generally run into the house from the street side of the property.
• Inspect the infrastructure to narrow down the possible location. Follow the cold water line back from the water heater to the main water line, or check for any branching water lines that you can trace back to where the main line enters the home.
• Look up the building inspection report to identify where the main water line and water shut-off are located. The building inspector should have tested the water shut-off during the inspection, so the location is typically noted in the report.
• Ask the previous homeowner. Although this is not always possible, it is a quick option to track down the water shut-off valve in the house, especially if you just purchased the property.
• Contact the local utility company. They may not know where the shut-off valve is for your home, but they can identify where the main line enters the building. They should also be able to indicate where the emergency curb stop valve is located outside the home in case you need to install a new main shut-off valve.

Types of Shut-Off Valves

In commercial, industrial, and institutional settings, various valves control the flow of water throughout the buildings. However, residential buildings typically only use two types of shut-off valves: gate valves and ball valves. Residential shut-off valves are generally ½-inch to 1 ½-inches in size and can be operated without tools.

• Gate valves have a circular handle connected to the body of the valve with a long stem. When the valve is turned counterclockwise, the valve opens to allow water to flow freely. By rotating it clockwise, the homeowner can close the valve to shut off the water to the home.
• Ball valves have a small ball inside the body of the valve. The ball has a hole through the center, so when the valve is open, the water flows through the hole. When the valve is closed, the ball rotates to block the flow of water. Ball valves are less likely to cause problems, so they are typically preferred over gate valves in modern construction.

How to Turn Off the Water Inside

Turning off the water to the home when the shut-off valve is located inside the house is usually straightforward. Start by locating the main shut-off valve on the main water line. The valve is often in the basement, close to where the main water line enters the home, although it may also be in a crawlspace or utility room. In the basement, the valve is typically positioned around eye level; in a main-floor utility area, it is installed closer to the floor.

After tracking down the valve, do a quick inspection to determine its condition. If the valve is significantly damaged, rusted, or worn, replace it immediately. However, if the valve seems like it’s in good shape, go ahead and test its functionality.

Gate Valve

Rotate the circular handle on a gate valve clockwise until it cannot turn any further to turn off the water to the house. The valve might be difficult to move if it hasn’t been used in a while. Use adjustable pliers or a pipe wrench to gently encourage the valve to rotate, but don’t apply so much pressure that you break the handle or the valve stem.

Ball Valve

With a ball valve, turn the lever 90 degrees so it sits perpendicular to the water line. This rotates the ball inside the body of the valve, blocking the flow of water and shutting off the water to the house. If the valve is difficult to move, use adjustable pliers to get a better grip, but work slowly and gently to avoid damaging it.

How to Turn Off the Water Outside

The water shut-off valve isn’t always located inside the home. In warm climates, it may be mounted on the exterior wall of the home or buried in the yard. Start searching the exterior of the house near the outdoor hose faucet.

If you can’t spot the valve after circling the home a couple of times, it may be in a utility box in the yard. These boxes are often made of green or black plastic. If you cannot locate the valve in the yard, there is a chance that the house doesn’t have a main shut-off valve, so you need to use the emergency curb stop valve to turn off the water to the house. You must be authorized by the local water utility to use this valve. Otherwise, you need to contact the utility directly to have them operate the valve.

After you locate the main shut-off valve or the curb stop valve, inspect the condition of the plumbing before proceeding. If the valve is in poor shape, have a professional plumber replace it instead of relying on rusted, worn, or potentially leaking fixtures. If the plumbing looks to be in good condition, proceed with operating the valve.

Gate Valve

Rotate the circular handle on a gate valve clockwise until the valve cannot turn any further to turn off the water to your house. The valve might be difficult to move if it hasn’t been used in a while. Use adjustable pliers or a pipe wrench to gently encourage the valve to rotate, but don’t apply so much pressure that you break the handle or the valve stem.

Ball Valve

For a ball valve, turn the lever 90 degrees so it sits perpendicular to the water line. This rotates the ball inside the body of the valve, blocking the flow of water and shutting off the water to the house. If the valve is difficult to move, use adjustable pliers to get a better grip, but work slowly and gently to avoid damaging it.

Emergency Curb Stop Valve

This valve is located deep in the ground and can only be operated with a specific tool known as a curb key. If you have a curb key and are authorized to use the curb stop valve, lower the curb key into the curb stop shaft until it hits the valve at the bottom. Rotate the key until you feel it settle down onto the pin at the bottom of the curb stop shaft. Next, turn the curb key 90 degrees to turn off the water to the home. In some cases, you need to rotate the curb key several times to shut off the flow of water, similar to closing a gate valve.

How to Verify the Water Is Off

Turning off the water shut-off valve or closing the emergency curb stop valve should shut off the water to the house. In some cases, the valve may not function properly, so it’s essential to test the water before proceeding. Go to a sink in the lowest level of the home and fully open the cold water, allowing it to drain into the sink. If the water is off, the flow will slow down before coming to a complete stop.

Next, fully open the hot water and allow it to drain into the sink. Ideally, both the cold and hot water will stop flowing, although sometimes tank-style water heaters may continue to empty indefinitely. If you run into this problem, turn off the isolation valve at the top of the water heater to stop the flow of hot water. Check the sink to verify that the water has stopped.

At this point, you can work on any plumbing project that requires a water shutdown, or you can turn the water back on if you were testing the valve. Make sure to keep the sink tap fully open until after the water has been turned back on. This allows any air in the plumbing lines to exit through the faucet instead of becoming trapped where it can cause water hammer issues.