How to Turn Off the Water to Your House

Water enters your house through a single cold water line. Shutting off this line will stop the water pressure in the house but doesn’t do anything about the water that is already in the pipes when the pressure is turned off.

As the water lines proceed through the house, branch lines move water from this main line to outlets like sinks and toilets. If there is a leak in a cold water line, water to the entire house will need to be turned off unless there is a valve at the point of use.

At some point, water is diverted from the cold water line to the water heater. This is where the hot water lines begin. If there is a leak in a hot water line, you can turn off the water at the water heater and still have cold water to use. When turning off cold water to the entire house, power to an electric water heater should be turned off as well. Check the operator’s manual about the requirements for turning off your water heater when the water is off and for the procedure to follow.

There are two main types of shutoff valves, gate and ball. Ball valves are often called quarter turn, because they only require 1/4 turn to operate.

A gate valve needs to be turned several times to completely open or close it. Any valve can seize over time but gate valves are more prone to seizing than ball valves. These valves should be exercised on a regular basis to maintain function. Turn the knob clockwise (to the right) to close and counterclockwise (to the left) to open. The old saying "righty-tighty, lefty-loosey" works with valves just like nuts and bolts.

A ball valve does its job with just 1/4 of a rotation. They often have a lever rather than a knob. These valves usually require less maintenance but do need to be exercised from time to time. If the handle looks like a lever, the valve is open if the handle is aligned with the valve body and closed if it is perpendicular.

When closing the valve, pay attention to how smoothly it operates and if it leaks. If it’s seized, difficult to operate, leaks or doesn’t shut off the water, it needs to be rebuilt or replaced. In this case, your water utility will need to shut off, to turn off the water, so the work can be done.

Don’t use a tool like a pipe wrench to force a non-functional valve handle to turn. There’s a good chance it will break and cause another problem. If a tool is necessary to turn the valve handle because of a physical limitation, be careful not to apply enough force to break the valve. Look for signs of bending, breaking or leaking.

A house’s water valve is often located at the point where the water pipe enters the house. It will usually be on the same side of the house as the water meter. This means that you should start your search on the front side of the house. The water line could encircle the house and come in through a side or rear wall but this wouldn’t be common.

The valve may be in a buried access box outside the foundation or on an interior wall in the basement or crawl space. In some warm climates, it is common for the valve to be outside of the home, on a pipe that leads into the foundation. Another place to look is in the back of a closet on the side of the house that is close to the water meter. In cold climates, it should be inside of the house or foundation.

The main shutoff valve will not look the same in every situation. At the meter, it often looks like a valve that's missing its handle. Many older systems will use a gate valve with a round knob handle that is 2-4 inches in diameter. Newer systems may be a larger version of a ball valve.

In some homes, such as those on a slab without a basement or crawl space, the water valve is at the utility’s meter. Opening the meter box may require a meter key or other tool. Operating this valve often requires a tool called a “curb key.” This tool doesn’t resemble a regular key, it looks like a large metal “T” with a notch at the bottom end.

To turn off water with a curb key, open the water meter box and find the valve. It will appear as though the handle is missing. The curb key is the handle. Place the notched end of the key over the “missing” handle and turn the valve in a clockwise direction until it stops. There should be no need to crank down on it.

If your water comes from a well, there are several ways to shut off water to the house.

• Electrical power to the well can be shut off. This is normally done by switching off the breaker to the well pump in the house.
• There could also be a switch or a fuse box at the well.
• The pressure switch may have an external switch to control the pump. Do not remove the cover to the pressure switch unless the electrical power has been turned off at the source.
• There should be a valve at the well to stop the flow of water to the house.

Once you know how to turn off the water to the entire house, it becomes evident that turning off water at each point of use would be beneficial.

Many fixtures and appliances that use water will have a shutoff at the base of the supply line. This valve is often called a “stop” or “angle stop,” depending on its configuration.

Similar to the main line shutoff, stops can be multi-turn gate valves or 1/4 turn ball valves. The same general rules apply. If the valve is seized or if it leaks, it should be replaced or repaired.

Other common water shut off valves in a house:

• Toilets
• Sinks
• Water heater

Tip: Turn off the power to the water heater if turning off the water. If a leak is in the hot water line, turn off the power to the water heater. If an electric water heater tries to heat water that isn’t there, it can burn up the elements and require a costly repair.