Knowing how to properly turn off your water supply is an important skill for any homeowner. When plumbing repairs or replacements are needed, you’ll need to shut off the water flow to prevent leaks and flooding. With the right preparation and tools, turning off your home’s water is a straightforward process.

Locate the Main Water Shut-off Valve

The first step is locating the main water shut-off valve for your home. This allows you to stop water flow from the city water supply into your home’s plumbing system. Here’s how to track it down:

Check the front basement wall or utility room. The main shut-off is often located on the wall where the water service pipe enters the home, either in the basement or a utility room. Look for a large valve on a pipe coming through the wall or floor.

Trace the water meter. In many homes, the main valve is located near the water meter. So follow the inlet pipe to locate the shut-off.

Look for a water meter box. If you have a separate concrete box outside by the street, open it up to see if the valve is inside.

Consult home documents. Any paperwork on the home’s plumbing system may have the valve location noted.

Ask a plumber. If you can’t find the shut-off yourself, contact a professional plumber to locate it.

Ideally, the valve should be easy to access with signs or labels indicating it is the main water shut-off. If not, label it yourself for easier identification later.

Types of Main Water Valves

There are a few common types of valves used for main water shut-offs:

Gate valve – These have a wheel that you turn to lower a round “gate” down over the pipe opening. Turning the wheel clockwise closes the valve.
Ball valve – Ball valves have a lever you turn a quarter-turn to close. With the lever across the pipe, the valve is closed.
Globe valve – Globe valves close by turning a handle to screw a plate down over the pipe. Turn clockwise to close.

Make sure you know what type you have and which way closes it. The valve should be marked with words like “off” and “on” or symbols such as arrows.

Test the Valve

Before you need to use the main shut-off in an emergency, test it to make sure it’s working properly.

To test:

Turn on a faucet in your home to run water.
Locate the main valve and turn it all the way off clockwise.
Check to see if the open faucet has stopped running.
Turn the main valve counter-clockwise to open it again.
Check that the faucet has full water flow restored.

If the main valve is stuck and won’t turn, won’t fully shut off water flow, or leaks, call a plumber to repair or replace it as soon as possible.

Turn Off the Water Supply

When you’ve located the functional main shut-off valve, use the following steps to turn off the water:

Alert anyone in the home you’ll be shutting off the water.
Locate the valve. Bring any necessary tools for access, such as a flashlight or keys to a locked utility room.
Turn off the valve fully. Use both hands if needed and turn it clockwise until tight.
Open a faucet. Choose a sink, tub, or outdoor spigot faucet.
Check water flow. Keep the faucet open and check if the water has stopped flowing. This tests that the valve fully shut off supply.
Flush toilets. Hold down toilet handles to empty any tank water into the bowl.
Turn on the lowest outdoor spigot. This drains the pipes. When it stops flowing, the lines are empty.
Check for leaks. Look at valves, meters, and pipes for any water leaks indicating the valve isn’t fully closed.
Proceed with your plumbing work. With the water supply safely shut off, you can now repair fixtures and pipes without flooding.

With no water flowing through the pipes, they will drain of remaining water over 5-10 minutes. This empties the lines so no water leaks out during your plumbing work.

Turn the Water Back On

When your repair work is complete, restore the water supply:

Confirm repairs are done. Make sure all fixtures and pipes are sealed, intact, and reassembled.
Check for tools and items. Remove any tools or materials from the work area.
Inspect for leaks. Survey valves, meters, and all areas worked on one last time for any leaks.
Turn on a faucet. Open a nearby sink faucet to release pressure as the water comes back on.
Slowly open the main valve. Turn the valve counter-clockwise to restore full water flow.
Check for leaks again. With water flowing through the system, look for any new leaks at connections.
Flush piping. Run sinks, tubs, etc. until water runs clear to purge air from lines.
Test fixtures. Turn on appliances, valves, showerheads, etc. to ensure proper water flow.
Alert residents. Let others in the home know repairs are complete and water service is restored.

Take your time turning the main valve back on and checking your work to prevent flooding from overlooked leaks. If leaks occur, turn the main valve off again for further repairs.

Shutting Off Water to Specific Areas

For some plumbing jobs, you may only need to stop water flow to certain parts of the home rather than the entire supply. Here are ways to shut off sections:

Toilet supply valve – Turn the water valve behind or below the toilet counter-clockwise.
Sink shut-off valves – Locate the hot and cold water valves under sinks and turn them off.
Shower/tub valves – Look for access panels to reach the tub and shower valve stems and turn them off.
Outdoor hose bibs – Use shut-offs on exterior wall faucets to stop outdoor water flow.
Appliance valves – Washing machines, dishwashers and water heaters have individual shut-off valves.
Individual fixture stop valves – Shut valves under each sink and behind each toilet.

Labeling shut-off valves throughout the home makes it quicker and easier to only shut down sections as needed for repairs.

Plumbing Jobs Requiring Shutting Off Water

Some common plumbing repairs that require shutting off the home’s water supply include:

Replacing fixtures – Toilets, faucets, showerheads, dishwashers, ice makers, washing machines, etc.
Re-piping or replacing water lines – Kitchen sink, bathroom, outdoor hose bibs, appliance lines, etc.
Installing water heaters – Storage tank or tankless/on-demand models.
Replacing PRV (pressure reducing valve) – Controls home water pressure.
Repairing or replacing valves – Main shut-off, toilet fill, pressure relief, outdoor spigots, etc.
Fixing leaks – Pipes, joints, valves, fittings, appliances, fixtures, etc.
Installing water filters or softeners – Under sink or whole home filtration/softening systems.
Working on drains and supply lines – Fixing clogs, leaks, rerouting lines.
Updates to the water meter – Installing a new automated meter, for example.

Any time the home’s plumbing system is opened up during repairs, shutting off the main water supply is crucial to avoid flooding, leaks, and water damage.

Safety Tips for Turning Off Water

It’s important to take safety precautions when shutting off a home’s water supply:

Never touch electrical devices while touching wet pipes or water fixtures.
Keep basement areas well lit when shutting valves and inspecting plumbing.
Turn the water on slowly to prevent pressure surges and banging pipes.
Check that the main valve fully seals off water flow.
Monitor shut-off valves for leaks indicating they need repair.
Keep the main valve lubricated with penetrating oil.
Never use pipe wrenches on valve handles, only proper valve keys.
Support hanging pipes when emptying the system so joints don’t detach.
Let residents know before turning off water so they can prepare.

Understanding the proper procedures for shutting down your home’s water supply will give you confidence to take on plumbing repairs yourself or assist repair workers. While turning off house water can seem intimidating, these steps make the process straightforward and safe for your plumbing system.

Frequently Asked Questions About Turning Off Water for Plumbing Repairs

How long can I leave the water off during repairs?

It’s best to minimize the time water is shut down. Complete repairs as quickly as possible, within 8-12 hours. Notify residents so they can plan around outages.

Do I need to shut off water at individual fixtures?

If you shut the main valve, that stops all water, so individual fixture valves are optional. They can isolate problem areas.

How do I drain the pipes to remove all the water?

Opening lowest faucets will drain out gravity-fed lines. For pressurized pipes, attach compressed air to lines to force remaining water out.

What if I can’t find the main water shut-off valve?

Contact a professional plumber to locate the valve if you can’t find it. All homes should have a main shut-off, so keep looking. Check with your city if it’s at the street.

Are there any dangers with restoring water service?

Air in lines and pressure changes can cause pipes to bang when restoring service. Open valves slowly and run taps until air is purged to prevent damage.

How do I keep the main water valve in working order?

Periodically operate the main valve to prevent it from seizing up. Keep it accessible. Lubricate the valve stem annually with penetrating oil. Replace worn out valves.

Can I turn off just hot or just cold water piping?

No, main valves shut off the full water supply. But you can use individual shut-offs on some hot water and cold water lines if needed.

What if shutting off water impacts medical devices or equipment?

Alert anyone using medical devices that require water before shutting it off. Inexpensive battery-powered emergency shower/tub units can be used for necessity.

How will I know when the pipes are fully drained?

Open taps will sputter air and slow to a stop when empty. Pipes will gurgle as air enters. It takes longer for horizontal runs. Verify by checking for drips at fittings.

Conclusion

Knowing how to safely shut down the water supply to your home plumbing system is a useful skill for any homeowner. Before tackling repairs, locate your main water shut-off valve and test that it fully stops the flow of water when turned off. Use these steps outlined to turn off the water, drain pipes, complete your plumbing work, and restore normal water service. Taking precautions for safety and to prevent flooding or leaks will lead to a successful repair project. Be sure to alert other household members when the water will be turned off so they can prepare. With the right information and preparation, you can confidently shut off your home’s water when plumbing work calls for it.

How to Turn off the Water for Plumbing Repairs