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How To Shut Off a Water Main / Water Supply

Plumbing Emergencies

Everyone should take the time to find their main water shut off valve. If a pipe bursts, an extra two minute delay can result in 30 or more gallons of spilled water. That is roughly the equivalent of a bathtub full of water. That much water, inside your home can cause a lot of damage. Being able to find the shut off valve and a wrench quickly can save you thousands of dollars of damage.

Caution: Please read our safety information before attempting any testing, maintenance or repairs. Some equipment may rely on a cold water supply. Take appropriate steps to shut down any equipment that may be adversely affected by shutting off the water supply. Such equipment includes, but is not limited to, a boiler or other heating system.

Most homes which draw their water from a municipal supply will have a water meter and shut off valve grouped together. That water meter is often located near the street, in an under ground access hatch. Lift the cover and you will find either a handle, or a valve with a straight metal flange across the top. The handle may be rotary, like a manual sprinkler valve or it may be a paddle. Turn the rotary or paddle until it won't turn any further. Valves that have a metal flange require a pipe wrench to operate. This type of valve closes with just a quarter turn. If a wrench is required, we recommend leaving a wrench near the valve for emergency use.

The hose bib in front of this house has, from the bottom up, the incoming municipal water supply, a water pressure regulator, a shut-off valve and a hose bib with an anti-siphon valve attached. The water line T's and goes into the residence.

Many homes have additional shut off valves that can shut off localized sections of the water supply. For instance, where the water main enters your house, you will often find a hose bib and a shut off valve. In cold weather locations, the shut off may be in the basement or inside the house, possibly under the kitchen sink or under a closet floor. This valve will typically shut off all water inside the house but may leave the outside plumbing unaffected (such as hose bibs, sprinklers, accessory buildings). This valve is most often a rotary type. We recommend that you open and close it once a year to help prevent it from seizing in the open position.

Inside your home you will find more shut off valves localized to the fixtures that use them. Some examples include the water heater, sinks, dishwasher, washing machine and toilets.

If you are unable to locate or unable to access your main water shut off valve, contact your water company. Your local water company will usually be very helpful and may even send someone out to help you find the valve and show you how to shut it off.

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