Shutting Off Your Water Main in an Emergency

May 11, 2021

Facing an emergency and need to shut off your water main? Your home’s main water supply has a shut off feature that you should know about. A single burst pipe or sewage backup can cause extensive damage and cost thousands of dollars in wasted water and repairs. There’s often little time to act when a pipe breaks; the problem is usually behind drywall or other hard-to-reach location. Knowing where the main water shutoff is and how to use it can save you a lot of trouble.

Where Is the Main Water Shut Off Valve?


There is no standard as where the water supply valve should be. One is often installed near the front of the house, on an interior wall (or exterior wall facing the street in warm climates), close to the water meter. It may be in the basement, garage, or laundry room. Basement valves are typically at eye level while those on main floors are usually lower.

For homes built on a slab, it could be in the garage or near the hot water heater.

Some valves aren’t inside the home, but rather in a covered box dug in the ground somewhere along your property line. This cement box is often near a front curb and requires a key to be opened. Such keys can be found at popular hardware stores.

In addition to a main shutoff, toilets, sinks, washing machines, water heaters, and other plumbing fixtures have their own valves to shut off their water supply. These are usually simple valves that look like small round or oval knobs. To turn these off, simply turn them clockwise to shut off the flow.


How to Use the Water Supply Valve


There are two types of water supply valves:

  • Gate: Turn the gate or “wheel” clockwise to stop the flow of water.


  • Ball: Turn the level clockwise 90 degrees; in the “on” position, it will face straight down and when off, will face perpendicular to the pipe.

Isolation valves are controlled in a similar way. But when you adjust the shutoff valve, leave the pressure regulator alone; it should only be adjusted by a licensed plumber to control water pressure. If the valve is in an outside box, turn the key counter-clockwise, tilt it towards the outer edge, and lift the lid. Turn off the water with a clockwise ¼ turn of the ball valve and don’t tamper with the city shut-off side, which is illegal.


What to Do Once You’ve Shut Off the Water Valve


Once you have verified the shutoff valve has been turned off, run the hot/cold taps of a sink faucet at the lowest floor. Any water in pipes from above will drain and relieve pressure. Repairs can now be made. Once they are complete, twist the valve counterclockwise to restore water flow. Faucets may have to be left on for a few minutes before water reaches them.

However, if the problem is limited to a single fixture, you can shut it off and continue using the rest of your plumbing while the appliance is being fixed.


Call Elmer’s Air Conditioning and Plumbing for Help


We specialize in plumbing installation, maintenance, and repair in San Antonio, TX. Our emergency plumbers are available 24/7 to find and fix problems and avoid major water damage. By knowing the location and proper use of your water main shutoff valve, you can protect your home between the time you call and when we arrive. To request service, reach out to us online or call 210-333-5637 today!

If you are experiencing any of the signs that your water heater needs repair or replacement, don’t hesitate to call a professional.

Elmer’s Home Services in San Antonio TX can help you assess the situation and make the best decision for your needs. We have experienced plumbers and quality service, so you can get back to enjoying hot showers and baths in no time. 

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San Antonio, TX 78233

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Our business provides water heater repair, emergency plumber services, and plumbing repair in San Antonio, Texas. We have proudly served over 20,000 customers. Our professional plumbers are punctual and take pride in providing reliable and affordable home services to our neighbors.

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