main shut off valve not working - fix leak

Is Your Main Water Shut Off Valve Not Working? Let’s Troubleshoot!

Are you having problems with your main water shut off valve not working?

In older homes, the shut-off valves for the mainline often are worn and rusted. If your shut-off is upline (closer to the water main) from the valve, you can easily turn off the water and replace the valve. If not, your options are to:

  • live with a less-than-perfect valve
  • pay the water company to shut off your water while you change valves
  • contact a plumber, who can help you with all of this.

But hey, this is a DIY article, so let’s talk about how you can handle this yourself.

Types of Main Shut Off Valves

First, let’s make sure you know the different kinds of valves you could run into. There are three styles (or types) of valves we see used for main water shut-offs. Let’s review them so you know what they are and what to look for.

This is a great video illustrating the basics of shut off valves.

1. Gate Valve

This style of shut-off valve, commonly found in older houses, is not as reliable as a globe or ball valve. You’ll want to replace it if you have the opportunity.

A wedge-shaped brass “gate” screws up and down to control water flow. If it does not fully stop water flow, it cannot be repaired, unfortunately. However, to repair a leak around the handle, replace the packing washer or strand packing.

main water shut off valve not working - gate valve diagram

2. Ball Valve

A ball valve (also called a “quarter-turn” valve) costs more than the other two valves but it is more reliable, intuitive, and easy to shut off quickly. The lever rotates a ball-like gate pierced by an opening. The gate pivots to control the flow of water.

main water shut off valve not working - ball valve diagram

3. Globe Valve

A globe valve (also called a stop valve) works in much the same way stem faucets do. It is more reliable and more easily repaired than a gate valve.

If it does not fully stop water and you can shut off the flow prior to the valve, replace the stem washer. To repair a leak around the handle, replace the packing washer.

main water shut off valve not working - globe valve diagram

Troubleshooting: Main Shut Off Valve Not Working

If the valve handle breaks off in such a way that you can’t easily replace it, use pliers or a pipe wrench to turn the valve off and on. If you want to make sure all household members can turn off the water in case of an emergency, however, you’ll need to replace the valve.

These valves commonly leak from the packing nut whether the valve is open or closed. To troubleshoot and repair, you’ll need about 1 hour but no special plumbing skills. For tools, have on hand a screwdriver, adjustable wrench, groove-joint pliers, and a pipe wrench.

Here’s what you need to do for a main water shutoff valve that’s not working:

  • Tighten the nut gently
  • Don’t apply too much force when tirtening or the valve may crack
  • If the slow drip continues, place a bucket under it and watch it for a day or two. Sometimes, the leak stops on its own.
  • If not, you will need to repack the packing nut.
  • To replace, you can purchase valves that scrfew onto galvanized pipe or brass adapters, or solder onto copper lines.
turning off main water shut-off valve at street with key
Is your main water shut off valve not working? The first step is to shut off the water at the main valve. If you can’t find it in the home, you’ll likely need the city or a plumber to turn off the water from the primary shut-off near the street. A special tool (a key) is used to turn it on and off.

Final Thoughts

The main water shut off valve is one of the most important valves in your entire home. It regulates water coming into the entire house. So, making sure you can fix it if it’s leaking is a great opportunity to do valuable DIY plumbing work.

And now that you know the different types of main shut off valves, you won’t be confused by one if you come across it.

Call 1-Tom-Plumber

If you need help with a main water shut-off valve (or a specific fixture’s shut-off valve), don’t hesitate to contact us here or call us at 1-Tom-Plumber (1-866-758-6237).

1-Tom-Plumber’s certified team of plumbers and drain technicians respond immediately to any emergency plumbingdrain, or water damage problem, including excavation of underground water lines and sewer main lines. Our immediate-response team is available every day and night of the year, even on holidays.

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