How often should you test your main water shutoff valve?
Updated July 2026
Exercise your main water shutoff valve once a year by closing it all the way and reopening it, so it does not seize in place after years of sitting untouched. The day you actually need it, a burst supply line or a failed water heater, is the worst possible moment to find a frozen valve. A supply break can push 5 to 10 gallons a minute into the house, and while you hunt for the street shutoff, that becomes thousands of gallons across the floor.
What changes the interval
| Your situation | Interval | Why |
|---|---|---|
| Quarter-turn ball valve (lever handle) | Test once a year | Reliable, but a quick yearly turn keeps it free |
| Old gate valve (round wheel handle) | Test yearly, plan to upgrade | Gate valves seize and snap; a ball valve is the fix |
| Valve in an unheated crawlspace or garage | Twice a year | Cold and damp corrode the stem faster |
| Handle is stiff or weeps at the stem | Replace it now | A valve that barely turns will not close when it counts |
| Leaving town for a week or more | Shut it off entirely | An empty house means any leak runs until you return |
| Home over 30 years old, valve never touched | Have a plumber exercise it | Decades-old valves can break the first time they move |
The cost of skipping it
What skipping it costs: water-damage claims are among the most common and expensive homeowner losses, routinely running well into five figures once flooring, drywall, and cabinets are soaked. All of that hinges on one valve turning when you need it. Upgrading a seized gate valve to a quarter-turn ball valve is $150–350 installed, cheap insurance for a shutoff that works. Leaving town without closing it is how a pinhole leak becomes a vacation-long flood.
How to do it (5 minutes · DIY, no tools)
- Find the main shutoff: usually where the water line enters the house, near the water meter, in a basement, crawlspace, garage, or an outside box.
- Turn a lever valve a quarter turn until it is perpendicular to the pipe, or turn a wheel-handle valve fully clockwise until it stops.
- Open a low faucet in the house and confirm the flow drops to nothing, proving the valve actually closed.
- Reopen the valve fully, then back a wheel handle off a quarter turn so it does not bind on the seat.
- Watch the valve body and stem for any drips over the next few minutes; weeping means it needs repacking or replacement.
- While you are there, note where the street or curb shutoff is, and consider checking your home water pressure.
Knowing the interval is the easy half. OnOtto reminds you at the right interval, and it won't let you snooze it into next year. Tasks persist until they're done, and completing main shutoff tests schedules the next one automatically.
Put this on autopilot, free for 30 daysFrequently asked questions
Where is my main water shutoff valve?
Follow the water line from the meter into the house; the main shutoff is usually within a few feet of where it enters. In cold climates it is typically in the basement or a mechanical room; in warmer regions it may be in a garage, a crawlspace, or an exterior box near an outside wall. There is often a second shutoff at the street (the curb stop) that the utility controls. Know both, and keep the path to the indoor one clear.
What if the valve will not budge or leaks after I turn it?
Do not force a stuck valve with a wrench, since old gate valves can snap the stem off and leave you unable to shut the water at all. If it is frozen, weeping at the stem, or will not fully close, call a plumber to replace it, ideally with a quarter-turn ball valve. That is a $150–350 job and far cheaper than discovering a dead valve mid-emergency. A minor stem weep can sometimes be fixed by snugging the packing nut.
Should I also know where the street or curb shutoff is?
Yes. The curb stop out near the street or sidewalk shuts off water to the whole property, and it is your backup if the interior valve fails. It usually sits under a small metal or plastic lid and takes a long curb-key tool to operate. Locate it before you need it. In many towns the utility prefers you call them to operate it, but in a true emergency, knowing exactly where it is saves precious minutes.
Gate valve or ball valve, which do I have and does it matter?
A gate valve has a round wheel handle you spin many turns; a ball valve has a straight lever you swing a quarter turn. It matters a lot: gate valves are the ones that seize, corrode, and snap after years unused, and they often fail to fully stop flow even when closed. Ball valves are far more reliable and give instant, positive shutoff. If you have an aging gate valve on the main, budget to upgrade it.