How to Shut Off Water to a Single Fixture: Stop Valve Basics

TL;DR: Almost every sink, toilet, dishwasher, and washing machine has its own dedicated shutoff valve nearby, usually a small oval or lever handle on the supply line. Turn it clockwise to close, and test it once a year so it isn't frozen shut when you actually need it during an emergency. If a fixture has no valve or the valve won't turn, you'll have to use the main shutoff until it's replaced, which usually costs $75-$200 for a plumber.

_Last reviewed: July 2026 · 6 min read_

A supply line splits under the bathroom sink and water is spreading across the floor. Most homeowners' first instinct is to run for the main shutoff in the basement, but that cuts water to the whole house. There's almost always a smaller valve a few inches from the leak that would have handled it in five seconds.

Okoniq Property Hub lets you log where every stop valve is in a property, so you're not hunting under cabinets during an actual leak.

Where do I find the stop valve for a fixture?

The stop valve, sometimes called an angle stop or fixture shutoff, sits on the supply line between the wall and the fixture. For a sink, it's in the cabinet below, usually two of them if there's hot and cold. For a toilet, it's on the wall or floor behind the base, a single valve since toilets only use cold water. For a washing machine, it's usually a pair of valves on the wall where the hoses connect, sometimes behind an access panel. For a dishwasher, the valve is often under the kitchen sink, feeding a separate line that runs behind the cabinets.

Older homes built before the 1960s sometimes skipped individual valves altogether, especially for toilets. If you can't find one, that's worth noting as a repair project rather than an emergency fix, since it means any leak at that fixture requires the main shutoff instead.

How do I actually turn off a stop valve?

Turn the handle clockwise, "righty tighty," until it stops. Most residential stop valves are quarter-turn ball valves with a lever handle, so a 90-degree turn from parallel-to-the-pipe to perpendicular closes it fully. Older compression valves use a round or oval knob and need several full rotations, similar to an outdoor spigot.

Don't force a valve that resists after the first firm turn. Old multi-turn valves, especially ones over 15-20 years old, can seize from mineral buildup and shear off the stem if you crank hard. If a valve won't budge with moderate hand pressure, stop and treat it as a valve that needs replacing rather than fighting it mid-emergency.

What if the valve won't turn or there isn't one?

If the valve is frozen or missing, your options are the main shutoff or a plumber, and neither is fast enough for an active leak. The whole-house main is typically in the basement near where the water line enters, in a utility closet, or near the water meter for slab homes. Shutting it off stops water everywhere, including to the water heater, so it's a stopgap, not a fix.

Replacing a stuck angle stop is a straightforward job for a plumber, usually $75-$200 depending on the fixture and whether the old valve has to be cut off the pipe. It's cheaper to do this on your own schedule than at 11 p.m. during a ceiling water stain emergency. If the supply lines themselves are old galvanized or original builder-grade plastic, this is also a reasonable time to swap them for braided stainless lines, which resist bursting far better over a 10-year span.

| Situation | What to Do | Typical Cost | |---|---|---| | Valve turns freely | Shut clockwise, done in seconds | $0 | | Valve is stiff but moves | Shut it, then schedule replacement | $75-$200 | | Valve won't move / missing | Use main shutoff, call plumber | $75-$200 |

How often should I test fixture valves?

Test every stop valve in the house once a year, ideally in spring when you're already doing seasonal checks. A valve you haven't touched in 10 years is more likely to be frozen or leak once you finally turn it, since the rubber washers and seals dry out from disuse. Turn each valve fully closed, then fully open again, and watch for any drip at the packing nut where the handle meets the valve body.

While you're under there, check the supply lines themselves for cracking, bulging, or mineral crust, especially on toilets where an undetected slow leak can run for months unnoticed. If a valve drips even slightly when you test it, that's your signal to replace it before it fails on its own timeline.

Should I upgrade old valves before they fail?

Yes, if your home still has multi-turn compression valves and it's been more than 15 years since they were installed, budget for quarter-turn ball valve replacements. Ball valves are more reliable long-term, easier to operate for anyone with weaker grip strength, and give a clear visual cue (handle parallel = open, perpendicular = closed) instead of guessing how many turns closed a compression valve. A plumber can usually swap 4-5 valves in a single visit for somewhere between $300-$600 total, which is far less disruptive than an emergency call when one fails during a cast iron drain pipe repair or renovation.

FAQ

Which way do you turn a shutoff valve to close it?

Clockwise closes almost all residential valves, following the standard "righty tighty, lefty loosey" rule; for lever-handle ball valves, a quarter turn until the handle sits perpendicular to the pipe means it's fully shut.

Can I use pliers on a stuck stop valve?

Light pressure with channel-lock pliers is fine, but if it doesn't move with a firm hand grip plus a bit more from pliers, stop, since forcing it risks shearing the stem and turning a stuck valve into a broken one that floods the area anyway.

Do all toilets have a shutoff valve?

Most toilets installed after the 1970s have one, but some older homes and a surprising number of newer rental units skip it, meaning you'd need the main shutoff for any toilet-related leak until one is added.

How much does it cost to add a shutoff valve where there isn't one?

Expect $100-$250 per fixture for a plumber to cut into the supply line and install a new angle stop, more if the existing pipe is old galvanized and needs adapting to modern connections.

Is it safe to leave a stop valve closed for a long time, like during a vacant rental period?

Yes, closing individual fixture valves for weeks or months is safe and actually reduces leak risk while a unit sits empty, though it's worth reopening and testing them before a new tenant moves in to confirm nothing seized shut.

This is educational information, not plumbing advice. Call a licensed plumber if a valve won't close, if you suspect a slab leak, or if you're unsure about cutting into an existing supply line.