When water is gushing, shut off the fixture valve first (under the sink or behind the toilet), and if that fails, close the main house shut-off valve — usually near the hose bib at the front of the house or in the garage. Turn it clockwise until it stops, then open a low faucet to drain pressure.
- Fixture shut-off valves stop water at one sink, toilet, or appliance — try those first.
- The main house valve is typically at the front hose bib or in the garage where the line enters.
- Turn valves clockwise to close; a stuck gate valve should never be forced with a wrench.
- After shutting off, open the lowest faucet in the house to relieve pressure and drain the lines.
- Find and test your main valve today — before you need it at 2 AM.
Where is my main water shut-off valve?
In most San Gabriel Valley homes the main shut-off sits in one of two places: on the pipe feeding the front hose bib, or on the wall inside the garage where the water line enters. Homes built on a slab (most of Glendora, Covina, and Azusa) usually have the valve where the supply line rises out of the ground at an exterior wall.
The concrete box at the curb belongs to the water utility — leave it to the utility or your plumber. The house-side valve is the one you should know and use.
How do I turn the water off?
Two valve styles are common. A ball valve has a lever handle — turn it a quarter-turn so the handle sits perpendicular to the pipe. A gate valve has a round wheel handle — turn it clockwise until it stops. Older gate valves seize over time; if yours won't budge by hand, don't force it with a wrench. The stem can snap and turn a leak into a flood.
Once the main is closed, open the lowest faucet in the house (a tub spout or an outdoor bib) to drain the remaining pressure out of the lines.
When should I use a fixture valve instead?
If the problem is one fixture — a running toilet, a leaking supply line under the kitchen sink, a failed washing machine hose — close the small oval or football-shaped valve on the wall behind that fixture instead. You keep water to the rest of the house while the problem waits safely for a repair. Our guide to spotting hidden leaks covers what to check once the water is off.
What should I do after the water is off?
Move standing water fast — towels, a wet-vac, fans. Water that sits more than a day invites mold, and drywall and flooring soak it up quickly. Photograph the damage for insurance before you clean up, and leave cabinet doors open so the space can dry.
Then call a plumber. A burst pipe, slab leak, or failed water heater doesn't fix itself, and reopening the main before the repair just restarts the flood. Our 24-hour emergency plumbing team answers around the clock, every day of the year.
How can I prepare before an emergency happens?
- Find your main valve today and show every adult in the house.
- Exercise the valve once or twice a year — close and reopen it so it never seizes.
- Replace rubber washing-machine hoses with braided stainless lines.
- If your main valve is a corroded gate valve, have it upgraded to a quarter-turn ball valve — it's a small job that pays for itself the first time you need it.
- Tag the valve with a bright zip tie or label so anyone can find it under stress.
The Environmental Protection Agency estimates household leaks waste nearly 10,000 gallons of water per home every year — knowing your shut-offs is the first step to catching problems early.
About this guide
From the Good News Plumbing & Drain Inc. team — family-owned and serving the San Gabriel Valley since 2001. California C-36 License #906746 (verify it at cslb.ca.gov), bonded & insured, and backed by our satisfaction guarantee. Guidance reflects the plumbing we repair and install across the Valley every week. Last reviewed July 16, 2026.
Sources & standards
Common questions
Is it safe to shut off the water at the meter box myself? +
No — the meter box at the curb belongs to the water utility, so leave it to the utility or a licensed plumber. Use the house-side main valve instead, and if you can't find or turn it, call our 24-hour line and we'll walk you through it on the way over.
My main shut-off valve won't turn. What do I do? +
Stop — don't force it. Seized gate valves snap easily, and a broken stem means the water can't be shut off at all. Close the fixture valve if you can, and call a plumber to replace the main valve with a modern quarter-turn ball valve.
Does shutting off the water also shut off the water heater? +
Closing the main stops cold water from feeding the heater, but the tank stays full and hot. If the water heater itself is leaking, also close the dedicated cold-inlet valve on top of the tank and turn the gas control to OFF (or flip the breaker on an electric unit).
