Where Is Your Main Water Shutoff? A Los Gatos Homeowner’s Guide

When a pipe bursts or a supply line under the sink lets go, the first few minutes matter more than anything else. Drywall starts wicking water upward within the hour, and hardwood floors can cup within a day. The fastest way to stop the damage is to shut off the water to the whole house, and that only works if you already know where the shutoff is.

After more than 38 years of plumbing calls around Los Gatos, we can tell you the most stressful ones usually start the same way: water running, and nobody in the house sure where to turn it off. Here’s how to find yours on a quiet weekend, so you’re ready if the day ever comes.

Where to Look in a South Bay Home

Most homes in Los Gatos, Saratoga, Monte Sereno and Campbell have the main shutoff in one of a few places:

• Near the front hose bib. Many homes have the main valve on the pipe where the water line comes up out of the ground and into the house, often next to the outdoor faucet facing the street.
• In the garage. Especially in homes where the water heater is in the garage, the main line sometimes enters there.
• At the meter box by the sidewalk or street. This is the water company’s box, and it has its own valve.
• In the crawl space. Some older homes near downtown Los Gatos have the main valve under the house.

Homes up in the hills often have a longer run of pipe between the meter and the house. If that’s you, it’s worth finding both the valve at the house and the meter box, since a leak on the line in between can only be stopped at the meter. We cover more about hillside plumbing in our guide to plumbing in the Los Gatos mountains.

Know Which Kind of Valve You Have

• A round wheel handle (a gate valve) closes by turning it clockwise, usually several full turns until it stops. Older homes often have these.
• A lever handle (a ball valve) closes with a quarter turn. When the lever sits crosswise to the pipe, the water is off.

Turn it firmly, but don’t force it. A valve that hasn’t moved in twenty years can stick, and forcing an old valve can break it. If yours won’t budge, that’s a sign it should be replaced before an emergency, not during one.

Test It Once a Year

Pick a quiet morning, close the main valve, and open a faucet to make sure the water actually stops. Then open the valve back up. If it’s stuck, leaks around the stem, or doesn’t fully stop the water, give us a call and we’ll come out and take a look. Swapping an old gate valve for a quarter-turn ball valve is a quick job, and it makes shutting the water off something anyone in the house can do.

The Smaller Shutoffs Worth Knowing

You don’t always need to shut off the whole house. Most fixtures have their own valve:

• Toilets: the small valve on the wall or floor behind the toilet.
• Sinks: two small valves under the sink, one for hot and one for cold.
• Water heater: the valve on the cold water line at the top of the tank.
• Washing machine: the two valves behind the washer, usually in a small box on the wall.

Rubber washing machine hoses and old braided sink lines are some of the most common causes of sudden leaks we see. If yours are original to the house, they’re worth checking.

If Water Is Running Right Now

1. Close the main shutoff (or the fixture valve if the leak is at one fixture).
2. Open a cold faucet at the lowest point of the house to drain the water left in the pipes.
3. If the water heater is leaking, turn off its gas or power and close the cold water valve above it.
4. Call us at (408) 358-6446. If you can’t find the shutoff, we’ll talk you through it on the phone.

Our shop is on Capri Drive here in Los Gatos, and we handle 24/7 emergency plumbing across Los Gatos, Saratoga, Monte Sereno and Campbell. If you suspect a hidden leak rather than a burst pipe, our leak detection page explains the signs, and if the problem is the line from the street to your house, see water line repair.

Finding your shutoff takes five minutes. Do it this weekend, and show everyone in the house where it is.