How to Shut Off Water to Your House (Step-by-Step)

A burst pipe, overflowing toilet, or leaking appliance can dump hundreds of gallons of water into your home in minutes. Knowing how to shut off your water supply before a crisis happens is one of the most valuable things a homeowner can learn — and it takes less than five minutes to locate your valve today.

Where Is the Main Water Shutoff Valve?

Your main shutoff valve controls all water entering your home. Common locations:

• Basement: On the wall facing the street, usually near the foundation where the water line enters
• Crawl space: Near the access hatch, along the perimeter wall closest to the street
• Utility room: Near the water heater or laundry area
• Garage: Along the wall closest to the street
• Outside: In an underground box near the curb (the "curb stop" — usually requires a special key)

If you're in a home built before 1980, it may be a gate valve (round wheel). Newer homes typically have a ball valve (lever handle). Ball valves are faster — a quarter turn closes them completely.

How to Shut Off the Main Water Supply

Ball valve (lever handle):

1. Locate the lever — it should be in line with the pipe when open
2. Turn the handle 90 degrees (perpendicular to the pipe) to close
3. That's it — water is off

Gate valve (round wheel):

1. Turn clockwise ("righty tighty") until it stops
2. These can take 5–10 full rotations
3. If it hasn't been turned in years, it may be stiff or stuck — use both hands

After shutting off:

• Open a faucet on the lowest floor to release pressure and drain remaining water
• The hot water heater will still have water — don't run it while supply is off
• Call a plumber if the valve is stuck, corroded, or leaking at the stem

Individual Fixture Shutoff Valves

You don't always need to cut the whole house. Individual shutoffs let you isolate one problem:

Under Sinks

Oval or oval-shaped handles beneath every sink — one for hot, one for cold. Turn clockwise to close. Useful for faucet leaks or running toilets.

Behind Toilets

A small oval knob on the wall or floor behind the toilet. Turn clockwise to close. This alone stops most toilet-related flooding.

Water Heater

Two valves on top — one on the cold supply line (usually blue or labeled "cold in"). Close this to isolate the heater without cutting the whole house.

Washing Machine

Two hose bib valves behind the machine. Turn both clockwise to close. Should be closed whenever the machine is unattended for extended periods.

Refrigerator Ice Maker

A small saddle valve on the cold water line under the kitchen sink or behind the fridge. Turn clockwise to close.

The Curb Stop (Emergency Backup)

If your main shutoff fails or you can't locate it, the curb stop is the last resort. It's in a buried box near the street, usually marked with a metal cover flush with the ground.

• Requires a "water meter key" or long-handled shutoff tool (available at hardware stores for ~$20)
• In true emergencies, the utility company can shut it off — call them
• Don't use the curb stop routinely; leave it for the utility company to operate

What to Do After a Water Emergency

1. Shut off the water immediately
2. Turn off electricity in affected areas if water is near outlets or panels — safety first
3. Document all damage with photos before cleanup (critical for insurance)
4. Call your insurance company within 24 hours
5. Extract standing water as fast as possible — mold begins colonizing in 24–48 hours per IICRC S500 guidelines
6. Call a licensed plumber to locate and repair the source

Seasonal Shutoffs

Vacation: If you'll be away more than a few days, especially in winter, shut off the main and drain the lines. Frozen pipes can burst silently while you're gone.

Winter freeze warning: If temps drop below 20°F and pipes aren't insulated, proactively shut off water to outdoor spigots using their individual shutoffs and let those lines drain.

Irrigation systems: Have a dedicated shutoff — close it before the first freeze and open after the last frost.

Finding a Hidden Shutoff Valve

Can't find your valve? Try:

• Checking your home inspection report — valves are typically noted
• Looking at your water meter: trace the pipe from the meter toward the house
• Asking a plumber during your next service call to locate and label it
• Installing a clearly-labeled tag on the valve once found

When to Replace Your Shutoff Valve

Replace the main shutoff if:

• It doesn't fully stop water flow when closed
• The handle or wheel is corroded and won't turn
• It leaks at the stem packing
• It's a gate valve (upgrade to a ball valve for reliability)

Valve replacement costs $100–$300 with a plumber, or up to $500 if access requires cutting drywall. Worth it for peace of mind.

Key Takeaway

Right now, before you finish reading this: go find your main shutoff valve, make sure it turns, and show everyone in your household where it is. Label it with a tag if needed. In a water emergency, every second counts — and the homeowner who knows where the valve is stops hundreds of dollars in water damage before a plumber even picks up the phone.