How to Turn Off Water Supply for Faucet Replacement

Step 1: Locate the Shutoff Valves

Open the cabinet doors under your sink and look for the supply lines—flexible tubes (usually braided stainless steel or white plastic) that connect from the wall or floor to the bottom of your faucet.

Where these lines connect to the wall or floor pipes, you should see shutoff valves. There are two:

• Hot water valve: Usually on the left side (facing the sink)
• Cold water valve: Usually on the right side

Step 2: Identify Your Valve Type

There are two common types of shutoff valves:

Gate Valves (Multi-Turn)

These have a round knob that requires several full rotations to close. They're the older style and more common in homes built before 2000.

• How to close: Turn clockwise until it stops (usually 5-7 full rotations)
• Common issue: Can get stuck or corroded if not used regularly

Ball Valves (Quarter-Turn)

These have a lever handle that only needs a 90-degree turn to close. They're the modern standard and much more reliable.

• How to close: Rotate handle 90 degrees so it's perpendicular to the pipe
• Easy check: Handle parallel to pipe = open, perpendicular = closed

Step 3: Clear the Area

Before turning anything:

• Remove all items from under the sink
• Place a towel or shallow pan under the valves
• Have a flashlight ready—it's dark under there
• Keep a bucket nearby just in case

Step 4: Close Both Valves

Close both the hot and cold water valves:

1. 1.Start with one valve (doesn't matter which)
2. 2.Turn clockwise until it stops completely
3. 3.Don't over-tighten—firm is enough, excessive force can damage the valve
4. 4.Repeat for the other valve

Step 5: Verify Water Is Off

Always test before disconnecting anything:

1. 1.Turn on the faucet at both hot and cold settings
2. 2.Water should slow to a trickle then stop within a few seconds
3. 3.A small amount draining is normal—that's water already in the lines
4. 4.If water continues flowing—the valve isn't fully closed or isn't working

What If Valves Are Stuck?

Old gate valves often seize up from years of non-use. Here's what to try:

Step 1: Apply Penetrating Oil

Spray WD-40 or PB Blaster around the valve stem where the handle meets the body. Let it sit for 15-20 minutes.

Step 2: Try Again with Gentle Pressure

Use an adjustable wrench for better grip, but apply gradual pressure. Don't jerk or force—you're trying to break through corrosion, not break the valve.

Step 3: Work It Back and Forth

If it moves at all, turn it slightly in both directions to help free up the threads, then gradually close it.

Step 4: If Still Stuck—Stop

If the valve won't budge after these steps, you have two options:

• Shut off water at the main: Find your home's main shutoff valve (near the water heater, in the basement, or at the street) and close it there
• Call a plumber: Have them replace the stuck valve as part of the faucet installation

Consider Replacing Old Valves

If your shutoff valves are:

• Old-style gate valves (multi-turn knobs)
• Corroded or discolored
• Dripping when fully closed
• Difficult to turn

This is an excellent time to upgrade to quarter-turn ball valves. They're more reliable, easier to operate in emergencies, and last longer. A plumber can typically replace both valves for $150-250 while doing your faucet install.

Finding Your Main Water Shutoff

If you need to shut off water at the main:

In Cold Climates

• Basement or crawl space: Look where the main water line enters the house
• Utility room: Near the water heater or water softener
• Near the foundation wall: On the side facing the street

In Warm Climates

• Outside near the foundation: Often in a covered box
• Near the water meter: Usually at the property line
• In the garage: If you have an attached garage

After Shutting Off Water

With the water off and verified, you're ready to:

1. 1.Disconnect the supply lines from the faucet
2. 2.Remove the old faucet
3. 3.Clean the sink surface
4. 4.Install your new faucet

Keep a towel handy during disconnection—some water will drain from the supply lines and the faucet itself.

FAQ