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Test for Leaks — Install the New Faucet

Beginner2 hours

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Faucet Replacement: A Step-by-Step DIY Guide · Step 3 of 3

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Once all connections are tight, wipe away the excess plumber's putty from inside the sink basin. Turn on the faucet and let water run for a minute or two to test the new installation. Carefully inspect all the connections underneath the sink—the mounting nut, the P-trap connections, and the wall connection—for any signs of dripping or leaks. If a leak is found, gently tighten the corresponding nut slightly until the drip stops.

Goal: Ensure a leak-free installation

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  • Rag or Paper Towel (brand: Unspecified, Tool Type: Cleaning Tool, Power Source: Manual)Wiping away excess plumber's putty and drying connections to check for leaks.
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FAQs

Do I really need a basin wrench for this project, or can I use a standard adjustable wrench?

While an adjustable wrench can handle some tasks, a basin wrench (like the TEKTON WRN92004) is highly recommended. Its specialized design allows you to easily reach and tighten nuts in the tight, awkward space under the sink, making the process much smoother and preventing frustration, especially for beginners.

What should I do if the water supply valves under my sink are stuck, corroded, or leaking when I try to turn them off?

If your shut-off valves are stuck or leaking, do not force them, as this could cause a more significant leak. You might need to turn off the main water supply to your house to prevent flooding. This usually indicates that your shut-off valves need replacement, which is a separate project best addressed before installing a new faucet.

I've installed my new faucet, but it's dripping or leaking from the connections under the sink. What should I check first?

Leaks commonly occur if the supply line connections or mounting nuts aren't sufficiently tight. First, gently but firmly tighten all supply line nuts and mounting nuts under the sink with your wrenches, being careful not to overtighten and strip threads. If the leak persists, turn off the water, disassemble the connections, ensure all washers and O-rings are correctly seated, and reapply plumber's putty if applicable before re-tightening.

Is plumber's putty absolutely necessary, or can I use silicone caulk for sealing the new faucet to the sink?

Plumber's putty (like Oatey 311662) is the traditional choice for sealing the faucet base against the sink, creating a watertight seal that allows for easier removal in the future. Silicone caulk can also be used but creates a more permanent bond, making future faucet removal more challenging. Always check your new faucet's manufacturer instructions, as they may specify a preferred sealant or prohibit putty for certain sink materials.

Transcript
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Sometimes they can get a little complicated, but in this situation here, you can see that you've got your p-trap, which goes to an extension, which goes to the drain.

Auto-generated transcript. May contain errors.