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Disconnect Plumbing Lines — Disconnect the Faucet Supply Lines

Beginner3 hours

Part of project

How to Replace a Bathroom Faucet: A Step-by-Step DIY Guide · Step 2 of 6

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In this video

Using an adjustable wrench, carefully loosen and unscrew the nuts that connect the water supply lines to the shut-off valves. Have a small container ready to catch any water that drains out. Next, locate the slip nuts on the P-trap drain pipe and loosen them, either by hand or with channel-lock pliers. Remove the P-trap and set it aside.

Goal: Disconnect supply lines and P-trap

  • Be gentle when loosening the connections to avoid damaging the pipes or valves.

Used in this video

  • Adjustable Wrench — Loosening the nuts on the water supply lines.
  • Pliers (Pliers_Type: Channel-Lock) · optional — Loosening stubborn slip nuts on the P-trap.
  • Container for Parts (Container Type: Bucket) — Catching residual water from the pipes.
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FAQs

Why is a basin wrench listed as a required tool for this project?

A basin wrench is crucial because it's specifically designed to reach and loosen the mounting nuts that secure the faucet from underneath the sink. These nuts are often in very tight, awkward spaces where a regular adjustable wrench simply cannot fit or get enough leverage.

What should I do if the old faucet's mounting nuts are corroded and won't budge?

First, try applying a penetrating oil to the corroded nuts and let it sit for 15-30 minutes to help break down the rust. If they still won't turn, you may need to use a small hacksaw or a specialized nut splitter designed for plumbing to carefully cut through the nuts. Always wear eye protection when doing this.

Is 3 hours a realistic time estimate for someone who's never replaced a faucet before?

While 3 hours is a good estimate for an experienced DIYer, beginners should budget a bit more time, perhaps 4-6 hours. This allows for unexpected challenges like stubborn old parts, cleaning time, and carefully familiarizing yourself with the new faucet's instructions without rushing.

After installing the new faucet and turning the water back on, I have a small leak under the sink. What should I check first?

The most common culprits for leaks are loose supply line connections or improperly tightened mounting nuts. Gently but firmly tighten these connections with your adjustable wrench. If the leak persists, you may need to disassemble the connection, inspect the washers/gaskets, and reassemble with plumber's tape or a fresh application of plumber's putty if applicable.

Transcript
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Turn the faucet knob to release any excess water. Use the adjustable wrench to unscrew the fastener so you can disconnect the supply lines. Be very careful not to break any connections. Be slowly to the direction of the container so that any excess water will go into that container. Repeat the same process on the other side of the supply connection. Then drain the excess water into the container so that you won't have any spillage on the floor. Then you may now unhook the drain pipe by loosening up the tab that holds them together as shown in this video.

Auto-generated transcript. May contain errors.