How to Install a New Bathroom Faucet: A Weekend DIY Project

Replacing an old or outdated bathroom faucet is a relatively simple DIY project that can dramatically improve the look and functionality of your bathroom. With basic tools and a few hours of time, you can install a new faucet and save on plumbing service costs. This guide walks you through the process step by step.

Tools and Materials You’ll Need

• New bathroom faucet kit
• Adjustable wrench
• Basin wrench or channel-lock pliers
• Bucket or small container
• Towels or rags
• Plumber’s putty or silicone caulk
• Teflon tape
• Flashlight
• Safety glasses
• Penetrating oil (like WD-40) for stubborn nuts

Before You Begin

1. Purchase the right faucet: Ensure your new faucet matches your sink’s hole configuration (single-hole, 4″ centerset, or 8″ widespread)
2. Turn off the water: Locate the water shut-off valves under the sink and turn them clockwise to shut off both hot and cold water
3. Open the faucet: Turn on the faucet to release pressure and drain remaining water
4. Clear space: Remove items from under the sink to give yourself room to work

Step 1: Remove the Old Faucet

1. Place a bucket under the water lines to catch any remaining water
2. Disconnect the water supply lines from the faucet by unscrewing the nuts connecting them (use the adjustable wrench)
3. Locate the mounting nuts that secure the faucet to the sink – these are usually located underneath the sink and might require a basin wrench to reach
4. Unscrew and remove these mounting nuts
5. Lift the old faucet from above the sink – you may need to wiggle it a bit if caulk or mineral deposits are holding it in place
6. Clean the sink surface thoroughly, removing any old putty, caulk, or debris

Step 2: Prepare the New Faucet

1. Unpack your new faucet and review the manufacturer’s instructions
2. Assemble any parts that need to be attached to the faucet before installation (this varies by model)
3. If your faucet uses a gasket, attach it to the bottom of the faucet base
4. If your faucet requires plumber’s putty instead of a gasket:
   • Roll a small amount of plumber’s putty between your hands to form a thin “rope”
   • Apply it in a circle around the base of the faucet where it will contact the sink

Step 3: Install the New Faucet

1. Feed the faucet’s supply lines and mounting hardware through the holes in the sink
2. Position the faucet so it’s straight and centered
3. From underneath, secure the faucet by screwing on the mounting nuts – tighten by hand first, then use a wrench for the final tightening, but be careful not to overtighten
4. Wipe away any excess putty that squeezed out from under the faucet

Step 4: Connect the Water Supply Lines

1. Wrap the threaded ends of the water supply lines with 2-3 turns of Teflon tape (wrap clockwise in the direction of the threading)
2. Connect the supply lines to the shut-off valves (hot to hot, cold to cold)
   • Hand-tighten first
   • Then give an additional quarter to half turn with a wrench
   • Be careful not to overtighten, which can damage the fittings

Step 5: Install the Drain Assembly (if included)

Many new faucets come with a matching drain assembly. If yours does:

1. Remove the old drain by unscrewing the P-trap and the mounting nut connecting the drain to the sink
2. Apply plumber’s putty under the flange of the new drain
3. Insert the new drain assembly from above the sink
4. From below, attach and tighten the gasket, washer, and mounting nut
5. Reconnect the P-trap to the new drain tail piece

Step 6: Test for Leaks

1. Turn the water supply back on by turning the shut-off valves counterclockwise
2. Turn on the faucet and check for leaks:
   • Check all connections – under the sink, around the base of the faucet, and at the drain
   • Look for any dripping or moisture
   • If you find leaks, turn off the water and tighten the connections slightly
3. Run both hot and cold water to ensure proper operation
4. Test the drain by filling the sink and then draining it while checking for leaks

Troubleshooting Common Issues

• Leaking from connection points: Usually requires tightening or reapplying Teflon tape
• Leaking from faucet base: May need more plumber’s putty or tightening of mounting nuts
• Low water pressure: Check if aerator is clogged or supply valves aren’t fully open
• Handles not aligned: Most handles can be removed and repositioned without affecting function

When to Call a Professional

While faucet installation is generally DIY-friendly, consider calling Wade’s Plumbing & Septic if:

• You discover corroded or damaged pipes that need replacement
• You need to modify your plumbing to accommodate the new faucet
• You encounter persistent leaks that you can’t resolve
• Your home has complex plumbing or non-standard installations

Installing a new bathroom faucet is a satisfying DIY project that most homeowners can complete in 2-3 hours. With proper installation, your new faucet should provide years of reliable service while enhancing your bathroom’s appearance.