How to Fix a Leaky Bathroom Sink Drain?
A leaky bathroom sink drain isn’t just an annoyance—it can lead to water damage, mold growth, and wasted money on your water bill. Fortunately, fixing most leaks is a DIY-friendly project that requires minimal tools and time. In this guide, we’ll walk you through the process of diagnosing and repairing a leaky drain, whether the issue is at the flange, P-trap, or connections. Let’s get started!
Tools and Materials You’ll Need
Before diving in, gather these supplies:
- Adjustable pliers or pipe wrench
- Screwdriver (flathead or Phillips, depending on your drain)
- Plumber’s putty or silicone caulk
- Replacement washers/gaskets (check your drain model)
- Bucket or towel (to catch water)
- Rag or sponge
- Teflon tape (for threaded connections)
- Flashlight (to inspect under the sink)
Step 1: Turn Off the Water Supply
Locate the shut-off valves under the sink and turn them clockwise to stop water flow. If there are no valves, shut off the main water supply to your home.
Step 2: Identify the Source of the Leak
Dry the area under the sink with a towel, then run water briefly to pinpoint where the leak originates:
- Drain Flange: Leaks around the sink basin.
- P-Trap or Slip Nuts: Dripping from the curved pipe under the sink.
- Pop-Up Assembly: Leaks near the lever or behind the drain.
Step 3: Fix a Leaky Drain Flange
Problem: Water seeping around the drain opening in the sink.
- Remove the Drain Flange:
- Unscrew the retaining nut under the sink holding the drain pipe to the basin. Use pliers if needed.
- Push the drain pipe down and twist the flange counterclockwise to remove it.
- Replace the Plumber’s Putty:
- Scrape off old putty or caulk from the flange and sink hole.
- Roll a new plumber’s putty into a rope and apply it around the flange’s underside.
- Reinsert the flange, tighten the nut underneath, and wipe away excess putty.
Step 4: Repair Leaks at the P-Trap
Problem: Drips from the U-shaped pipe (P-trap).
- Loosen the Slip Nuts:
- Place a bucket under the P-trap. Use pliers to loosen the nuts connecting it to the tailpiece and wall pipe.
- Inspect and Replace Parts:
- Check the P-trap for cracks (replace if damaged).
- Swap worn rubber washers or slip nuts. Apply Teflon tape to threaded connections for a tighter seal.
- Reassemble the P-Trap:
- Hand-tighten the nuts first, then give a quarter-turn with pliers (avoid overtightening).
Step 5: Address Pop-Up Assembly Leaks
Problem: Leaks near the drain’s lever or behind the stopper.
- Remove the Pop-Up Mechanism:
- Detach the lift rod from under the sink by unscrewing the retaining clip.
- Unscrew the pivot nut and pull out the assembly.
- Replace Gaskets:
- Inspect the rubber gasket at the base of the assembly. Replace if cracked or flattened.
- Reinstall the pop-up, ensuring all connections are snug.
Step 6: Test for Leaks
Turn the water supply back on and run the sink. Check for drips. If leaks persist, tighten connections slightly or revisit steps to ensure all seals are properly installed.
Troubleshooting Tips
- Persistent Leaks: Double-check for hairline cracks in pipes or misaligned washers.
- Stubborn Connections: Soak nuts in vinegar to dissolve mineral deposits before loosening.
- Wrong Parts?: Bring old washers/gaskets to the hardware store to match replacements.
When to Call a Professional
If leaks continue after troubleshooting or you spot significant corrosion/pipe damage, contact a licensed plumber. Complex issues like soldering pipes or replacing wall connections may require expert help.
Prevent Future Leaks
- Avoid overtightening connections to prevent cracks.
- Clean drains monthly to prevent clogs and corrosion.
- Replace rubber washers every few years as part of routine maintenance.
Final Thoughts
Fixing a leaky bathroom sink drain is a simple yet satisfying DIY task. With the right tools and patience, you can save money and protect your home from water damage. Remember: Take your time, follow each step carefully, and don’t hesitate to ask for help if the job gets tricky. Happy fixing!
