Quick answer
To fix a leaky bathroom sink faucet, turn off the water supply, disassemble the faucet, inspect for worn parts like washers or O-rings, and replace them. Reassemble and test for leaks.
Confirm the symptom
- Water dripping from the faucet when off
- Low water pressure from the faucet
- Faucet handle is loose or wobbly
- Water leaks around the base of the faucet
- Faucet doesn't shut off completely
Tools and prep
- Adjustable wrench
- Screwdrivers (flathead and Phillips)
- Plumber's putty or silicone sealant
- Replacement washers, O-rings, or cartridge (if needed)
- Bucket or towel to catch water
- Turn off water supply under the sink before starting
- Wear rubber gloves to prevent cuts from sharp parts
Step-by-step troubleshooting
- Turn Off Water SupplyDo: Locate and turn off the shut-off valves under the sink. If there are no valves, turn off the main water supply.Observe: Water stops flowing from the faucet.Means: Water is safely turned off for repairs.Next: Disassemble the Faucet
- Disassemble the FaucetDo: Use a screwdriver to remove the handle and expose the internal components. Take note of the order of parts for reassembly.Observe: Internal parts like the stem, cartridge, or O-rings are visible.Means: You can now inspect and replace faulty parts.Next: Inspect for Worn Parts
- Inspect for Worn PartsDo: Look for damaged washers, O-rings, or a worn-out cartridge. These are common causes of leaks and drips.Observe: Visible wear or damage on internal components.Means: Identify which parts need replacement.Next: Replace Faulty Parts
- Replace Faulty PartsDo: Install new washers, O-rings, or a new cartridge as needed. Apply plumber's putty or sealant to ensure a watertight fit.Observe: New parts are securely in place and aligned.Means: Faulty components are replaced with new ones.Next: Reassemble the Faucet
- Reassemble the FaucetDo: Put the faucet back together in the reverse order of disassembly. Tighten all screws and connections securely.Observe: Faucet is fully reassembled with no loose parts.Means: Faucet is ready for testing.Next: Test for Leaks
- Test for LeaksDo: Turn the water supply back on and slowly open the faucet. Check for any leaks around the handle or base.Observe: No water leaks from the faucet.Means: Faucet is functioning properly after repairs.Next: Done
Common causes
| Cause | Likelihood | Difficulty | Part often needed |
|---|---|---|---|
| Worn-out washers or O-rings Over time, rubber seals degrade and can't create a tight seal, causing leaks. | Common | Easy | Washer or O-ring kit |
| Faulty cartridge A worn or damaged cartridge can cause leaks and poor water flow. | Common | Medium | Faucet cartridge |
| Loose or damaged handle A loose handle can lead to water dripping or inconsistent water flow. | Sometimes | Easy | Handle screw or replacement handle |
| Corroded valve seat Mineral buildup or corrosion on the valve seat can prevent a proper seal. | Sometimes | Medium | Valve seat wrench and replacement seat |
| Clogged aerator Mineral deposits can clog the aerator, reducing water pressure. | Sometimes | Easy | Aerator or descaling solution |
| Improper installation Incorrect assembly or overtightening can cause leaks or damage. | Rare | Easy | None |
| Pipe leaks Cracked or corroded pipes under the sink can cause water to leak around the base. | Rare | Hard | Pipe repair kit or replacement pipe |
Parts matching
Common parts needed for bathroom sink faucet repairs include:
- Washer or O-ring kit for sealing the faucet
- Faucet cartridge for cartridge-style faucets
- Handle screw or replacement handle for loose handles
- Valve seat wrench and replacement seat for corroded seats
- Aerator or descaling solution for clogged aerators
Take the old parts to the hardware store to ensure you get the correct replacements.
When to call a professional
- Leak persists after replacing all visible parts
- Water pressure issues continue after cleaning the aerator
- Faucet is old and requires full replacement
- You suspect pipe leaks under the sink
- You're unsure about the type of faucet or repair process
FAQ
How do I know if my faucet needs a new cartridge?
If your faucet leaks when off or has inconsistent water flow, a faulty cartridge is likely the cause. Disassemble the faucet to check for wear or damage.
Can I fix a leaky faucet without turning off the water?
No, always turn off the water supply before starting repairs to avoid water damage and ensure safety.
Why is my faucet handle loose?
A loose handle is often due to a worn or missing screw. Tighten or replace the screw to secure the handle.
How do I clean a clogged aerator?
Unscrew the aerator, soak it in vinegar to dissolve mineral deposits, and rinse thoroughly before reattaching it to the faucet.
What if my faucet still leaks after replacing parts?
Double-check that all parts are installed correctly and tightened properly. If the leak continues, the issue may be with the valve seat or pipes, and a professional may be needed.