Quick answer
A leaky sink faucet or pipe can often be fixed by replacing the washer or O-ring. Turn off the water supply, disassemble the faucet, and check for worn or damaged parts. Reassemble with new parts and test for leaks.
Confirm the symptom
- Water is dripping from the faucet or pipe
- Leak occurs even when the faucet is fully closed
- Moisture or puddles under the sink
Tools and prep
- Adjustable wrench
- Screwdrivers (flathead and Phillips)
- Plumber's putty or Teflon tape
- Replacement washers or O-rings
- Bucket or towel to catch water
- Turn off water supply before starting
Step-by-step troubleshooting
- Turn Off Water SupplyDo: Locate and turn off the shut-off valves under the sink.Observe: Water stops flowing from the faucet.Means: Water supply is safely cut off.Next: Disassemble the faucet
- Disassemble the FaucetDo: Use a screwdriver to remove the handle and expose the valve stem.Observe: Valve stem and internal parts are visible.Means: Access to the faulty components is gained.Next: Inspect for wear
- Inspect for WearDo: Check the washer and O-ring for cracks or wear.Observe: Worn or damaged parts are identified.Means: Leak is likely due to faulty seals.Next: Replace parts
- Replace PartsDo: Install new washer or O-ring onto the valve stem.Observe: Parts are securely in place.Means: Leak should be resolved with new seals.Next: Reassemble faucet
- Reassemble FaucetDo: Put the faucet back together and tighten all components.Observe: Faucet is fully reassembled.Means: Ready for testing.Next: Test for leaks
- Test for LeaksDo: Turn the water supply back on and check for leaks.Observe: No water drips or leaks from the faucet.Means: Repair was successful.Next: Monitor over time
Common causes
| Cause | Likelihood | Difficulty | Part often needed |
|---|---|---|---|
| Worn Washer The washer deteriorates over time and no longer creates a tight seal. | Common | Easy | Washer |
| Damaged O-Ring The O-ring can crack or become misshapen, causing a leak. | Common | Easy | O-Ring |
| Loose or Corroded Valve Seat Mineral buildup or corrosion can prevent the valve from sealing properly. | Sometimes | Easy–Medium | Valve Seat |
| Faulty Cartridge In cartridge faucets, a worn or damaged cartridge can cause leaks. | Sometimes | Medium | Cartridge |
| Pipe Leak Cracks or loose connections in the pipes under the sink can cause water to drip. | Sometimes | Medium | Pipe or Fitting |
| High Water Pressure Excessive water pressure can stress the faucet and cause leaks. | Rare | Hard | Pressure Regulator |
| Faulty Installation Improper installation of the faucet or parts can lead to leaks. | Rare | Medium | None |
Parts matching
Match your sink's issue to the right part for an effective repair:
- Worn washer or O-ring: Replace with a standard rubber or silicone seal
- Loose valve seat: Use a valve seat wrench to tighten or replace
- Damaged cartridge: Purchase a replacement cartridge matching your faucet model
- Pipe leak: Use a pipe repair kit or replace the damaged section
- High water pressure: Install a pressure regulator if pressure exceeds 60 psi
Always turn off the water supply before replacing any parts to avoid water damage.
When to call a professional
- The leak persists after replacing all visible parts
- You notice water damage or mold under the sink
- The pipes are corroded or cracked beyond simple repair
- You are unsure about the faucet type or model
- The water pressure issue requires a professional pressure test
FAQ
Can I fix a leaky faucet without turning off the water?
No, always turn off the water supply to avoid water damage and ensure safety during repairs.
How often should I replace washers and O-rings in my faucet?
Inspect and replace washers and O-rings every 1–2 years, or when you notice leaks.
Why is my faucet leaking even after replacing the washer?
The valve seat might be damaged, or the O-ring could be improperly seated. Check both for wear or misalignment.
What type of wrench should I use for faucet repairs?
An adjustable wrench or basin wrench is best for faucet repairs to avoid damaging the finish.
Can a leaky faucet increase my water bill?
Yes, a continuous leak can waste hundreds of gallons of water per day, leading to higher bills.