Quick Answer:
If your sink drains slowly even when the stopper looks “open,” the stopper or its linkage is likely still restricting flow. A fast check is to remove the stopper and test drainage with it fully out of the drain. If water runs freely with the stopper removed, focus on cleaning, realigning, or replacing the stopper and pivot parts.
Why This Happens
- Debris under the stopper or around the seat (hair, soap scum) can stop water even when the top looks open.
- A bent pivot rod or misaligned linkage can leave the stopper sitting partially down.
- Worn gaskets or a warped stopper no longer seals or lifts correctly.
- Corrosion or mineral build-up around the stopper seat limits passage.
- A problem in the pop-up mechanism can also cause odd fit or slow flow; look for signs like a sticking lever or water pooling when the stopper is raised — this can point to Pop-up assembly leaking or failing parts.
Step-by-Step What to Do
Step 1 — Prepare and observe
- Clear the area under the sink and place a small bucket beneath the P-trap in case you need to loosen it.
- Operate the stopper up and down while watching from above to see if it moves freely or looks tilted.
Step 2 — Remove the stopper
Most stoppers pull straight out after you disconnect the pivot rod under the sink, or they lift out if they are a pop-up plug. Remove the stopper and test drainage with it fully out of the drain. If water drains normally without the stopper, the problem is with the stopper or its immediate parts—not a deeper sewer clog.
Step 3 — Clean the stopper and seat
- Wipe away hair, gunk and mineral deposits from the stopper and the drain seat. A soft brush or old toothbrush works well.
- For mineral deposits, soak the metal parts briefly in a vinegar and water solution, then rinse thoroughly.
Step 4 — Inspect and adjust the linkage
- Look at the pivot rod, spring clip, and lift arm under the sink. Make sure the pivot rod isn’t bent and the clip sits in the correct hole on the lever.
- Reattach the pivot rod so the stopper lifts fully and sits squarely in the opening.
Step 5 — Reinstall and test
- Put the stopper back in and operate the lift mechanism several times to confirm smooth travel and full opening.
- Run water and watch drainage. If flow is restored, the job is done.
Step 6 — If removing the stopper did not help
- Try using a hand drain snake from the sink (not a chemical) to check for clogs beyond the stopper seat.
- If a snake reaches and clears a blockage, retest with and without the stopper in place.
What Not to Do
- Do not keep using chemical drain cleaners when the stopper is restricting flow. They won’t fix a mechanical fit problem and can damage finish and seals.
- Do not jam sharp tools down the drain trying to lever debris free; you can damage the seat or stopper.
- Avoid forcing bent parts back into place; if the pivot rod or stopper is badly warped, replace it.
When to Call a Professional
- If the pivot rod or pop-up assembly is broken, corroded, or cannot be adjusted to lift the stopper properly.
- When there is a persistent clog beyond the trap that a homeowner snake can’t clear.
- If you discover leaks at the tailpiece, P-trap, or see continuous water under the sink after repairs.
- If the stopper problem started after installation work and you suspect incorrect parts or alignment — for example, when the **Stopper fails after faucet install** and you can’t restore proper function.
Safety Notes
- Wear gloves and eye protection when cleaning gunk from the stopper and drain.
- Do not mix chemical cleaners with other products; fumes and reactions are dangerous.
- Have a bucket and towels ready when disconnecting plumbing to catch spills.
- If you’re unsure about removing parts or dealing with corroded fittings, stop and call a pro to avoid breaking components.
Common Homeowner Questions
- Why does the stopper look open but water still pools? Because the stopper or linkage is not fully clearing the drain seat — debris or misalignment often keeps it partially closed.
- Can I fix this without special tools? Yes. Many stoppage and alignment issues can be handled with a screwdriver, pliers, a cloth, and a small snake for deeper clogs.
- How long before I should call a plumber? If removing and cleaning the stopper doesn’t restore normal flow, or if parts are broken or leaking, call a plumber after one or two simple attempts to fix it yourself.