Why would a drain be slow but not fully clogged?

Hair, grease, soap, or food particles build up gradually and restrict flow. A partial clog lets some water through but slows drainage. Removing the pop-up, snaking, or cleaning the P-trap usually clears it.

Can I fix a slow drain myself?

Yes. Remove the pop-up or strainer and pull out visible debris. Use a hand-crank drain snake to break through partial clogs. For sinks, clean the P-trap. Avoid harsh chemical drain cleaners—they can damage pipes.

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Fix a drain that is slow

We'll remove the pop-up, snake the drain, and clean the P-trap to clear hair, grease, or partial clogs—or tell you when to call a plumber.

Category: Troubleshooting · Home plumbing
Time: 15–30 min
Last reviewed: Mar 6, 2026

What you'll need

Flathead screwdriver
Needle-nose pliers
Drain snake (hand-crank)
Bucket, towels, channel-lock pliers (for P-trap)
Baking soda and white vinegar (optional)

Quick triage — pick your path

Get started

Choose the option that matches what you see. You can jump straight to that section.

Follow this guide Work through the full procedure from removing the pop-up to cleaning the P-trap.
Remove pop-up and visible debris You want to clear the opening first.
Snake the drain The pop-up is clear but the drain is still slow.
Clean the P-trap The clog may be in the U-shaped pipe under the sink.
When to call a plumber The snake hits a hard stop or water backs up from multiple fixtures.

Show full guide

Steps

Goal: Confirm the drain is slow, then clear hair, grease, or partial clogs.

Run water at full volume for 30 seconds. Check that water drains slowly or pools instead of flowing freely.
Good: Water drains slowly—partial clog. Proceed to Remove pop-up and debris.
Bad: Water does not drain at all—fully clogged. See How to unclog a drain.

Remove pop-up and debris

Goal: Clear the opening by removing the pop-up or strainer and pulling out visible hair or debris.

Unscrew or pry up the drain cover with a flathead screwdriver. For pop-up stoppers, twist counterclockwise and lift out, or unhook the linkage from below.
When the cover is off, look for hair or debris at the opening. Pull it out with needle-nose pliers.
Run water and check if flow improves.
Good: Flow improves. Proceed to Verification.
Bad: Still slow—proceed to Snake the drain.

Hot water and baking soda

Goal: Loosen grease and soap buildup before snaking.

Pour very hot tap water into the drain in two or three stages. For metal pipes, boiling water is fine. For PVC pipes, use very hot tap water only—do not use boiling.
Or pour half a cup of baking soda into the drain, then half a cup of white vinegar. Cover with a wet cloth, wait 15–20 minutes, flush with hot water.
Good: Flow improves. Proceed to Verification.
Bad: No change—proceed to Snake the drain.

Snake the drain

Goal: Break through partial clogs deeper in the pipe with a drain snake.

Feed a hand-crank drain snake into the opening until you feel resistance. Crank the handle clockwise to bore through or hook the clog.
When the snake moves freely, pull it back slowly. If you find debris on the tip, you reached the blockage. Run water and verify the drain flows at full speed.
Good: Drain flows at full speed. Proceed to Verification.
Bad: Snake hits a hard stop—stop. That could be a pipe fitting. See When to get help.

Clean the P-trap

Goal: Clear blockages in the P-trap (the U-shaped pipe under the sink).

Place a bucket under the P-trap. Unscrew the slip nuts on both ends by hand or with channel-lock pliers.
When the trap drops free, dump its contents into the bucket. Look through the trap and pipe stubs—you should see daylight or light from the other end.
Reassemble finger-tight, then snug a quarter turn with pliers. Run water and verify the drain flows.
Good: Water drains; no drips at the slip nuts. Proceed to Verification.
Bad: Water still pools—the clog is deeper. See When to get help.

When to get help

Call a plumber if:

The drain is fully blocked and you cannot clear it with a snake or P-trap cleaning.
The snake hits a hard stop that will not budge (could be a pipe fitting or main-line blockage).
Water backs up from multiple fixtures (suggests main-line blockage).
You smell sewage (possible main-line or vent issue).

For other plumbing fixes, see Fix a leaking faucet or Fix a toilet that runs.

Verification

Run water at full volume for 60 seconds. Water should drain without pooling.
Check for drips at the P-trap connections (under the sink).
Confirm the drain flows at normal speed. Repeat the flow test after 24 hours to confirm the clog has not reformed.

Escalation ladder

Work from the device outward. Stop when the problem is fixed.

Confirm symptom Verify the drain is slow but not fully blocked.
Remove pop-up and debris Pull out hair and debris at the opening.
Hot water and baking soda Loosen grease and soap with hot water or baking soda and vinegar.
Snake and P-trap Snake the drain or clean the P-trap.
Call a plumber Snake hits hard stop, multiple fixtures back up, or sewage smell—call a plumber.

What to capture if you need help

Before calling support or posting for help, have these ready. It speeds everything up.

Which fixture (sink, tub, shower)
Whether removing debris helped
Snake results (debris pulled out or hard stop)
P-trap condition
Steps already tried

Does water drain slowly but not fully block?

Run water for 30 seconds. If it pools or drains slowly, you have a partial clog. If it does not drain at all, the drain is fully clogged.

Run water at full volume for 30 seconds. Good: water drains slowly or pools—partial clog. Bad: water does not drain at all—fully clogged; see how-to-unclog-drain.

Yes No (fully blocked)