How to Unclog a Slow Draining Bathtub

Why Is My Bathtub Draining Slowly?

A slow draining bathtub is a partial clog — water can still pass through, but the pipe is narrowed by buildup. The most common causes are:

• Hair: The #1 cause. Hair accumulates on the drain stopper, the overflow linkage, and inside the pipe, combining with soap scum to restrict water flow
• Soap scum: Bar soap leaves a waxy residue that coats pipe walls and binds with hair
• Bath products: Bath oils, bath bombs, and thick conditioners leave residue over time
• Mineral deposits: Hard water causes calcium buildup that narrows the drain

The key difference with bathtubs: the stopper mechanism and overflow linkage are unique to bathtubs and are the most commonly overlooked location for hair accumulation. Cleaning these two components fixes the majority of slow bathtub drains.

Method 1: Clean the Stopper and Overflow Linkage (Start Here)

This is the most important and most overlooked step for slow bathtub drains. Hair accumulates on both the drain stopper and the linkage mechanism connected to the overflow plate.

Clean the Drain Stopper

Identify your stopper type and remove it:

• Toe-touch stopper: Push down to open, then unscrew the center cap counterclockwise and lift out
• Lift-and-turn stopper: Lift up and turn counterclockwise to unscrew and remove
• Pop-up stopper: Lift straight up — may come out with a rocker arm attached

Clean all hair and soap scum from the stopper thoroughly. Use an old toothbrush to scrub the stopper and the drain opening.

Clean the Overflow Linkage

This step is unique to bathtubs and is often the hidden cause of slow drainage:

1. Locate the overflow plate — the oval cover on the tub wall below the faucet
2. Unscrew the 2 screws holding the plate
3. Pull the plate out slowly — the linkage mechanism (a long metal rod or spring) will come with it
4. Clean all hair and soap scum from the linkage
5. Reinsert the linkage and screw the plate back in

Cleaning the stopper and overflow linkage restores full drainage in the majority of slow bathtub cases.

Method 2: Zip-It Tool or Hair Removal by Hand

After removing the stopper, use a Zip-It tool or gloved fingers to pull out any hair visible in the drain opening.

1. Put on rubber gloves
2. Insert a Zip-It tool into the drain as far as it will go
3. Twist and pull slowly to grab and remove hair
4. Repeat until no more hair comes out
5. Flush with hot water

A Zip-It plastic drain cleaning tool ($3–5) is the most effective tool for this step.

Method 3: Baking Soda and Vinegar

After removing hair manually, baking soda and vinegar clears remaining soap scum and organic buildup from inside the pipe.

1. Pour ½ cup of baking soda directly down the drain
2. Follow immediately with ½ cup of white vinegar
3. Cover the drain with the stopper to direct fizzing downward
4. Wait 20–30 minutes
5. Flush with the hottest tap water for 2 minutes
6. Repeat if drainage is still slow

Use monthly as a maintenance treatment to prevent soap scum buildup.

Method 4: Plunger

For slow drains that don't fully clear with the above methods, a plunger creates pressure to dislodge deeper buildup.

1. Block the overflow drain: Cover the oval overflow plate opening tightly with a wet cloth — this is essential for building proper pressure in a bathtub
2. Fill the tub with 3–4 inches of water
3. Place a cup plunger over the drain, creating a complete seal
4. Plunge vigorously 15–20 times, then pull up sharply
5. Run hot water to flush loosened debris
6. Repeat 2–3 times if needed

Method 5: Drain Snake

For slow drains that don't respond to plunging, a drain snake physically reaches and removes deeper buildup.

1. Remove the drain stopper
2. Insert the snake end into the drain
3. Turn the handle clockwise while pushing forward
4. When you feel resistance, rotate to break up or hook the buildup
5. Pull back slowly, removing debris
6. Flush with hot water

Alternative: Insert the snake through the overflow plate opening (after removing the plate) to reach buildup in the overflow pipe.

Which Method to Try First

1. Start here: Clean the stopper and overflow linkage — fixes most slow bathtub drains immediately
2. If still slow: Use a Zip-It tool to remove hair from inside the drain
3. If still slow: Baking soda and vinegar to clear soap scum
4. If still slow: Plunger (with overflow blocked)
5. If still slow: Drain snake
6. If still slow: Call a plumber

Signs Your Slow Drain Is Getting Worse

• Water pools above your ankles during a bath
• Drainage takes more than 5 minutes after the tub empties
• Gurgling sounds when the tub drains
• Odors coming from the drain

Fix a slow drain before it becomes a complete blockage — it's much easier at the slow stage.

How to Prevent Slow Bathtub Drains

• Install a hair catcher: Place over the drain to catch hair before it enters the pipe. Empty after every bath or shower. The single most effective prevention tool
• Clean the stopper and overflow linkage monthly: Remove and clean both components every 3–4 weeks before buildup causes slow drainage
• Monthly baking soda and vinegar treatment: Prevents soap scum buildup inside the pipe
• Avoid bath oils in large quantities: They coat pipe walls and contribute to buildup
• Run hot water after bathing: Helps flush soap residue through the pipe

When to Call a Plumber

• Multiple drains are slow simultaneously
• Gurgling from other drains when the tub drains
• Sewage odors present
• Slow drain returns quickly after clearing
• Water backs up into other fixtures

Final Thoughts

Slow bathtub drains are almost always caused by hair and soap scum in the stopper mechanism and overflow linkage. Start by removing and cleaning the stopper and overflow linkage — this fixes most slow bathtub drains immediately. A hair catcher and monthly maintenance treatment prevent most slow drains from developing in the first place.