How to Fix a Slow-Draining Bathtub
A slow-draining bathtub is almost always caused by hair and soap scum clogging the drain stopper, the drain crosshairs, or the P-trap below. Start by removing the drain stopper or strainer and pulling out the visible hair clog with needle-nose pliers — this fixes 60–70% of slow tub drains in under 5 minutes. If that doesn't restore full flow, use a drain snake (also called a drum auger, $20–$30) fed through the overflow plate opening to break through deeper clogs in the P-trap or branch drain. Avoid chemical drain cleaners — they damage pipes and rarely clear the compacted hair-and-soap mass that causes tub clogs. If snaking doesn't work, the clog is likely in the main branch line and needs a plumber with a power auger ($150–$300).
Cost Breakdown
| Service | Low | High | Notes |
|---|---|---|---|
| Mesh drain cover / hair catcher | $3 | $8 | Prevents most clogs; clean after every use |
| Hand-crank drain snake (drum auger) | $20 | $30 | 25-foot 1/4-inch cable; reusable for years |
| Enzyme drain maintainer (annual supply) | $8 | $12 | Monthly preventive treatment; safe for all pipe types |
| Professional drain cleaning (plumber) | $150 | $300 | Power auger service for clogs beyond DIY snaking |
| Camera inspection + line cleaning | $250 | $500 | For recurring clogs — identifies root intrusion, pipe damage, or bellied pipe |
Step 1: Remove and Clean the Stopper
The drain stopper mechanism is the first place hair collects. How to remove it depends on the type:
- Lift-and-turn stopper: Lift it to the open position, grip the knob, and turn counterclockwise to unscrew from the crosshair drain.
- Push-pull stopper: Lift the stopper up and unscrew the knob counterclockwise while holding the stopper body. Some have a set screw on the side.
- Toe-touch stopper: Open the stopper by pressing, then twist the cap counterclockwise to unscrew from the shaft.
- Trip-lever (internal plunger): Unscrew the overflow plate (two screws), then pull the entire linkage assembly and plunger out through the overflow opening. The plunger often has a massive hair accumulation.
Clean hair, soap scum, and buildup off the stopper and the drain opening. Reassemble and test — if water flows freely, you're done.
Step 2: Snake Through the Overflow Opening
- Remove the overflow plate cover (two screws above the tub drain, below the faucet).
- Feed a 1/4-inch drain snake into the overflow opening and push down. The snake will curve through the overflow tube and into the P-trap — this is where the clog usually lives.
- When you feel resistance, crank the snake handle to break through the clog. Pull the snake out and clean the debris off the cable.
- Run hot water for 2–3 minutes to flush loosened material down the drain.
Step 3: Flush with Hot Water and Dish Soap
After mechanical clearing, pour a pot of boiling water mixed with a tablespoon of dish soap down the drain. The soap helps dissolve remaining soap scum coating the pipe walls. This is maintenance, not a fix — it works to restore flow after the physical clog is removed, but won't clear a blockage on its own.
What Not to Do
- Don't use chemical drain cleaners (Drano, Liquid-Plumr): They generate heat that softens PVC pipe joints and corrodes older metal pipes. They rarely dissolve compacted hair — the active ingredients work on organic food waste, not keratin-based hair clogs. If you use one and it doesn't work, you now have a pipe full of caustic chemical that a plumber has to deal with.
- Don't use a plunger aggressively: Plunging a tub drain with a trip-lever stopper can push the linkage assembly out of alignment, creating a bigger problem. Remove the stopper mechanism first if you plunge.
Preventing Future Clogs
Install a mesh drain cover or hair catcher ($3–$8) over the drain. Clean it after every shower. This single step prevents 90% of tub drain clogs. For households with long-haired residents, monthly enzyme drain maintainer ($8–$12 for a year's supply) breaks down hair buildup before it accumulates into a clog.
Related Questions
Why does only my bathtub drain slowly while other drains work fine?
Tub drains collect more hair and soap than any other drain in the house. Each drain has its own P-trap and branch line, so a clog in the tub drain doesn't affect the sink or toilet. If multiple drains are slow simultaneously, the problem is in the main sewer line, not the individual branch.
Is baking soda and vinegar effective for a slow tub drain?
It produces a fizzing reaction that feels productive but has minimal cleaning power. The reaction produces water, CO2, and sodium acetate — none of which dissolve hair. It's marginally better than nothing for soap scum buildup but won't clear an actual clog. Use a drain snake instead.
How often should I snake my bathtub drain?
If you use a hair catcher, you shouldn't need to snake at all. Without one, long-haired households may need to snake every 6–12 months. If you're snaking more often than that, install a hair catcher and use monthly enzyme treatments.