How to Clean Bathtub Overflow Drain

The bathtub overflow drain — that small opening near the top of the tub, usually covered by a decorative plate — is one of the most overlooked cleaning spots in the bathroom. It prevents the tub from overflowing, but it also collects soap scum, mold, hair, and mineral deposits that cause odors and reduce its effectiveness. Here's how to clean it properly.

What Is the Overflow Drain?

The overflow drain is a secondary drain located on the front wall of the bathtub, several inches below the rim. It's connected to the main drain pipe and activates when water rises too high, preventing flooding. It's covered by an overflow plate (usually oval or round) that may also house the trip lever for a stopper mechanism.

Why the Overflow Drain Gets Dirty

Soap scum and mineral deposits accumulate on the plate and inside the opening
Hair gets sucked into the overflow opening during bathing
Mold and mildew grow in the damp, dark interior
The interior pipe collects debris that causes odors

What You'll Need

Screwdriver (Phillips or flathead)
White vinegar
Baking soda
Small brush or old toothbrush
Flexible cleaning brush
Rubber gloves
Microfiber cloth

Step-by-Step: How to Clean the Overflow Drain

Step 1: Remove the Overflow Plate

Locate the screws on the overflow plate (usually 2 screws).
Unscrew with a Phillips or flathead screwdriver and set aside.
Carefully pull the plate away from the wall. If it has a trip lever mechanism, the linkage assembly will come with it — note how it's assembled before removing.

Step 2: Clean the Overflow Plate

Soak the plate in undiluted white vinegar for 20–30 minutes.
Scrub with a small brush, paying attention to the decorative grooves and the back of the plate.
For stubborn mineral deposits, apply a baking soda paste and scrub.
Rinse thoroughly and dry.

Step 3: Clean the Overflow Opening

Use a flexible cleaning brush to reach inside the overflow opening and scrub the interior walls.
Remove any hair or debris you encounter.
Spray white vinegar into the opening and let sit for 10 minutes.

Step 4: Flush the Overflow Pipe

Pour ½ cup of baking soda into the overflow opening.
Follow with 1 cup of white vinegar.
Let the fizzing reaction work for 15 minutes.
Pour a cup of hot water into the opening to flush.

Step 5: Clean the Trip Lever (If Applicable)

If your overflow plate has a trip lever stopper mechanism:

Soak the entire linkage assembly in white vinegar for 30 minutes.
Scrub with a small brush to remove mineral deposits and soap scum.
Rinse and dry before reinstalling.

Step 6: Reinstall the Overflow Plate

If you removed a trip lever assembly, reinsert it into the overflow pipe first, ensuring the linkage is correctly oriented.
Align the plate over the opening and screw back into place.
Don't overtighten — snug is sufficient.
Test the stopper function if applicable.

Cleaning the Overflow Drain Without Removing the Plate

For a quick clean without full disassembly:

Spray white vinegar around and into the overflow opening.
Use a small brush to scrub the plate surface and around the opening edges.
Pour baking soda followed by vinegar into the opening for a pipe flush.
Wipe the plate with a vinegar-dampened microfiber cloth.

How Often Should You Clean the Overflow Drain?

Surface wipe of the plate: weekly with regular tub cleaning
Baking soda + vinegar pipe flush: monthly
Full removal and deep clean: every 3–6 months

Frequently Asked Questions

Why does my overflow drain smell?

Odor from the overflow drain is caused by hair, soap scum, and bacteria inside the pipe. A baking soda and vinegar flush followed by hot water usually eliminates the smell. For persistent odor, a diluted bleach flush (let sit 10 minutes, flush with cold water) is effective.

Can I use the overflow drain to unclog the main drain?

Yes — if you block the overflow drain with a wet cloth while plunging the main drain, you create better suction. This is a standard plunging technique for bathtub clogs.

My overflow plate screws are stripped — how do I remove it?

Try a rubber band between the screwdriver and screw head for better grip. If that fails, a screw extractor bit (available at hardware stores) can remove stripped screws.

Final Thoughts

The overflow drain is easy to overlook but important to maintain. A monthly baking soda and vinegar flush keeps the pipe clear and odor-free, while a quarterly full removal and clean ensures nothing is missed. The whole process takes under 20 minutes and prevents the odors and drainage issues that come from a neglected overflow drain.

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