A bathtub that keeps running usually points to a leaky stopper seal, a worn diverter, or a valve problem—use these checks to stop the flow.
When water keeps trickling from the spout or shower head after you shut the handle, you’re dealing with wasted water and higher bills. The good news: most causes sit right at the drain, the spout diverter, or the mixing valve. This guide shows quick ways to pinpoint the fault, pick the right fix, and know when to call a pro.
Water Keeps Running In Bathtub: Quick Checks First
Start with simple, visual checks. You can learn a lot in five minutes with a flashlight and a small towel. Work from the drain up to the valve so you don’t miss the easy wins.
Fast Triage: What You See, What It Means
Match the symptom to the likely cause. Then jump to the fix section noted in the last column.
| Symptom | Most Likely Cause | Go-To Fix Section |
|---|---|---|
| Water seeps from the drain after closing the stopper | Worn stopper gasket, misadjusted linkage, debris on the seat | Stopper & Drain Seal Fixes |
| Water dribbles from spout for minutes after shutoff | Cartridge wear in mixing valve, debris on valve seats | Mixing Valve & Cartridge Fixes |
| Water splits between spout and shower when shower is on | Diverter failure, back pressure from piping to spout | Spout Diverter Fixes |
| Water drips from shower head with tub fill selected | Diverter not sealing or valve bypass leakage | Spout Diverter Fixes |
| Handle won’t fully shut off; slight flow remains | Cartridge O-rings worn, mineral buildup, wrong stem orientation | Mixing Valve & Cartridge Fixes |
| Intermittent trickle that stops, then returns | Thermal expansion in lines or debris moving inside valve | Mixing Valve & Cartridge Fixes |
Tools And Supplies You’ll Want Nearby
Keep a #2 screwdriver, adjustable wrench, needle-nose pliers, plumber’s grease, replacement O-rings or a cartridge kit for your brand, white vinegar, a soft brush, and a small bucket. A trim puller or plastic putty knife helps lift plates without marring the finish. If your spout uses a set-screw, grab a 3/32″ or 5/32″ hex key.
Stopper & Drain Seal Fixes
If water pools, then slowly drops, the drain isn’t sealing. Fixes differ by stopper style:
Identify Your Stopper
- Lift-and-turn: The cap twists to open/close; a small set-screw holds the post.
- Push-pull: Looks like lift-and-turn but you push to close, pull to open.
- Toe-touch: Press with your foot; spring inside the body.
- Trip-lever (waste-and-overflow): Lever at the overflow plate; a linkage and plunger seal the drain below the tee.
Seal Tune-Up Steps
- Clear the seating surface. Remove hair and grit at the drain rim. A soft brush and a splash of vinegar help with mineral crust.
- Inspect the gasket. Lift the stopper. If the rubber is flat, cracked, or misshapen, replace it. Match diameter and thickness.
- Adjust the height. On lift-and-turn and push-pull styles, rotate the post or collar to set the stopper slightly proud when open and fully pressed when closed.
- Trip-lever linkage: Remove the overflow plate, pull the linkage, and check the brass plunger. Clean, then set the screw so the plunger seats firmly without binding.
- Grease light contact points. A dab of plumber’s grease on threads and the pivot reduces sticking.
If the drain still seeps after new rubber and a proper adjustment, the seat may be pitted. A replacement drain body is the lasting fix. That job calls for a drain wrench and fresh putty.
Spout Diverter Fixes
When the shower is running and water still pours from the spout, or when the spout trickles long after shutoff, the diverter inside the spout may be worn. In many tubs, the diverter is part of the spout and swaps out as a kit.
How To Check The Diverter
- Feel the pull or lift. The knob should move smoothly and stay in place without springing back.
- Inspect the spout type. A slip-fit spout has a set-screw underneath; a threaded spout turns off the pipe. Turn off the water, then remove the spout and check the diverter flap or piston.
- Look for wear. Torn rubber, a weak spring, or a nicked seat will leak by and send water the wrong way.
Repair Or Replace
Some models accept a rebuild kit; others get a whole-spout swap. Brand guides spell out the steps and torque notes for their parts. If the piping from valve to spout isn’t the right size or material, back pressure can also cause split-flow at the spout and head; brand tech pages call this out with clear pipe sizing notes.
Tip That Saves Time
Before you buy parts, check the model number under the trim plate or on old paperwork. That ensures the right kit on the first run to the store.
Mixing Valve & Cartridge Fixes
Steady drips after shutoff often come from the cartridge inside the mixing body. Sand, solder flecks, or worn seals keep water sneaking past. A careful clean or a new cartridge cures most cases.
Safe Shutoff And Prep
- Kill the water. Close the bathroom stop valves or the main. Open the tub to relieve pressure.
- Remove trim. Pop the index cap, back out the screw, and pull the handle and escutcheon. Snap a photo to note parts order.
- Extract the cartridge. Some brands use a U-clip; others use screws. Rock gently, then pull straight out.
Clean Or Replace
- Clean: Rinse the cartridge, soak in warm vinegar to lift scale, then grease the O-rings. Flush the valve body for a few seconds to eject grit.
- Replace: Match the exact part number. Grease new O-rings lightly, seat the cartridge with alignment tabs set, and reinstall the clip or screws.
Final Setups
- Temp limit stop: After reassembly, test the stop ring so the hottest mix stays safe.
- Flow check: Run the tub and shower. Any cross-flow or drip? Re-seat the cartridge and verify the clip is fully home.
Confirm The Fix With A Simple Bucket Test
Fill a small container from the spout for 30 seconds, then repeat from the shower head. Compare before-and-after. A big change confirms the fix. If the drip returns within hours, debris may still be moving around; a second flush can finish the job.
When Piping Behind The Wall Causes Trouble
Some setups run plastic tubing between the valve and the spout. Warm water can make that line expand and create back pressure. The telltale sign: water comes from both spout and shower at once or the flow lags when you open the handle. The cure is a short, straight, properly sized line from valve to spout with the right material. If you see that symptom along with a newer remodel, bring in a licensed plumber to correct the run.
Water Waste Adds Up Fast
Even a small trickle can waste thousands of gallons over a year. The EPA WaterSense leak guidance shows how small leaks add to bills and offers simple checks that catch them early. Fixing this tub drip now saves water and money across your home.
Brand Notes That Matter
Brand-specific guidance can point to causes like back pressure, small but allowed drips, or diverter quirks. For one well-known line, tech pages describe how the bath spout run and materials affect performance and list small drips that can be considered normal under certain conditions. If your setup matches those notes, a piping tweak or a diverter refresh often solves split-flow or lingering drips. Many brands also publish step-by-step PDFs for their diverter or column kits, with clear drawings and part numbers.
DIY Or Pro: How To Decide
Stopper gaskets and spout swaps sit in easy DIY territory. Cartridges land in the middle: very doable with the right part and a calm approach. Re-piping between valve and spout, stuck stems, corroded screws, or unknown brands point toward a pro. Use the table below to size up the job.
| Repair | Typical Parts Cost | DIY Time Window |
|---|---|---|
| Replace stopper gasket / adjust linkage | $3–$15 | 15–30 minutes |
| Swap toe-touch or push-pull stopper | $12–$35 | 20–40 minutes |
| Replace spout with pull-up diverter | $25–$90 | 20–45 minutes |
| Install diverter rebuild kit (brand specific) | $20–$60 | 30–60 minutes |
| Replace tub/shower cartridge | $30–$180 | 30–75 minutes |
| Re-pipe valve-to-spout run | $10–$40 in fittings | 1–2 hours (often pro) |
Step-By-Step: Common Fix Paths
Path A — Seal The Drain
- Close the stopper and fill the tub to the first notch. Mark the water line with a strip of tape.
- Wait five minutes. If the level drops, pull the stopper and inspect the rubber. Replace if worn.
- Clean the seat. If pitted, plan on a new drain body. Wrap the new body in putty and tighten snugly, not brutishly.
Path B — Refresh The Diverter
- Shut water. Remove the spout (set-screw or unthread).
- Check the diverter flap or piston. If torn or weak, install a kit or swap the spout.
- Re-seat with fresh tape on threads or a clean copper stub on slip-fit. Align straight; no wobble.
Path C — Service The Mixing Body
- Shut water and pull the trim.
- Extract the cartridge. Flush the body for five seconds to clear grit.
- Install the cleaned or new cartridge. Set the temp stop and test both outlets.
Stop The Drip, Keep It That Way
- Flush lines after work. Any solder flakes or grit left in the body will haunt you with a fresh drip.
- Keep mineral crust in check. A brief soak of aerators and shower heads in warm vinegar keeps parts moving freely.
- Log the model and part number. Snap a photo and save it in your notes app. Replacements get easier next time.
- Watch for soft handle feel. A spongy handle often hints at O-rings wearing down.
When To Call A Licensed Plumber
Bring in a pro if the shutoffs won’t close, the trim hides unknown brand parts, the valve body is stuck in the wall, or the spout piping needs a new run. Tiled surrounds raise the stakes; a pro can pull trim, service the core, and button it up cleanly.
What To Tell The Parts Desk
Have these ready: brand and model (photo of the valve body helps), finish color, thread type for the spout (IPS or slip-fit), and your cartridge part number. If you can’t find the model, a clear photo of the old cartridge next to a ruler often lets the counter match it fast.
Proof You Fixed It
Run three hot-to-cold cycles. No drips for at least five minutes after shutoff. No split-flow when the shower runs. Even temperature across the range. Smooth handle travel. If all boxes are checked, you’re done.
Helpful References For Deeper Detail
The brand valve drip page explains what a small, permitted drip can look like and lists debris-related causes. Pair that with the EPA WaterSense leak page to see why quick fixes save water across the home.
Bottom Line Fix Plan
- Test the drain seal and replace worn gaskets.
- Check the spout diverter and swap the spout or kit if it leaks by.
- Service the mixing valve with a clean or new cartridge.
- Correct any short or undersized run from valve to spout if split-flow persists.