Start with the type of valve you have
Look at the handles. Two handles, one hot and one cold, usually mean a compression or ceramic disc valve. One handle that pushes in and out and turns for temperature is a cartridge or ball valve. A knob that pulls up for the shower is the diverter, and it can leak into the tub spout even if the main valve is fine.
Remove the handle cap and take a photo of the parts before you touch anything. The brand name on the trim, often stamped on the escutcheon or inside the cartridge, helps you buy the right replacement. Take the old cartridge to the store to match it.
Symptoms, causes, and the right next move
Use this table to separate a quick repair from a call.
| Symptom | Likely cause | Fix | DIY? |
|---|---|---|---|
| Drip from the spout, handle off | Worn washer, seat, or cartridge | Replace the part | Yes |
| Water at the handle base | Worn O-ring or loose packing | Replace the O-ring | Yes |
| Water runs from the tub spout when shower is on | Failed diverter | Replace the diverter or the spout | Often |
| Hot and cold mix when the handle is off | Cartridge or check stop failure | Replace the cartridge | Sometimes |
| Stain or drip on the ceiling below | Leak in the valve body or supply | Open the wall and repair | Call |
| Handle will not shut water off | Damaged seat or valve body | Replace the valve | Call |
A valve body inside the wall usually requires access from the other side of the wall.
Swapping a leaking cartridge
- 1
Shut off the water.
Close the bathroom shutoff or the main, then open the faucet to drain the line.
- 2
Pull the handle and trim.
Take off the cap, remove the screw, slide off the handle, and unscrew the trim plate.
- 3
Remove the cartridge.
Pull out the retaining clip or nut, then lift or twist the cartridge out. Some need a puller tool.
- 4
Install the match and reassemble.
Seat the new cartridge in the same orientation, secure it, replace the trim, and turn the water on slowly.
What to do if you cannot shut the water off
A tub faucet whose stops do not work turns a small job into a bigger one.
- Close the main water valve.
It is usually near the water meter or where the line enters the house. Know where yours is.
- Check for fixture stops.
Some homes have small shutoff screws behind an access panel in the next room. Not all do.
- Do not force a stuck handle.
Cranking it can break the stem inside the wall.
- Place a bucket and towel.
A slow flow is manageable, but stop if it grows.
- Call a plumber.
If the main valve will not close either, treat it as an emergency.
Signs the leak is inside the wall
A brown stain on the ceiling under the bathroom, bubbling paint, a musty smell, or a floor that feels soft beside the tub all point to hidden water. Dripping at the spout alone does not cause those signs. Stop using the tub, photograph the damage, and call, because wet framing and drywall get worse with every shower.
Wildwood homes and tub faucets: what to know locally
The US Census Bureau's 2020-2024 American Community Survey counts 5,087 Wildwood homes built from 1990 to 1999 and 3,677 built from 1980 to 1989, out of 13,391 housing units. Tub valves from those decades have seen many years of daily use, so a worn cartridge is a common finding. If yours is original, plan on replacing it rather than patching it.
Missouri American Water supplies Wildwood, per the city's FAQ. Its 2023 St. Louis region report prints total hardness from 66 to 226 ppm as CaCO3 depending on the plant, and which plant serves your address is not stated. Minerals leave scale on cartridges and seats, so ask your plumber whether a softer-water fix or a different cartridge makes sense after you test your tap.
The City of Wildwood's building permits page lists minor repairs among work that does not need a building permit, and new or replaced plumbing among work that does. A cartridge swap sits on the minor side, while replacing a valve in the wall is a different job, so ask the building department when unsure.
Sources: US Census ACS 2020-2024, Missouri American Water 2023 water quality report, City of Wildwood FAQ, City of Wildwood building permits page
Why a quick fix sometimes fails twice
A new cartridge in a pitted valve body can still leak, because the housing is scored. Reusing a worn seat under a new washer is the same trap. If the same drip returns within weeks, the valve itself is the problem.
Over-tightening also causes trouble. Cranking a trim screw can crack a plastic cartridge, and a wrench on a brass nut can distort the seat. Snug is enough, and thread tape is only for tapered pipe threads, not the cartridge.
When to hand it to a plumber
Our faucet repair team replaces cartridges, diverters, and valves, and our leak detection service finds the source when the stain does not match the faucet. For a wall leak or a valve that will not shut, call our 24/7 line and we will schedule a same-day visit when available.
Homeowners in Ballwin and Ellisville have older bathrooms on average, and the cartridge swap is the same. Check with your own city's building office if you plan to replace the valve behind the wall.
Tub faucet will not shut off?
Close the main valve and call, so a drip does not become a soaked wall.
Questions we hear in Wildwood, MO
A worn washer, seat, or cartridge is the usual cause. Shut off the water, identify your valve type, and replace the worn part. If a new part does not stop the drip, the valve body may be scored.
Yes, in most homes a careful homeowner can do it in under an hour. Shut off the water, photograph the parts, and take the old cartridge to match it. Stop and call if the handle is seized or the shutoff will not work.
A ceiling stain below the bathroom, bubbling paint, a musty smell, or a soft floor near the tub are the signs. A drip from the spout alone does not cause them. Stop using the tub and call a plumber.
The diverter is not sealing. Some diverters are on the spout and can be replaced by unscrewing the spout, and others are in the valve. If you see a steady stream instead of a small leak, replace the diverter.
The 2020-2024 American Community Survey shows 5,087 Wildwood homes built from 1990 to 1999, so many tub valves have decades of use. We cannot name the brand in your wall without looking, and the fix depends on the valve type. Photograph the trim and call with the details.
If only the tub is weak, scale in the cartridge or diverter is likely. If every fixture is weak, call Missouri American Water using the customer service number in its water quality report, since the city does not manage utility records. A plumber can then check pressure inside your home.
The city's permits page lists minor repairs as work that does not need a building permit and new or replaced plumbing as work that does. A cartridge swap is minor, but replacing a valve in the wall is not. Permit rules vary, so ask the building department.
Have a question this page did not answer? Call (855) 575-2890 at any hour and a dispatcher will talk it through.