If the shower in your St. Louis home suddenly sprays weakly, sputters, or sends water off to one side, the most common cause is mineral scale building up in the small outlet holes of the head. Hard water is common across the St. Louis area, and calcium and other minerals settle out of the water and narrow those openings over time. Before you buy a new head, work through the checks below in order.
First, see whether the whole house is weak
Run the bathroom sink or kitchen faucet while the shower is on. If every fixture is weak, the problem is likely in the plumbing rather than the head, and cleaning the head alone will not solve it. If only the shower is weak, the head, its arm, or the valve behind it is the likely source.
Look closely at the spray face
Unscrew the head from the arm by hand, or wrap a cloth around it before using a wrench so the finish is not scratched. Hold the face up to good light. White, chalky, or crusty rings around the holes point to scale. Dark specks or grit point to debris carried in from the supply line or the water heater.
Clean the head at home
- Wipe the face and rubber washer with a soft cloth to remove loose residue.
- Fill a plastic bag with white vinegar, tie it around the head so the holes are fully covered, and leave it overnight.
- Rinse the head well, then gently scrub each hole with a soft brush or an old toothbrush. Avoid metal pins or sharp tools that can scratch or enlarge the openings.
- Reinstall the head with the rubber washer in place. Hand-tighten it, then add only a light turn with a cloth.
Scale that has already formed on a head usually needs direct cleaning. Changing the water going into the home does not dissolve what is already built up, so the head itself needs attention.
Check the screen and the arm
Many heads have a small screen or flow restrictor at the connection to the shower arm. Unscrew the head from the arm and look inside the threaded end for a washer or mesh screen. Rinse it under running water and remove any grit. Then run water through the arm itself with the head off. If the flow is strong at the arm but weak at the head, the head is restricting it. If the arm trickles, the arm may be scaled or partly blocked and should be cleaned the same way.
Check the shutoff valves
A partly closed shutoff valve can reduce flow to the shower, especially after recent plumbing work. Locate the supply valves behind an access panel, under a sink, or at the shower valve if your home has one. Make sure each handle is fully open. Valves that have sat unused for years can also stick partway, so turn them gently and watch for leaks at the stem.
When the cause is in the plumbing
If every fixture in the house is weak, look at the main shutoff, any pressure regulator on the line, and any sediment filter that may be clogged. Sediment from aging pipes or work on nearby service lines can reduce flow across the whole home. Your water provider publishes an annual water quality report, and reading it can give you a general sense of the hardness and other conditions in your area. That report describes the water leaving the treatment plant, not the water inside your own pipes, so it is a starting point rather than a diagnosis.
Test your water if scale keeps coming back
If the head clogs again within a short time after cleaning, a home test can help you understand how hard your water is. Test strips show a general range and are simple to read at the kitchen sink. A sample sent to a certified lab gives a more detailed result. Either way, use the result to decide how often you will need to clean fixtures, not as proof of any particular outcome.
When cleaning is not enough
- The face is cracked, warped, or pitted, and the holes no longer hold their shape.
- Water leaks at the joint between the head and the arm even after the washer is replaced.
- The spray stays weak after a second round of cleaning.
- The arm itself is badly scaled or corroded at the threads.
In any of these cases, the head or arm is worn beyond cleaning, and replacing that part is the practical next step. Keep the old part until the new one is working, in case the trouble was somewhere else.
Keep the spray clear
Wipe the face with a dry cloth after each shower, which slows the drying that leaves mineral rings behind. Clean the head on a regular schedule, and check the screen whenever the spray seems to change. A few minutes of attention now usually saves a larger repair later.