Start with the shower head itself
The fastest fix is often the simplest one: your shower head may be clogged with mineral buildup, or it may have a flow restrictor inside that limits water volume. Remove the shower head by turning it counterclockwise by hand (or with a wrench if it is stuck). Look inside the opening where water comes out—if you see white, chalky deposits, that is mineral scale.
Soak the shower head in a bowl of white vinegar for 30 minutes to an hour. Use an old toothbrush to scrub away the deposits, then rinse it thoroughly under running water. If you see a small plastic piece or screen inside the head, that is the flow restrictor—you can remove it carefully with needle-nose pliers, though this may void the warranty. Screw the head back on and test the pressure.
If the pressure is still low, try a different shower head altogether. Older heads often have lower flow rates by design. A new head costs $15 to $40 and installs in seconds—no tools needed beyond your hands.
Key Takeaways
- Mineral buildup inside your shower head is the most common cause of low pressure and can be cleared by soaking in vinegar and scrubbing with a brush.
- Flow restrictors built into shower heads can be removed to increase water volume, though this may affect your warranty.
- If the problem is only in one shower, the issue is almost certainly the head itself, not your home's water supply.
- Low pressure in all showers usually points to a valve problem or a clogged main line, which requires a plumber to diagnose.
- Adjusting the shut-off valve under the sink or behind the toilet can sometimes restore pressure if it was accidentally turned down.
Check the shut-off valve under your sink
Under the bathroom sink, you will find two shut-off valves—one for hot water and one for cold. These are small knobs or levers on the pipes coming out of the wall. If either one has been turned partway closed, it will reduce pressure to that line. Turn both valves all the way counterclockwise (or pull levers fully outward if they are lever-style) until they stop.
Run the shower again and check the pressure. If it improves noticeably, someone may have accidentally closed the valve while cleaning or working under the sink. If pressure is still low, turn the valves back to their original position and move to the next step.
Look for a pressure-balancing valve problem
Most modern showers have a pressure-balancing valve behind the wall that keeps hot and cold water in proportion so you do not get scalded when someone uses water elsewhere in the house. Over time, this valve can wear out or get stuck, reducing overall pressure.
If your shower pressure dropped suddenly and the shower head is clean, the valve may be failing. You can test this by turning off the water at the main shut-off valve (usually near the water meter or where the main line enters your home), then turning it back on slowly. Sometimes a stuck valve will free up with a sudden pressure surge, though this is temporary.
A failing pressure-balancing valve needs to be replaced by a plumber. This is not a repair you can do yourself—it requires opening the wall and soldering or connecting new pipes. Call a plumber if you suspect this is the problem.
Inspect the main water shut-off valve
If low pressure affects all the showers in your home, the problem is upstream of any individual fixture. Locate your main water shut-off valve—it is usually in the basement, crawl space, or outside near the foundation, depending on your climate. In cold climates, it is often inside near where the main line enters the house. In warm climates, it may be in a box in the yard.
The valve is typically a round knob or a lever. If it is a knob, turn it counterclockwise a quarter turn to see if pressure improves throughout the house. If it is a lever, make sure it is parallel to the pipe (fully open). Do not force it—if it is stuck, stop and call a plumber.
If the valve was partially closed and you have now opened it fully, pressure should improve. If pressure is still low everywhere, the problem may be a clogged main line or a failing pressure regulator, both of which require a plumber to diagnose.
Understand when you need a plumber
Call a plumber if low pressure affects all showers and fixtures in your home, or if it appeared suddenly without any change you made. A plumber can test your water pressure with a gauge (normal household pressure is 40 to 80 pounds per square inch) and identify whether the problem is a clogged line, a failing regulator, or a leak somewhere in your system.
You should also call a plumber if you suspect a pressure-balancing valve is failing, or if you have tried the steps above and pressure has not improved. Do not attempt to open walls or work on pipes behind fixtures yourself—that is where plumbers earn their fee.
Know the difference between low pressure and low flow
Low water pressure (weak stream) and low water flow (not much water coming out) can feel the same, but they are different problems. A clogged shower head causes low flow but not necessarily low pressure. A failing pressure regulator causes low pressure everywhere.
To tell the difference, turn on a sink faucet in another room while the shower is running. If the sink pressure is normal but the shower is weak, the problem is the shower head or the valve under the sink. If both are weak, the problem is your main water supply or a clogged main line.
Frequently Asked Questions
Can I remove the flow restrictor from my shower head?
Yes. Most shower heads have a small plastic piece or screen that limits water flow to meet federal standards. You can remove it with needle-nose pliers, which will increase flow when ready. Check your head's manual first—some warranties are voided if you remove it. Removing the restrictor does not damage the head and can be reversed.
What is normal water pressure for a shower?
Household water pressure ranges from 40 to 80 pounds per square inch (psi). Most people find 60 psi comfortable for a shower. If you suspect your pressure is abnormally low, a plumber can measure it with a gauge for $50 to $100. Many hardware stores also rent or sell inexpensive pressure gauges you can use yourself.
Why is pressure low in only one shower?
If one shower has low pressure but others do not, the problem is almost always that specific shower head or the valve under that sink. Clean the head with vinegar first, then check the shut-off valve. If both are open and clean, the pressure-balancing valve in that shower may be failing, which requires a plumber.
Will a new shower head really make a difference?
Yes, if your current head is old or heavily clogged. A new head costs $15 to $40 and installs in seconds. Even if your water pressure is genuinely low, a new head with a larger opening or removed flow restrictor will feel noticeably stronger than an old, clogged one.
Should I call a plumber or try to fix this myself?
Start with the shower head and the shut-off valve under the sink—both take five minutes and cost nothing. If pressure is still low after cleaning the head and opening the valve, and if low pressure affects multiple fixtures, call a plumber. Do not open walls or work on pipes yourself.