Scaled shower head
Mineral buildup blocks nozzles; the spray turns uneven and weak.
Shower Low Water Pressure
The shower trickles or sprays unevenly, while sinks and other fixtures seem normal.
Short answer
When only the shower is weak, the cause is in the shower: a shower head clogged with scale, a flow restrictor, a worn cartridge or a partly closed stop behind the wall. When every fixture is weak, look at the main valve, the water heater for hot-only problems, or the water supply itself.
Likely causes
Worn or clogged cartridge
Debris or wear inside the valve restricts flow.
Partly closed stop
Some showers have small stops behind the trim or access panel.
Hot-side issue
If only hot water is weak, sediment in the heater or a hot-line valve may be to blame.
In high-rise condos, upper floors depend on the building's booster pumps, so a building-wide drop is something to raise with management. In single-family homes, old galvanized pipes narrow inside and reduce flow everywhere. The pressure repair page covers how a plumber tests and traces the cause. Some shower valves have small screens or check valves at the inlets that catch debris after water work in the street. Clearing them restores flow without replacing anything. If the weak flow is only on the hot side, the water heater's outlet or the hot supply line is the next place to look.
Safe first steps
- Unscrew the shower head and run the water without it to compare flow
- Soak the head in white vinegar overnight to dissolve scale
- Check whether the problem is hot only, cold only or both
- Test a nearby sink to see whether pressure is low everywhere
- Ask neighbors or check with the water utility if pressure is low throughout
When to call a plumber
Call when flow is weak even without the shower head, temperature also swings, only hot water is weak, or pressure is low across the house.
Services that fix this
Calling from one of the eight cities
Shower low water pressure: questions
A scaled shower head, a clogged cartridge or a partly closed stop.
Only if the old head is clogged. All new heads are flow-limited by federal rules.
Sediment in the water heater or a problem in the hot line or valve.
Shower heads are required to limit flow. Clean the head rather than removing parts.
Possible causes include utility work, a hidden leak or a failed valve. Check other fixtures and neighbors.
Mineral scale builds up over time. Periodic soaking in vinegar helps.
Upper floors rely on the building's pumps. Contact management for building-wide issues.
A large hidden leak can lower pressure across the house. Check the meter with all water off.
Yes. Flow-limited heads vary; some feel stronger than others at the same flow rate.
Debris from the work can clog the cartridge screen. A plumber can clear it.