Why Low Water Pressure Happens and How to Fix It
- Dec 24, 2025
- 2 min read
Low water pressure can turn simple activities like showering, washing dishes, or doing laundry into a daily frustration. While the issue may seem minor, low water pressure often points to deeper plumbing problems that should not be ignored.

Understanding what causes low water pressure helps homeowners identify whether the issue can be resolved easily or requires professional attention.
1. What Is Considered Low Water Pressure?
Water pressure is measured in pounds per square inch (PSI).
Typical Residential Water Pressure
Normal range: 40–60 PSI
Below 40 PSI: Considered low
Pressure consistently below the recommended range may affect plumbing performance and appliance efficiency.
2. Common Causes of Low Water Pressure
Several factors can restrict water flow in a home.
Most Frequent Causes
Mineral buildup in pipes
Clogged fixtures or aerators
Partially closed shutoff valves
Aging or corroded pipes
Hidden plumbing leaks
Identifying the source is key to solving the problem.
3. How Mineral Buildup Affects Water Pressure
Hard water leaves mineral deposits inside pipes and fixtures.
Effects of Mineral Scale
Narrowed pipe diameter
Reduced water flow
Increased strain on plumbing
Over time, buildup can significantly reduce pressure throughout the home.
4. Checking Fixtures and Aerators
Sometimes low pressure is limited to one fixture.
Simple Troubleshooting Steps
Remove and clean faucet aerators
Check showerheads for mineral buildup
Inspect flexible supply lines
Cleaning fixtures can restore normal pressure quickly.
5. Valve Issues That Reduce Pressure
Water shutoff valves control water flow.
Valves to Check
Main shutoff valve
Water meter valve
Fixture-specific shutoffs
Valves that are partially closed restrict water flow and reduce pressure.
6. Hidden Leaks and Water Pressure Loss
Leaks divert water away from fixtures.
Signs of Leak-Related Pressure Loss
Sudden pressure drop
Unexplained water bill increases
Damp spots or mold
Professional leak detection may be required to locate hidden leaks.
7. Aging Plumbing Systems and Pressure Problems
Older homes may have outdated piping materials.
Common Issues in Older Pipes
Corrosion
Internal rust buildup
Restricted flow
Pipe replacement may be necessary for long-term improvement.
8. When Low Water Pressure Is a Municipal Issue
Sometimes the issue originates outside the home.
Possible External Causes
Water main repairs
High neighborhood demand
Municipal pressure regulations
A plumber can help determine whether the issue is internal or external.
9. When to Call Shamrock Plumbing
Professional assistance is recommended if:
Pressure issues affect multiple fixtures
DIY troubleshooting doesn’t help
Leaks are suspected
Pipes are old or corroded
Shamrock Plumbing uses advanced diagnostic tools to identify pressure problems and provide lasting solutions.
Restore Comfort With Proper Water Pressure
Low water pressure is more than an inconvenience — it can indicate serious plumbing concerns. Early diagnosis and professional service help restore reliable water flow and protect your plumbing system.
Shamrock Plumbing is committed to helping homeowners enjoy consistent water pressure through expert plumbing solutions, inspections, and repairs.




