Low Water Pressure: Common Causes and When to Call a Plumber

Editorially reviewedBy the Home Services Resource Center Editorial TeamLast reviewed: June 2026

This guide is written to help homeowners understand common plumbing repair, installation, water heater, drain, and emergency considerations. It is educational and is not a substitute for an on-site evaluation by a licensed plumber. HSRC does not perform work directly, set contractor pricing, or guarantee availability — services and response times vary by location and provider.

Quick Answer

Low pressure at one fixture is usually a clogged aerator, cartridge, or supply valve. Low pressure throughout the home usually points to a pressure-reducing valve issue, a leak, corroded pipes, or a municipal supply issue.

Key Takeaways

Single-fixture vs. whole-home matters
Aerators are an easy first check
PRV failures are common and fixable
Sudden whole-home drops can indicate a leak

Single-fixture causes

Clogged aerator, cartridge buildup, partially closed shutoff valve, sediment in the supply line.

Whole-home causes

Failed pressure-reducing valve, large leak in the supply line, partially closed main valve, corroded galvanized pipes, or municipal supply issue.

Ready for the next step?

Get connected with a local licensed plumber, or call the plumbing line.

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Frequently asked questions

Is low pressure an emergency?

Usually no, unless it suddenly drops to zero — which can indicate a major leak or supply issue.