Water Pressure Issues Diagnostics

Purpose

Diagnostic procedures for water pressure problems.

When to Use

• Low pressure, high pressure, fluctuating pressure, water hammer

Testing

Attach gauge to exterior hose bib closest to main

All fixtures OFF for static test — normal is 40-80 PSI

Run multiple fixtures for dynamic test — note pressure drop

High Pressure (Above 80 PSI)

Check for PRV — is one installed?

PRV present: test by adjusting — may be set too high or failing

No PRV: recommend installation — high pressure damages fixtures and piping

Check expansion tank — failed tank plus high pressure accelerates damage

High pressure causes running toilets, drips, premature water heater failure

Low Pressure (Below 40 PSI)

Check PRV — set too low, failing, or clogged

Check main shutoff valve — partially closed restricts flow

Check for supply line leaks

Well water: check pressure tank and switch settings

Old galvanized pipe: internal corrosion restricts flow

Fluctuating Pressure

Well: check pressure tank pre-charge and switch

City: may be municipal issue — check with neighbors

Check expansion tank on water heater

Water Hammer

Caused by sudden valve closure creating pressure shockwave

Check for hammer arrestors — recommend installation if absent

High pressure worsens hammer — address pressure first

Secure loose pipes that amplify noise

Important Notes

• Pressure check should be part of every diagnostic visit
• Document readings with photo of gauge in ServiceTitan
• High pressure is a silent killer of plumbing — customers often unaware
• Recommend PRV on every home without one — legitimate safety upgrade

Related SOPs

• Well Pump Diagnostics — well-specific pressure
• Water Heater Diagnostics — pressure impacts on water heaters