How to Test Water Pressure
Updated February 20, 2026
Check your home's water pressure with a $10 gauge. Takes 2 minutes. Identifies high pressure (pipe damage risk) and low pressure (flow problems) before they cause trouble.
Overview
Water pressure that is too high damages pipes, fittings, and appliances. Too low and faucets trickle, showers are weak, and appliances will not fill properly. The ideal range is 40-60 PSI, with 80 PSI as the code maximum in most areas. A $10 pressure gauge screwed onto any hose bib tells you exactly where you stand in 2 minutes. Test at different times of day -- municipal pressure fluctuates with neighborhood demand. This is the diagnostic starting point for water hammer, low flow, dripping T&P valves, and PRV problems.
What You'll Need
Safety First
- No safety concerns for pressure testing. The gauge simply reads existing pressure.
- If you discover pressure above 80 PSI, do not ignore it. High pressure silently damages plumbing over time and voids some appliance warranties.
Step-by-Step Instructions
-
Get a Pressure Gauge
Buy a water pressure test gauge ($8-15) at any hardware store. It has a female hose thread connection and a dial or digital readout. Some have a lazy hand (red indicator) that records the peak pressure reached during the test -- useful for catching pressure spikes you would otherwise miss.
Tip: A gauge with a lazy hand is worth the extra $2-3. It shows you the highest pressure the system hit, not just the pressure at the moment you read it. Pressure spikes at night when demand is low are a common hidden problem. -
Connect to a Hose Bib
Find an exterior hose bib (spigot) or a laundry hookup. These connect directly to the supply line with no flow restrictions. Screw the gauge onto the hose bib hand-tight. Make sure no other water is running in the house -- all faucets off, no appliances running (dishwasher, washing machine, ice maker). You want static pressure, not dynamic.
Tip: Test at the hose bib closest to where the main water line enters the house. This gives you the truest reading of your incoming pressure before any pressure drop from internal piping. -
Read the Pressure
Turn the hose bib fully on. The gauge will jump to your static water pressure. Read the dial. Ideal: 40-60 PSI. Acceptable: 30-80 PSI. Below 30: low pressure problems likely. Above 80: high pressure -- PRV needed or existing PRV needs adjustment. Write down the reading.
Tip: If you have a PRV (pressure reducing valve) on your main line, the gauge reading at the hose bib shows the regulated pressure. To check incoming municipal pressure, test at a hose bib before the PRV if one exists, or ask your water utility. -
Test at Different Times
Pressure fluctuates with municipal demand. Test in the morning (6-8 AM, peak usage), midday (lower demand), and late evening (10 PM-midnight, lowest demand, highest pressure). If you have a lazy-hand gauge, leave it connected overnight and read the peak in the morning. Pressure above 80 PSI at any time means you need a PRV or your PRV needs servicing.
Tip: The biggest pressure spikes happen between midnight and 5 AM when neighborhood demand is lowest. If your morning reading is fine but you hear water hammer at night, overnight testing reveals the spike. -
Test Dynamic Pressure (Optional)
Static pressure is with nothing running. Dynamic pressure is while water is flowing. With the gauge connected, open two or three faucets inside the house and watch the gauge drop. A drop of 5-10 PSI is normal. A drop of 20+ PSI suggests undersized supply lines, partially closed valves, or heavy mineral buildup restricting flow.
Tip: If static pressure is fine but dynamic pressure drops significantly, the problem is internal -- not from the city. Check for partially open shut-off valves, corroded galvanized pipe, or undersized supply lines.
Pro Tips
- Keep the pressure gauge. Test annually. Pressure changes over time as city infrastructure ages, population grows, or your PRV degrades.
- If pressure is above 80 PSI, install or adjust a PRV. Target 50-60 PSI for the best balance of performance and pipe protection.
- If pressure is below 40 PSI and you are on city water, contact the water utility first. The problem may be on their side (main break, valve issue). If they confirm adequate street pressure, the restriction is in your plumbing.
- Well water systems: pressure is set by the pressure switch on the well pump. Typical settings are 30/50 or 40/60 (cut-in/cut-out). Adjusting the switch changes your house pressure.
- A pressure gauge is also the tool for checking your expansion tank pre-charge and diagnosing T&P valve issues. Buy one and keep it in the toolbox permanently.
When to Call a Pro
Testing pressure is always DIY. But call a plumber if pressure is consistently above 80 PSI and you need a PRV installed, if pressure is low and you cannot identify the restriction, if you need a pressure booster pump (for well systems or low city pressure), or if pressure fluctuates wildly (may indicate a failing PRV, waterlogged pressure tank, or city supply issue).