Low Water Pressure in Your Home: Causes, Fixes, and When to Call

If your shower feels weak or your sink takes forever to rinse, you’re not alone. Low water pressure can show up in a single faucet, on one floor, or across the whole home. Sometimes it’s a quick fix. Other times, it points to a bigger issue that needs pro testing.

At H.I.S. Plumbing, we handle emergency plumbing calls around the clock. This guide walks you through safe steps to diagnose low pressure, what you can fix today, and when to call for code‑compliant repairs that last.

Quick Checks 🔧

Before you worry about major repairs, try these simple checks. Many pressure problems start with small blockages or closed valves.

• Clean faucet aerators and showerheads:
  • Unscrew the aerator or showerhead.
  • Soak in warm vinegar for 30–60 minutes to break down mineral scale.
  • Rinse and brush with an old toothbrush.
  • Reinstall and test the flow.
• Make sure supply valves are fully open:
  • Under-sink and toilet stop valves should be fully open. Turn counterclockwise to open.
  • Check the main shutoff valve (usually by the water meter or where water enters the house). Gate valves should be turned fully counterclockwise. Lever-style ball valves should be in line with the pipe, not perpendicular.
• Compare hot vs. cold to isolate the issue:
  • If cold water pressure is strong but hot is weak, the restriction is likely on the water heater side. Sediment buildup in the heater, a clogged heat-trap nipple, or a partially closed valve can all cause this.
  • If both hot and cold are weak at one fixture, the fixture or local supply may be restricted.
  • If both are weak throughout the house, look at whole-home causes like your pressure regulator, meter screen, or main line.

Pro tip: After you clean aerators, run the water for 20–30 seconds to flush any loose debris.

Whole-Home Issues 🏠

When pressure is poor at many or all fixtures, it’s time to check the main parts of your system.

• Pressure regulator valve (PRV) failure:
  • What it does: A PRV reduces high street pressure to a safe level for your home.
  • Signs it’s failing:
    • Pressure that drifts high or low during the day
    • Hammering, whistling, or chattering pipes
    • Weak flow upstairs but not downstairs
    • Pressure spikes that improve when you briefly crack open a fixture
  • Typical lifespan: Many PRVs last 7–15 years, depending on water quality and usage.
  • Replacement notes:
    • Codes such as the International Plumbing Code (IPC) and Uniform Plumbing Code (UPC) require a PRV when static pressure exceeds 80 psi.
    • When a PRV is installed, your system may be considered “closed,” which often requires a thermal expansion tank on the water heater to protect against pressure spikes.
• Aging galvanized steel lines:
  • Older galvanized pipes corrode from the inside, forming rough “tubercles” that choke water flow.
  • Clues include brownish water after the system sits, uneven pressure, and short bursts of flow that drop off.
  • Repiping with copper (Type L) or PEX is a long-term fix. Spot repairs can help, but widespread corrosion usually calls for replacement.
• Mineral buildup from hard water:
  • Scale collects inside valves, PRVs, angle stops, and fixture cartridges.
  • In hard-water regions, scale can reduce pipe diameter and clog heater dip tubes, heat-trap nipples, or recirculation check valves.
  • Water treatment or a whole-home filtration/softening system can protect new parts from scaling up again.
• Meter screen or curb stop restrictions:
  • Some meters have small inlet screens that can clog with debris after line work in your street.
  • If you can’t access the meter, a licensed plumber or the water utility can help check and clear it.
• Partially closed or failing main shutoff valve:
  • A failing gate valve can shed pieces of its internal gate, restricting flow. Lever-type ball valves are more reliable.

If your home has a PRV, aging pipes, or local roadwork recently disturbed the main, any of these can create a whole‑home drop in pressure.

Testing and Measurement 📏

Guessing leads to wasted time. A $15–$25 pressure gauge can give you real numbers and a clear direction.

• How to test static pressure:
  • Screw a gauge onto an outdoor hose bib closest to where water enters your home.
  • Make sure all fixtures inside are off.
  • Open the hose bib and read the gauge. This is your static pressure.
• Check dynamic (flowing) pressure:
  • Keep the gauge attached.
  • Have someone open a tub or two fixtures indoors.
  • Watch the gauge as water flows; note how much pressure drops. A large drop can mean restrictions or undersized piping.
• Ideal PSI ranges:
  • Many homes feel best at 50–70 psi.
  • Codes require pressure-reducing measures when static pressure exceeds 80 psi.
  • Some appliances and fixtures list maximum pressure ratings; most are tested up to 80 psi.
• Pressure that’s too low:
  • Below 40 psi can feel weak, especially upstairs or in multi-fixture use.
  • Under 30 psi often indicates a supply or regulator issue that needs attention.
• Pressure that’s too high:
  • Over 80 psi adds stress to pipes, water heaters, flexible connectors, and appliance valves. It increases leak risk and can trigger relief valves to drip.
• When to consider a booster:
  • If your static pressure from the city supply is consistently below 40–45 psi, and your home is otherwise in good shape, a booster pump and small pressure tank can stabilize flow.
  • Work with a licensed plumber to size the pump and add required check/backflow devices. Follow local code and water authority rules.
• When to consider repiping:
  • Chronic rust or debris in water, widespread galvanized pipe, constant pressure dips, or pinhole leaks in copper can signal it’s time.
  • Repiping can also fix mixed-diameter “patchwork” that creates friction losses.

Write down your static and dynamic readings. These numbers help pros diagnose quickly and avoid replacing the wrong parts.

Special Cases 🌊

Some systems and house layouts need extra thought.

• Well systems: pressure tank and switch basics
  • Typical factory settings are 30/50 or 40/60 psi (cut-in/cut-out).
  • If pressure cycles rapidly (short cycling), your pressure tank may be waterlogged or undersized. Check the tank’s air charge with the power off and system drained; it should be 2 psi below the cut-in setting.
  • A clogged well screen, failing pump, or blocked check valve can also lower pressure.
  • Do not open electrical panels or attempt pump service unless you’re trained. Call a licensed pro for well diagnostics.
• Multi-story homes: height and friction losses
  • Water loses about 0.43 psi for every foot of elevation. A second floor 20–25 feet above the meter can drop roughly 9–11 psi.
  • Long pipe runs, tight elbows, old valves, and small pipe diameters add friction loss.
  • Solutions include a properly set PRV, strategic upsizing, low-resistance fittings, or a booster system.

Problem/Scenario: Where Low Pressure Shows Up At Home 🧭

Low water pressure can be spotty or system-wide. Match your situation to a likely cause.

• One faucet or shower only
  • Likely causes: clogged aerator, calcified showerhead, failing cartridge, partially closed stop valve, kinked flex connector.
  • Try first: Clean fixtures, open valves, replace cartridge.
• Hot water weak, cold water normal
  • Likely causes: sediment in the water heater, clogged heat-trap nipples, partially closed heater valve, failing mixing valve.
  • Try first: Flush the water heater per manufacturer instructions; check inlet/outlet valves; inspect and replace clogged nipples or filters where applicable.
• One bathroom group weak (sink, tub, shower)
  • Likely causes: local branch restriction, old angle stops, shared 3/8-in. supplies, mineral buildup in the manifold.
  • Try first: Replace angle stops and supply lines; check for shared restrictions.
• Upstairs weak, downstairs normal
  • Likely causes: PRV set too low, insufficient static pressure, friction losses in long runs, or undersized main.
  • Try first: Measure pressure; adjust PRV within safe range; consider booster if supply is low.
• Whole house weak
  • Likely causes: failed PRV, meter screen debris, partially closed main valve, aging galvanized system, municipal supply issues.
  • Try first: Confirm main valve is fully open; measure pressure at hose bib; call the water utility to ask about supply changes or recent repairs.

Quick Safety Checklist ⚠️

• Turn off power to an electric water heater before draining or flushing.
• Let hot water lines cool before removing cartridges or supply lines.
• Do not overtighten fixture connections; use two wrenches to back up when needed.
• Use thread sealant or tape only where needed (never on compression threads).
• If you smell gas, hear hissing, or see continuous water flow you can’t stop, evacuate and call for emergency plumbing help.
• Know your main water shutoff location and test it lightly so it turns when you need it.

DIY vs. Call a Pro 🤝

DIY can solve simple restrictions. For anything beyond cleaning or basic parts replacement, a licensed plumber protects your home, your time, and your warranty.

Try DIY if:

• Cleaning aerators and showerheads
• Replacing a faucet cartridge or shower cartridge with manufacturer instructions
• Flushing a water heater if you’re comfortable and the valves operate smoothly
• Replacing under-sink angle stops and supply lines
• Installing a simple pressure gauge and recording readings

Call H.I.S. Plumbing if:

• Static pressure is above 80 psi or below 35–40 psi and won’t hold steady
• You suspect a failing PRV or need one installed or replaced
• Your home has galvanized steel piping or mixed, aging materials
• The water heater has heavy sediment, popping noises, or a stuck valve
• There’s a constant leak, slab moisture, or signs of hidden water damage
• You have a well system with short cycling or unreliable pressure
• You’re considering a booster, repiping, or code-required backflow prevention

We handle emergency plumbing calls day and night. When a pressure problem turns into a leak, clogged main, or heater failure, we can be on the way.

What Pros Do On Arrival 🧰

Here’s what an H.I.S. Plumbing technician typically checks and why it matters:

• Interview and walk-through
  • We ask where and when pressure is low, what changed recently, and what you’ve tried.
  • We look for obvious issues: closed valves, kinked connectors, wet spots, and corrosion.
• Measured testing
  • Static and dynamic pressure readings at hose bibs and selected fixtures
  • Cross-check hot vs. cold to isolate heater-side restrictions
  • If needed, flow tests at tub spouts or laundry faucets to measure gallons per minute
• PRV assessment
  • Inspect make, model, age; check pressure setpoint and responsiveness
  • Adjust within safe ranges if possible; replace if the valve drifts, chatters, or won’t hold
• Water heater checks
  • Inspect inlet/outlet valves, heat-trap nipples, and sediment levels
  • Verify thermal expansion tank charge and condition if present
  • Check temperature and pressure relief (TPR) valve operation
• Pipe and valve evaluation
  • Look for galvanized sections, old gate valves, and constricted fittings
  • Use point-of-use checks to narrow down hidden restrictions
• Leak detection when needed
  • Acoustic listening, pressure decay, or thermal checks can pinpoint hidden leaks
  • If the meter moves when all water is off, we track down where the water is going
• Clear findings and options
  • We explain test results, show you the numbers, and lay out repair paths
  • We provide clear, itemized quotes before work starts

Our installs follow code. That includes PRV placement, thermal expansion control where required, and proper support of new piping.

Prevention & Maintenance 🛠️

You can keep good pressure and protect your system with simple yearly habits.

• Flush the water heater
  • Most manufacturers recommend annual or semiannual flushing, especially in hard-water regions.
  • Add a sediment filter or whole-home filtration system if debris is common.
• Clean and cycle valves
  • Turn under-sink stops and the main shutoff once or twice a year to prevent seizing.
  • Replace crusted or frozen valves before they fail.
• Check your pressure
  • Keep a gauge on hand. Spot-check static pressure in spring and fall.
  • If you see high pressure at night (when city demand drops), consider adjusting or replacing your PRV.
• Treat hard water
  • Filtration or softening reduces scale in fixtures, cartridges, and PRVs.
  • Protects water heaters, extending the time between flushes and improving performance.
• Schedule routine plumbing checkups
  • An annual inspection can catch leaking angle stops, aging supply lines, and slow PRV drift before they cause damage.
  • If you use gas appliances, schedule gas safety checks together with plumbing maintenance.

Costs & Time Factors ⏱️

Actual costs depend on access, parts, and local code needs, but here are the major drivers:

• Quick fixes
  • Cleaning aerators or changing cartridges: low cost, often under an hour.
• PRV adjustments vs. replacement
  • Adjustment is fast. Replacement takes longer and may require permits.
  • Adding a thermal expansion tank can be part of code-compliant upgrades.
• Water heater maintenance
  • Flushing is relatively quick; heavy sediment or failing valves add time.
  • Heat-trap nipples or mixing valves may need replacement when clogged.
• Repiping or section replacements
  • Replacing angle stops and connectors: quick
  • Replacing galvanized sections or whole-home repiping: multi-day
• Booster systems
  • Sizing, installing, and commissioning a booster with a small tank typically takes a day once permits are in place.
• Leak detection and repairs
  • Hidden leaks increase diagnostic time; slab or wall repairs add restoration steps.

Clear quotes matter. H.I.S. Plumbing explains options and expected time so you can plan.

When It’s an Emergency 🚨

Call emergency plumbing right away if you have:

• A sudden pressure drop with visible water damage or pooling
• A burst line, failed washing machine hose, or spraying angle stop
• A water heater leaking or TPR valve discharging continuously
• Sewer backup, gurgling drains, or toilets that won’t flush along with pressure issues
• Gas smell, hissing near gas lines, or alarms going off

If safe to do so, shut off the home’s main water valve and electricity to a leaking electric water heater. For gas leaks, evacuate immediately.

FAQ ❓

• Is 80 psi too high?
  • It’s the upper limit per common plumbing codes. Above 80 psi, a PRV is required. Many homes feel best around 50–70 psi.
• Why is hot water pressure lower than cold?
  • Sediment in the water heater, clogged heat-trap nipples, or a mixing valve issue can choke the hot side. Flushing or part replacement often helps.
• Will a larger water heater fix low pressure?
  • Not directly. Tank size affects hot water volume, not pressure. Pressure depends on supply, PRV setting, piping, and restrictions.
• Do I need a booster pump?
  • Only if city or well supply can’t maintain reasonable static pressure and adjustments won’t solve it. Measure first, then size a booster if needed.

Local/Seasonal Considerations 🌦️

• Seasonal demand swings
  • In many areas, pressure is lower in the mornings and evenings when neighborhood demand is high. Late-night pressure often spikes. A healthy PRV smooths these swings.
• Construction and street work
  • Main repairs or hydrant use can stir up sediment, clogging meters, PRVs, and aerators. If your pressure fell right after nearby work, clean aerators and check your PRV.
• Freezing conditions
  • Partially frozen pipes restrict flow and can burst as they thaw. If a section stops flowing in cold weather, shut off water and call for help before pipes split.
• Hard-water regions
  • Expect more scale. Plan for regular heater maintenance, periodic PRV checks, and fixture cleaning.

Quick Checks (Recap) 🔁

• Clean aerators and showerheads; verify supply valves are fully open.
• Compare hot vs. cold to isolate heater-side restrictions.
• Check static and dynamic pressure with a gauge.
• Note PRV age and behavior; watch for drift, noise, or pressure spikes.
• If your home uses galvanized piping or has recurring debris, plan a longer-term fix.

Whole-Home Issues (Recap) 🧩

• PRV failure signs, typical 7–15 year lifespan, and safe replacement with an expansion tank where required.
• Aging galvanized lines and mineral buildup, especially in hard-water regions.
• Partially closed main valves and clogged meter screens.

Testing and Measurement (Recap) 🧪

• Gauge on hose bib for static and flowing pressure.
• Ideal range 50–70 psi; keep under 80 psi per code.
• Consider a booster if supply is low, or repiping if friction losses and corrosion are widespread.

Special Cases (Recap) 🧭

• Well systems: 30/50 or 40/60 psi basics; tank precharge 2 psi below cut-in.
• Multi-story homes: 0.43 psi loss per foot of rise; plan PRV settings, pipe sizing, or a booster to compensate.

Services That Often Solve Low Pressure 🔨

H.I.S. Plumbing can help with:

• Pressure regulator valve replacement and code-compliant installs
• Leak detection, pipe repair, and repiping
• Water heater flushing, heat-trap nipple replacement, and expansion tanks
• Fixture cartridge swaps, angle stop and supply line upgrades
• Booster pump sizing and installation with proper backflow prevention
• Drain cleaning when clogs mimic “low pressure” at tubs and sinks
• Backflow testing and prevention for safe, compliant systems

Why Call H.I.S. Plumbing For Low Water Pressure 🧡

• Accurate testing
  • We document static and dynamic readings and show you the numbers.
• Code‑compliant installs
  • PRVs, expansion tanks, and backflow assemblies installed to local code and manufacturer specs.
• Clear quotes
  • You’ll see the work plan and pricing before we start.
• 24/7 availability
  • When pressure problems turn urgent, you can reach emergency plumbing near you anytime.

Sources and Standards We Follow 📚

• International Plumbing Code (IPC) and Uniform Plumbing Code (UPC): PRV required when static pressure exceeds 80 psi; installation and safety provisions.
• American Water Works Association (AWWA) guidance on pressure management and distribution system operation.
• Manufacturer instructions for PRVs, water heaters, thermal expansion tanks, and booster pump systems.
• EPA WaterSense for fixture performance expectations and conservation best practices.
• Local water authority rules for backflow prevention and meter access.

Keeping your system within these standards protects your home and helps fixtures last longer.

Final Thoughts: Start Small, Measure, Then Decide 🧩

Most low water pressure issues start with simple restrictions and easy fixes. Clean the fixtures, check your valves, and take pressure readings. If the problem points to your PRV, heater, or piping, bring in a licensed team that tests first and repairs to code.

From quick aerator cleanups to PRV replacements, booster installs, and repiping, H.I.S. Plumbing is ready to help—day or night.

Call H.I.S. Plumbing now — or reach us anytime at  1-888-778-7167 .