Solving Low Water Pressure: From Simple Fixes to Major Repairs

Low water pressure transforms quick showers into frustrating marathons and makes filling pots take forever. Six causes account for 95% of pressure problems, from five-minute aerator cleaning to major pipe replacement costing thousands.

Start with simple fixes that solve 40% of pressure complaints, then progress toward solutions requiring professional expertise.

Check if the Problem is Localized or Whole-House

Before diagnosing specific causes, determine whether low pressure affects a single fixture or the entire house.

Turn on multiple faucets simultaneously in different locations. If one fixture has weak flow while others run normally, the problem is localized to that fixture or supply line.

If all fixtures show reduced pressure, you have a whole-house problem requiring different solutions.

Quick Fix #1: Clean Faucet Aerators

Aerators screw onto faucet spouts, mixing air with water for smooth flow while reducing water consumption. Mineral deposits clog the screen, drastically reducing pressure.

Symptoms

One faucet has weak or erratic spray while others work fine.

Water sprays sideways or in irregular patterns rather than a single smooth stream.

Pressure from that faucet has declined gradually over months.

Fix

Unscrew the aerator by turning it counterclockwise. Use a wrench or pliers wrapped in a cloth if it won't turn by hand. Aerators have flat sides designed for wrench use.

Disassemble the aerator. Most have a screen, washer, and flow restrictor. Note the order for reassembly.

Soak all parts in white vinegar for 30 minutes. The acid dissolves mineral deposits.

Scrub the screen with an old toothbrush to remove remaining deposits.

Rinse all parts with water and reassemble.

Screw the aerator back onto the faucet.

Test water pressure. Most clogged aerators restore full pressure immediately after cleaning.

Time required: 5-10 minutes Cost: $0

If cleaning doesn't restore pressure, replace the aerator. They cost $3-$8 and install in seconds. Bring the old aerator to the hardware store to match thread size.

Quick Fix #2: Check Shutoff Valves

Every fixture has shutoff valves on supply lines beneath sinks or behind toilets. Partially closed valves restrict flow.

Symptoms

Pressure dropped suddenly rather than gradually.

The problem started after plumbing work or fixture replacement.

Fix

Locate the shutoff valves under the affected fixture. Most are oval handles or small round knobs on pipes.

Turn the valve counterclockwise until it stops. This is the fully open position.

Test the fixture. If pressure returns to normal, the valve was partially closed.

Time required: 30 seconds Cost: $0

Shutoff valves sometimes stick partially closed or don't open completely. If the valve won't turn easily or doesn't improve pressure when opened, it may need replacement.

Valve replacement costs $10-$25 for parts if you do it yourself, $100-$200 if you hire a plumber.

Quick Fix #3: Check Your Main Shutoff Valve

The main water shutoff controls flow to your entire house. Partially closing this valve reduces pressure everywhere.

Symptoms

Whole-house pressure dropped suddenly.

Recent plumbing work may have left the main valve partially closed.

Fix

Locate your main water shutoff. This is typically where the water line enters your house, in the basement, crawl space, or garage.

Gate valves (with round wheel handles) should be turned fully counterclockwise until they stop.

Ball valves (with lever handles) should be parallel to the pipe when fully open.

If your valve was partially closed, open it completely and test pressure throughout the house.

Time required: 1 minute Cost: $0

Pressure Regulator Problems

Pressure regulators (also called pressure-reducing valves or PRVs) control municipal water pressure entering your home. Not all homes have these devices, but those that do can experience pressure problems when regulators fail.

Symptoms

Whole-house pressure dropped over days or weeks.

Municipal pressure is known to be high (over 80 PSI).

You can see a bell-shaped device on the main water line where it enters your house.

Identifying a Pressure Regulator

Look for a bell-shaped brass or bronze device on your main water line. It's usually within a few feet of where the water meter or main shutoff valve is located.

The device will have an adjustment screw on top, often under a cap.

If you don't have one of these devices, your home doesn't have a pressure regulator. Skip to the next section.

Adjusting the Pressure Regulator

Attach a pressure gauge to an outdoor hose bib or washing machine supply line. Pressure gauges cost $10-$20.

Read the current pressure with water flowing. Normal residential pressure ranges from 40-80 PSI. Optimal pressure is 50-60 PSI.

Locate the adjustment screw on top of the regulator. You may need to remove a protective cap.

Turn the screw clockwise to increase pressure, counterclockwise to decrease it. Small adjustments make big differences.

Make quarter-turn adjustments, then test pressure. Repeat until reaching desired PSI.

If adjusting doesn't affect pressure or the regulator won't hold consistent pressure, it has failed and needs replacement.

Replacing a Failed Pressure Regulator

Failed regulators require professional replacement in most cases. The regulator connects to the main water line using threaded or compression fittings.

Replacement costs $250-$500 including parts and labor.

Pressure regulators last 7-12 years typically. If yours is over 10 years old and showing problems, replacement makes more sense than repeated adjustments.

Time required: 15 minutes to adjust, 1-2 hours for replacement Cost: $10 for gauge, $250-$500 for replacement

Municipal Supply Pressure Problems

Sometimes the issue isn't your plumbing but the water utility's supply pressure.

Symptoms

Neighbors report similar pressure problems.

Pressure is consistently low throughout the day or drops during peak usage times (mornings and evenings).

Solution

Call your water utility and report low pressure. They can check system pressure and their records of pressure complaints.

Municipal pressure below 40 PSI at the meter indicates system problems. Utilities are responsible for maintaining adequate pressure to the meter.

If municipal pressure is adequate but you still have low pressure, the problem is in your home's plumbing.

For homes at high elevations or far from water mains, municipal pressure may be chronically low. Consider installing a booster pump system. These cost $800-$2,000 installed and increase pressure to desired levels.

Time required: 10-minute phone call Cost: $0 (utility responsibility) or $800-$2,000 for booster pump

Corroded or Clogged Pipes

Older homes with galvanized steel or iron pipes often develop internal corrosion and mineral buildup that restricts flow.

Symptoms

House is over 40 years old with original plumbing.

Pressure has declined gradually over years.

Some fixtures have rusty or discolored water.

Replacing aerators and cleaning fixtures provides only temporary improvement.

Diagnosis

Look at exposed pipes in basements or crawl spaces. Galvanized steel pipes look silver-gray and may show rust on exteriors.

Check pipe diameter. The actual interior may be significantly smaller than original diameter due to buildup.

Have a plumber perform a pressure test at the main water line and again at various fixtures. Significant pressure loss between points indicates pipe restriction.

Solutions

Pipe Descaling

For moderate buildup in copper or galvanized pipes, professional descaling services use specialized equipment to break up mineral deposits without pipe replacement.

Cost: $800-$2,000 for whole-house treatment

Descaling extends pipe life 5-10 years but doesn't solve severe corrosion.

Partial Repiping

Replace the worst sections while leaving functional pipes in place. This works when problems concentrate in specific areas.

Cost: $1,500-$5,000 depending on scope

Whole-House Repiping

Severely corroded systems need complete replacement. Modern PEX or copper piping restores full pressure and lasts 50+ years.

Cost: $4,000-$12,000 for typical homes

Repiping makes sense when pipes are over 50 years old, show multiple problems, or descaling provides insufficient improvement.

Time required: Professional diagnosis 1-2 hours Cost: $800-$12,000 depending on solution

Water Softener Problems

Homes with water softeners may experience pressure loss when softeners malfunction.

Symptoms

Pressure dropped after softener installation or recent service.

Pressure is lower after the softener regenerates.

Some fixtures (usually outdoors) have normal pressure while indoor fixtures don't.

Diagnosis

Bypass the water softener using the bypass valve. This routes water around the softener directly to house plumbing.

Test pressure with the softener bypassed. If pressure returns to normal, the softener is causing restriction.

Solutions

Check softener settings. High service flow rates or improper configuration can restrict pressure.

Clean or replace the sediment filter if your system has one. Clogged filters drastically reduce flow.

Regenerate the softener manually. Sometimes depleted resin beds restrict flow until regeneration occurs.

If problems persist, the softener resin bed may be fouled or the control valve may have failed. Professional service costs $200-$400.

Undersized softeners can't deliver adequate flow for household demands. If your softener is too small, upgrading to a properly sized unit solves the problem.

Time required: 15 minutes for bypass test Cost: $0-$400 for professional service

Leaking Pipes

Significant leaks reduce available pressure at fixtures because water escapes before reaching taps.

Symptoms

Water bill has increased dramatically.

Pressure throughout the house is lower than normal.

You hear water running when no fixtures are on.

Water meter shows usage when all water is turned off.

Diagnosis

Turn off all water fixtures and appliances. Check the water meter.

If the meter is still turning or showing usage, you have leaks.

Check for obvious leaks under sinks, around toilets, and in visible pipe runs.

For hidden leaks, hire a plumber with electronic leak detection equipment. They can locate leaks without destructive investigation.

Solution

Repair all leaks. The cost depends on leak location and severity.

Accessible pipe leaks: $150-$400 per repair

Leaks in walls or slabs: $500-$2,000+ per repair

Once leaks are fixed, pressure should return to normal assuming no other problems exist.

Time required: Varies by leak location Cost: $150-$2,000+ per leak

Pressure Drop from Fixture to Fixture

Low pressure at a single fixture with normal pressure elsewhere indicates problems in that fixture's supply line or the fixture itself.

Diagnosis

Test pressure at the shutoff valve feeding the problem fixture. If pressure is normal at the valve but low at the fixture, the supply line or fixture has problems.

If pressure is low at the shutoff valve, the pipe feeding that valve has restrictions.

Solutions

Replace the supply line from the shutoff valve to the fixture. These flexible lines cost $8-$15 and install in 10 minutes.

Disassemble and clean the fixture. Mineral buildup inside faucet bodies can restrict flow even when the aerator is clean.

Replace the fixture if internal buildup is severe. New faucets cost $30-$300 depending on quality.

For low pressure at the shutoff valve, the branch line feeding that location has restrictions. This requires professional diagnosis and possible pipe replacement.

Time required: 30 minutes Cost: $8-$300

The Bottom Line on Low Water Pressure

Start with quick, free solutions: clean aerators, check shutoff valves, and verify your main valve is fully open. These solve 40% of pressure complaints in under 10 minutes.

If quick fixes don't work, test for whole-house versus localized problems. This determines whether you need system-wide solutions or targeted fixture repairs.

Pressure regulators and water softeners are common culprits when present. These require adjustment rather than replacement in many cases.

Old, corroded pipes in homes over 40 years old cause chronic pressure loss that only pipe replacement solves. If multiple symptoms point to pipe problems, get professional evaluation.

Most low pressure problems have solutions ranging from free to a few hundred dollars. Only severe pipe deterioration requires the $4,000-$12,000 investment of whole-house repiping.

Ignore low water pressure and it won't fix itself. Corroded pipes continue deteriorating, regulators fail completely, and leaks waste thousands in water costs. Address pressure problems promptly to prevent escalation to more expensive repairs.