What is the first low-pressure check?

Confirm that the main valve and fixture shutoffs are fully open, then clean aerators and showerheads. If only one fixture is affected, the problem is usually local.

When should you avoid simply raising pressure?

Do not raise pressure to mask leaks, failing fixtures, old piping, or a bad regulator. Excessive pressure can damage valves, appliances, and supply lines.

How to Increase Water Pressure in Your Home

Low water pressure is one of the most frustrating plumbing problems. A weak trickle from your shower, slow-filling washing machine, or feeble garden hose can make everyday tasks take twice as long. The fix depends on what’s causing the low pressure — and many causes have straightforward DIY solutions.

Normal household water pressure is 40–80 PSI. Below 40 PSI is considered low; above 80 PSI can damage pipes and appliances.

Step 1: Test Your Current Water Pressure

Before diagnosing the cause, measure your actual pressure with a pressure gauge. Attach a water pressure gauge to an outdoor spigot or laundry room faucet, turn the water fully on, and read the dial.

Below 40 PSI: Low pressure confirmed — work through the causes below
40–80 PSI: Pressure is normal — the problem may be localized (clogged aerator, etc.)
Above 80 PSI: High pressure — you need a pressure reducing valve, not an increase

Common Causes of Low Water Pressure

1. Clogged Aerators and Showerheads

The most common cause of low pressure at a single fixture is a clogged aerator or showerhead screen. Mineral deposits from hard water restrict flow over time.

Fix:

Remove the aerator from the faucet spout (unscrew by hand or with pliers)
Soak in white vinegar for 1–2 hours
Scrub with a small brush and rinse
Reinstall

For showerheads, unscrew the head and soak it in a bag of vinegar overnight. If your showerhead is old, replacing it with a high-efficiency showerhead designed for low-pressure systems can improve flow noticeably.

2. Partially Closed Shutoff Valves

There are two main shutoff valves that affect whole-house pressure:

The main shutoff valve: usually located where the water line enters your home (near the water meter, in the basement, or in a utility closet)
The meter valve: at the water meter box outside, controlled by the utility company

Check that your main shutoff is fully open. A valve that’s only partially open significantly reduces pressure. Ball valves should be turned so the handle is parallel to the pipe; gate valves (with a round wheel handle) should be fully counterclockwise.

3. Pressure Reducing Valve (PRV) Needs Adjustment or Replacement

Most homes built after the 1980s have a PRV — a bell-shaped fitting where the main supply line enters the house. PRVs reduce municipal pressure to a household-safe level, but they can be adjusted or fail over time.

Adjusting the PRV:

Loosen the lock nut on the adjustment screw
Turn the screw clockwise to increase pressure
Test with a gauge and aim for 50–60 PSI
Retighten the lock nut

If adjusting doesn’t help or the PRV is old, replace it. A Watts water pressure reducing valve runs $30–$60 and is the industry standard for residential use.

4. Old Steel or Galvanized Pipes

Galvanized steel pipes common in pre-1960s homes corrode from the inside, gradually narrowing the pipe interior and reducing flow. If your home has original galvanized plumbing, low pressure and rusty water are signs the pipes have significantly corroded.

Fix: Repipe with copper or PEX — a job for a licensed plumber.

5. Leaks in the System

A leak reduces pressure throughout the system. Signs of a leak include:

Water meter moving when all fixtures are off
Damp spots on walls, ceilings, or floors
Unexplained increase in water bills
Sound of running water in the walls

Shut off all water in the house and check whether your water meter dial is still moving. If it is, you have an active leak.

6. Shared Supply Line Issues

If you’re on a municipal water supply, low pressure during peak hours (mornings and evenings) may be a provider-side issue. Contact your water utility to ask about pressure levels at the meter.

If neighbor’s pressure is fine but yours isn’t, the problem is definitely in your house’s plumbing.

7. Hot Water Pressure Only

If you have low pressure only on the hot water side, the water heater may be the culprit:

Check that the hot water shutoff valve at the heater is fully open
Sediment buildup in the tank can restrict flow — flush the tank (see our water heater maintenance guide)
A partially closed or malfunctioning water heater shutoff valve is a common cause

Installing a Pressure Booster Pump

If your incoming water pressure from the utility is genuinely low (confirmed at the meter), a pressure booster pump can increase pressure throughout the house.

These systems install on the main supply line and boost pressure by 50 PSI or more. They’re most common in multi-story homes where upper floors see reduced pressure, and in areas with chronically low municipal supply pressure.

Booster pump installation is typically a job for a licensed plumber, as it involves soldering or press-fit connections on the main line.

Pressure Reading Guide

Static pressure reading	What it usually means
Under 40 PSI	Low supply pressure or a restriction worth investigating
40-60 PSI	Normal for many homes
60-80 PSI	Strong but generally acceptable
Over 80 PSI	Too high for many plumbing systems; check the pressure reducing valve

Do not solve weak flow by blindly increasing pressure. High pressure can shorten the life of supply lines, toilet fill valves, water heater components, and appliance hoses. If the gauge shows normal static pressure but fixtures still feel weak, the issue is more likely flow restriction: clogged aerators, undersized piping, a failing cartridge, scale, or a partially closed valve.

Before You Buy a Booster Pump

Test pressure at an outdoor hose bib and at a laundry connection if possible
Ask neighbors whether they have the same issue
Confirm the main shutoff and meter valves are fully open
Check whether a pressure reducing valve is stuck or misadjusted
Inspect for leaks before adding pressure to the system

A booster pump is a last step after measurement, not the first purchase.

If pressure changes suddenly, treat it as a diagnostic problem, not a comfort upgrade. Sudden drops can point to a leak, failed valve, utility work, or debris that broke loose and clogged a fixture.

Conclusion

Low water pressure is usually caused by something simple: a clogged aerator, a partially closed valve, or a PRV that needs adjustment. Start by testing your pressure with a gauge, then work through the checklist from the easiest fix first. If the problem is systemic (old pipes or genuinely low supply pressure), a plumber can assess whether repipe or a booster pump is the right solution.