How to deal with low water pressure

This article is for educational purposes only and is not a substitute for professional advice. Local codes, regulations, and best practices vary by region.

The water coming out of your faucet is barely a trickle. Showers are pathetic. Washing your hands takes forever. Low water pressure makes everything in your house less pleasant, and it often has a simple cause. Sometimes it’s a problem with the city’s water supply. Sometimes it’s something in your house. Figuring out which one tells you whether you need to wait or fix something.

Low water pressure is usually fixable. The most common causes are mineral buildup in aerators, closed shut-off valves, or clogged supply lines. Most fixes are simple and inexpensive.

Is It Your House or the City?

First, determine if the problem is in your house or the city’s supply. Check with neighbors. If their pressure is fine, it’s your house. If multiple neighbors have low pressure, it’s a city issue. There’s nothing you can do about the latter except wait.

If only your house has low pressure, check if it’s everywhere or specific faucets. Low pressure in one bathroom but not another suggests a fixture problem. Low pressure everywhere suggests a whole-house problem.

Check the Shut-Off Valve

Every house has a main water shut-off where the supply enters. Sometimes this valve is partially closed, restricting flow. Check it under the sink, in the basement, or where the water line enters.

Look for a valve (usually near the water meter). Is it fully open? The handle should be inline with the pipe. If perpendicular, it’s closed. Turn it fully open (handle parallel to pipe) and test water pressure.

This single adjustment resolves many low-pressure issues.

Clean the Aerators

Faucet aerators are the mesh screens at the tip. Hard water minerals accumulate here, restricting flow. Unscrew the aerator (usually hand-tight or with a wrench). Soak it in white vinegar overnight. Use an old toothbrush to remove mineral deposits. Rinse thoroughly and screw it back.

This simple fix improves water pressure significantly. Cost is zero. Time is 10 minutes active time plus soaking time.

Check for Leaks

A hidden leak reduces water pressure. Check basements, attics, and crawlspaces for water stains or moisture. Look for wet spots in your yard or unusually green grass.

If you suspect a leak, contact a plumber for investigation. Hidden leaks are serious but repairs address them.

Water Pressure Regulator

Some houses have a pressure regulator (prevents pressure spikes). If it’s malfunctioning or set too low, it restricts flow. These are usually under the sink or where the line enters the house.

A pressure gauge (costs $10-20) measures water pressure. Normal is 40-80 PSI. Below 40 PSI indicates low pressure.

If a regulator is faulty, replacement is professional work. A plumber can replace it and set appropriate pressure.

Old Pipes and Mineral Buildup

Very old houses with galvanized steel pipes develop interior mineral and rust buildup over decades, restricting flow. This is common in homes over 50 years old.

Solutions include replacing the affected pipe sections or installing a whole-house water filter. These are professional jobs costing $500-2,000+ depending on extent.

A plumber can assess whether your pipes have buildup and recommend solutions.

Water Heater Issues

If only hot water pressure is low, the water heater might be the issue. Sediment accumulates in water heaters, restricting flow. Flushing the water heater (removing sediment) often improves hot water pressure.

Water heater flushing is professional work costing $100-300, or DIY if you’re comfortable with it.

Pressure-Reducing Valve Failure

Homes with high incoming pressure (over 80 PSI) often have a pressure-reducing valve that may fail. Malfunctioning valves restrict flow.

Testing pressure with a gauge determines if this is the issue. A plumber replaces the valve if needed (cost $200-400).

Temporary Solutions

Until you identify the problem, you can partially work around low pressure by using hot water first (it comes at higher pressure in some systems) or staggering water use.

These are temporary measures, not solutions.

When to Call a Plumber

If cleaning aerators and opening the shut-off valve don’t help, call a plumber. They can test pressure, inspect for leaks, and recommend solutions.

Plumber service calls cost $150-300 plus any repair costs. Most pressure issues are fixable.

The Bottom Line

Low water pressure is usually caused by mineral buildup in aerators, partially closed shut-off valves, or water pressure regulators. Start by checking the shut-off valve and cleaning aerators. These simple fixes resolve many problems. If pressure remains low, a plumber can diagnose and fix the issue. Low pressure is an inconvenience but usually manageable and fixable without major expense.

© The Whole Home Guide