What's Causing Low Water Pressure in My Johnston Home?

Weak showers. A washing machine that takes twenty minutes to fill. The toilet tank that won't refill before the next flush. If your Johnston home has developed low water pressure, you're not imagining things — and the cause is almost always one of a handful of common culprits.

Here's how we diagnose it at Kwik Plumbing & Heating, and what you can check yourself before calling us.

Step one: is it everywhere or just one spot?

Before anything else, figure out whether the pressure is low everywhere in the house or just at one fixture. That one question eliminates half the possible causes.

If it's only at one fixture

You're probably dealing with a localized problem:

• Clogged aerator. Unscrew it from the faucet spout, rinse out any sediment, and reinstall. This is the most common fix, and it takes two minutes.
• Clogged showerhead. Soak it in white vinegar overnight or replace it.
• Partially closed stop valve under the sink or behind the toilet.
• Failing cartridge in a single-handle faucet.
• Kinked braided supply line behind the appliance.

If it's the whole house

Now we're looking at the supply side. Several things can cause it.

The usual suspects

1. A failing pressure-reducing valve (PRV)

Most Rhode Island homes have a PRV where the water line enters the basement. It protects your plumbing from excessive street pressure. The bad news: PRVs wear out internally and slowly drift lower over 10–15 years. If your pressure has dropped gradually over months and you haven't changed anything, a failing PRV is the leading suspect. Replacement is usually in the $250–$500 range for the part and labor.

2. A partially closed main shutoff

Sometimes someone turned the main valve during a repair and forgot to fully reopen it. Check the main valve where the water line enters your house — it should be all the way open.

3. Corroded galvanized pipes

Older Johnston homes (pre-1960s) often still have galvanized steel supply piping. Over decades, the inside of those pipes scales up like plaque in an artery. Even with strong street pressure, you can barely get water through them. The permanent fix is a repipe to copper or PEX — a bigger project, but it pays for itself in every shower you take afterward.

4. A hidden leak

If pressure dropped suddenly with no obvious cause, check for a hidden leak. Warning signs: a jump in your water bill, soggy spots in the yard, unexplained puddles in the basement, or the sound of running water when everything is off. Underground service line leaks are serious — call us the same day.

5. Municipal issues

Providence Water does occasional maintenance and main work that temporarily drops pressure. Usually it resolves within a few hours. If your neighbors are also affected, check the utility's website before calling a plumber.

6. A clogged whole-house filter

If you have a sediment filter or softener installed, a neglected cartridge can choke the flow to the entire house. Easy fix, often missed.

How we diagnose it

A real diagnosis starts with a pressure gauge. We thread a gauge onto an outdoor hose bib or laundry bib and read the static pressure. Normal residential pressure is 40–80 psi, with the sweet spot around 50–60. We also test dynamic pressure while a tub tap is running — that tells us whether the supply can actually deliver flow, not just sit there looking pretty. If you have a PRV, we test before and after it to see if the valve is the bottleneck.

When to call us

Call Kwik Plumbing & Heating during our regular business hours if:

• Pressure dropped suddenly with no explanation
• You've cleaned the aerators and the fixture is still weak
• Your PRV is more than 10 years old
• Whole-house pressure is under 40 psi

We'll bring the gauges, find the bottleneck, and give you an honest answer on how to fix it.