How do I check my home's water pressure without special tools?

The simplest method is a pressure gauge that threads onto a standard outdoor hose bib — they're available at most hardware stores for under $15. Attach it to a hose bib, make sure no other water is running inside the house, and read the static pressure. Normal residential pressure runs between 40 and 80 psi. Anything below 40 psi is considered low and worth investigating; anything above 80 psi puts stress on fixtures and appliances.

Can low water pressure damage my appliances?

Chronically low pressure can cause problems for appliances that need a minimum flow rate to operate correctly — dishwashers, washing machines, and tankless water heaters all have minimum inlet pressure requirements listed in their manuals. A tankless water heater, for example, may fail to ignite or produce inconsistent hot water if inlet pressure falls too low. Check your appliance documentation for the minimum psi rating if you're experiencing performance issues alongside low pressure.

Why is my water pressure fine cold but drops when I run hot water?

This usually points to a restriction on the hot water side specifically — either inside the water heater itself (sediment buildup at the bottom of the tank can partially block the outlet) or in the hot water supply lines leading from the heater. If your water heater hasn't been flushed in several years, sediment accumulation is a likely contributor. A plumber can flush the tank and inspect the outlet connections to confirm whether the heater is the source.

My neighbor has great pressure but mine is low — could there be a leak between the meter and my house?

Yes, and this is one of the more common scenarios for a sudden or gradual whole-house pressure drop. The section of pipe between the water meter and your home's main shutoff — called the service line — is your responsibility as the homeowner, not the utility's. A leak anywhere along that run bleeds pressure before it ever reaches your fixtures. One way to check: turn off all water inside the house, then look at the meter. If the dial or digital display is still moving, water is flowing somewhere it shouldn't be.

Low Water Pressure in Your House? Here Are the Usual Suspects

Low water pressure in your house is almost never random. Behind that frustrating trickle from the kitchen faucet or the shower that takes forever to rinse shampoo out of your hair, there’s usually one of a handful of identifiable causes — and knowing which one you’re dealing with tells you whether this is a five-minute fix or a call to a plumber. Start by noticing the pattern: Is the pressure low everywhere, or just at one fixture? Has it dropped suddenly, or crept down over weeks? Those two questions alone will cut your suspect list in half.

The Most Common Culprits

A Partially Closed Shutoff Valve

If your pressure dropped noticeably after any recent work on your plumbing — a repair, a toilet replacement, a water heater swap — check the main shutoff valve first. It’s usually located where the water line enters the house, often near the water heater or in a utility closet. A ball valve (the lever type) should be parallel to the pipe when fully open. A gate valve (the round-handle type) needs to be turned fully counterclockwise until it stops. Even a quarter-turn in the wrong direction can cut flow noticeably. Check any secondary shutoffs under sinks or behind appliances too.

A Failing Pressure Regulator

Most homes in Corona and throughout Southern California have a pressure reducing valve (PRV) installed on the main line, typically near the meter or where the line enters the foundation. The PRV is set at the factory — usually somewhere between 45 and 80 psi — and it’s designed to protect your fixtures and appliances from the higher pressure in the municipal supply. When a PRV starts to fail, it can stick low and starve the whole house, or it can stick high and send pressure surging past what your fixtures are rated for. A sudden, whole-house pressure change with no other explanation is a strong sign the PRV needs adjustment or replacement.

Mineral Buildup Inside Pipes or Fixtures

Southern California water is notoriously hard. The water delivered across Riverside County carries dissolved calcium and magnesium that precipitate out as scale wherever flow slows down — inside older galvanized steel pipes, inside aerators, inside showerheads, and inside appliance inlet screens. If your low pressure is isolated to one fixture, unscrew the aerator (the small screen at the faucet tip) and look at it. White, chalky crust is scale. Soak it in white vinegar for an hour and reinstall it — if pressure recovers, you found the problem. If the same buildup is happening throughout the house, the issue is likely inside the pipes themselves. Galvanized steel pipe, common in Corona homes built before the mid-1970s, corrodes from the inside out over decades. The interior diameter narrows until flow is severely restricted. This is one situation where a plumber may recommend repiping rather than a series of partial repairs that keep recurring.

A Hidden Leak

Water that’s escaping through a crack, a corroded joint, or a pinhole leak never makes it to your fixtures — so the pressure at the tap drops. If you notice low pressure alongside any of these, a leak is the likely cause:

Water stains on ceilings or walls, even old ones
Soft or discolored spots on drywall
Unexplained wet patches in the yard, especially in dry weather
A water bill that’s higher than usual without a change in habits
The sound of running water when everything in the house is off

A slab leak — a leak in the pipes embedded in your concrete foundation — is particularly common in older Inland Empire homes because of soil movement and the age of the copper lines. Slab leaks can run for a long time before they surface visibly, silently bleeding pressure and driving up your bill. Professional leak detection uses acoustic listening equipment and thermal imaging to locate the break without opening walls or cutting concrete until the exact location is confirmed.

Municipal Supply Pressure or Demand

Occasionally the problem isn’t in your house at all. If neighbors are reporting the same issue, or if your pressure is consistently low only during peak morning and evening hours, the municipal supply pressure may be the variable. You can check your street-side pressure with an inexpensive gauge that threads onto an outdoor hose bib. If it reads below 40 psi, the supply side is the starting point for the conversation — contact your water utility. If it reads normal and your indoor pressure is still low, the restriction is somewhere inside your property.

What NOT to Do

Don’t crank open a gate valve fast. Opening a gate valve too quickly after it’s been partially closed can dislodge scale and debris that then plugs aerators and appliance filters downstream.
Don’t ignore a sudden whole-house pressure drop. A slow decline over months is usually buildup or a regulator aging out. A sudden drop is more likely a leak or a valve failure — both of which get worse, not better, with time.
Don’t assume a pressure booster pump is the solution. Adding a booster pump on top of a leak just moves more water out of the hole faster. Diagnose first.
Don’t use chemical drain openers to address mineral buildup in pipes. They’re formulated for organic clogs and won’t dissolve calcium scale. They can also damage older pipe materials.

When to Call a Plumber

Some pressure problems are genuinely DIY-friendly — cleaning an aerator, reopening a shutoff valve, or adjusting a PRV if you’re comfortable with basic plumbing. But call a professional when:

Pressure is low throughout the entire house and you’ve confirmed the shutoff valves are fully open.
You suspect a leak but can’t locate it — especially if it might be under the slab.
The pipes in your home are galvanized steel and the buildup is systemic rather than isolated to one fixture.
You’ve replaced the PRV before and it’s failing again, which can indicate a water quality or pressure spike issue worth diagnosing at the source.
Your water bill has climbed without explanation.

For homes in Corona with older plumbing, the honest answer is sometimes that a series of targeted repairs will cost more over five years than addressing the root cause — whether that’s a PRV replacement, targeted pipe replacement, or a full repipe of the galvanized lines.

The Longer Fix: Repiping and What It Involves

If your home has galvanized steel supply lines and you’re seeing chronic low pressure, discolored water, or recurring leaks at joints, repiping is worth understanding even if you’re not ready to schedule it today. Modern repipes typically use copper or cross-linked polyethylene (PEX) tubing. PEX is flexible, resistant to scale buildup, and easier to route through finished walls than rigid pipe, which reduces the drywall repair needed afterward. A full repipe on a typical single-story house is usually completed in one to two days. Water is restored the same day the work is done.

The process starts with a plumber mapping your existing supply lines, identifying which sections are galvanized versus already-updated copper, and giving you a scope of work. You don’t have to repipe the entire house at once — it’s common to prioritize the sections causing the most problems.

If you’ve worked through the checklist above and still can’t pin down why your pressure is low — or if you’ve found a likely culprit but aren’t sure how serious it is — RT Olson Plumbing, Heating and Air Conditioning serves Corona and the surrounding area and can help diagnose what’s actually happening inside your pipes. Reach them at (951) 344-5596.