Why Your Water Pressure Dropped — and How to Get It Back

Weak pressure is one of the most common calls we get, and it's one of the few plumbing problems you can meaningfully diagnose yourself before anyone shows up. The trick is answering the right questions in the right order.

Start here: two questions that split the whole problem

Before you touch a tool, answer these:

1. 1Is it one fixture, or the whole house? Walk around. Run the kitchen sink, a bathroom sink, a shower, the laundry tap. Is everything weak, or is it just that one shower you've been complaining about?
2. 2Is it hot only, cold only, or both? At a fixture that's weak, run each side separately. Hot weak but cold strong is a completely different problem than both being weak.

Those two answers eliminate about eighty percent of the possible causes. Everything below is organized around them.

One fixture only

Good news — this is almost always local, cheap, and fixable in an afternoon.

• Clogged aerator. The little screen screwed into the tip of the faucet. Unscrew it, and you'll usually find grit, mineral flakes, and bits of rubber. Soak it in vinegar, rinse it, reinstall. Do this first, every time. It solves more pressure complaints than anything else on this list.
• Scaled-up shower head. Same story. Mineral deposits close down the spray holes. Unscrew it and soak it, or replace it — they're consumable.
• Failing cartridge or valve. If a single-handle faucet or shower valve is weak on both sides and the aerator is clean, the cartridge is likely worn, scaled, or partially blocked. That's a part swap.
• A partially closed angle stop. The little shutoff under the sink or behind the toilet. Somebody bumped it, or it was never fully opened after the last repair, or it's an old multi-turn stop that's crudded up internally and no longer opens all the way.
• A kinked or crushed supply line, especially behind a vanity or under a sink where someone shoved a bucket in there.

Hot side only, everywhere in the house

If cold is strong at every fixture and hot is weak at every fixture, the problem is at or near the water heater. Three usual suspects:

• The shutoff valve on the heater isn't fully open. Very common after any service. Check it.
• Sediment. Years of mineral fallout collects in the bottom of the tank and starts choking the outlet. Flushing the tank may help; on a badly neglected old unit, it may be too late.
• A collapsed or broken dip tube. The dip tube carries incoming cold to the bottom of the tank. When it deteriorates, it can shed plastic fragments that travel down the hot lines and lodge in aerators and cartridges all over the house. Classic tell: you clean an aerator, find white plastic bits, and the same thing happens at three other fixtures a month later.

The whole house is weak

Now we're upstream of everything, and the list is shorter but the stakes are higher.

The pressure-reducing valve

Most homes on municipal water have a pressure-reducing valve — a PRV — usually a bell-shaped brass fitting near where the main line enters the house or right after the meter. Street pressure is often far higher than a house should see, and the PRV knocks it down to something your fixtures and appliances can live with.

PRVs are mechanical. They have a spring and a diaphragm. They wear out. When one starts failing it usually fails one of two ways: it clamps down and starves the house, or it stops regulating and lets full street pressure through. Both are problems. If your whole house went weak over the course of a few months and nothing else changed, the PRV is the first thing a technician will look at.

The other whole-house causes

• Main shutoff not fully open. Someone worked on the house, closed the main, and reopened it three-quarters of the way. It happens constantly.
• Galvanized steel pipe. In older homes — and there are plenty around downtown Newnan and Senoia — galvanized supply lines corrode from the inside. The rust builds inward until the usable diameter is a fraction of what it was. There is no cleaning that out. The fix is repiping.
• A leak. Water escaping before it gets to your fixtures is water that isn't pressurizing them. Run the meter test: shut everything off, watch the low-flow indicator at the meter. If it's turning, you have a leak, and pressure is a symptom, not the disease.
• The utility side. Sometimes it's just not you. A main break, hydrant work, or a change on the municipal side can drop pressure in a whole neighborhood. Ask a neighbor before you spend money.

Measure it. Don't guess it.

Buy a water pressure gauge from any hardware store. It's an inexpensive brass gauge with a female hose thread. Screw it onto an outside hose bib — ideally the one closest to where the main enters — and open the valve all the way.

Take two readings: one static (nothing else running in the house) and one dynamic (with a tub and a couple of faucets running). Residential water pressure is measured in psi, and typical residential systems are designed to operate in a moderate psi band — well below street pressure. If your static reading is far below that band, you have a restriction. If it's well above it, you have a different problem entirely.

On a well? Different animal

Plenty of homes out toward Sharpsburg and Senoia are on private wells, and pressure works differently there. You have a pressure tank with an air bladder and a pressure switch that tells the pump when to kick on and off. Weak or surging pressure on a well usually means one of these:

• Waterlogged pressure tank — the bladder failed, so the tank has no air cushion and the pump short-cycles on and off rapidly. You'll hear it.
• Pressure switch out of adjustment or pitted contacts — the cut-in and cut-out points have drifted.
• A failing pump or a clogged well screen — pressure builds slowly and never quite gets there.
• A clogged sediment filter or iron filter — extremely common on well systems and easy to overlook. Check the filter before you condemn the pump.

Let's get your pressure back

If you've cleaned the aerators, checked the valves, and it's still weak — or the gauge is reading somewhere it shouldn't — that's where we come in. Wright Way Services diagnoses pressure problems, replaces PRVs, and repipes homes across Newnan, Peachtree City, and the rest of Coweta County. Reach us any time at (770) 301-4638.