The shower that used to sting now barely wets you. The kitchen faucet takes forever to fill a pot, and the hose outside has lost its reach. When pressure drops at one fixture, the cause is usually sitting in that fixture. When it drops everywhere at once, the cause is somewhere every fixture shares, which means upstream of the point where the pipes split off to each room.
That narrows the list a great deal. Whole-house pressure problems come down to a handful of things, and a few of them you can check before calling anybody.
Walk the house before deciding it is everywhere
Start by confirming the problem really is whole house. Go fixture by fixture and run cold, then hot. It takes a few minutes and it sorts the causes into separate piles.
If one faucet or one showerhead is weak and the rest are fine, look there first. Aerators and showerheads collect mineral scale and grit, and a cartridge inside a faucet can clog or wear. The small shutoff valve under a sink or behind a toilet may also be partly closed.
If only the hot side is weak, and it is weak everywhere, the problem is probably at or near the water heater: a partly closed valve on the heater, sediment, or a failing fitting on the hot outlet. Our water heater repair page for White Oak covers that side of the house.
If hot and cold are both weak at every fixture, the cause sits before the water heater and before the branches. One more check helps: ask a neighbor or two whether their pressure has dropped as well. If the whole street is weak, the issue is likely on the supply side, and you should check with your water provider before anybody starts looking at your pipes.
The valve that is only partly open
The least dramatic explanation is often the right one. The main shutoff valve for the house controls every drop that comes in, and if it is not fully open, every fixture feels it.
This happens more than people expect. A valve gets closed for a repair and opened only most of the way afterward. Somebody bumps it while working in the garage or the yard. On older houses the valve itself can fail inside, where the part that opens and closes breaks loose or corrodes and sits partway across the pipe no matter where the handle is turned. From the outside, the valve looks perfectly normal.
Some homes also have a pressure reducing valve near where the water line enters, a bell-shaped fitting that keeps incoming pressure at a steady level. When one of those wears out it can drift and cut pressure to the whole house, or fail the other way and let too much through. If your house has one and the change was fairly sudden, it belongs on the short list.
Check that the main valve is fully open. If it is an old valve that feels stiff, do not force it, since a seized valve that breaks in your hand turns a pressure complaint into a no-water call.
Water leaving before it reaches the house
A leak on the buried service line takes water away before any fixture sees it. A small leak may not change pressure much. A larger one, or an outright break, can drop pressure noticeably across the whole house, and it tends to arrive suddenly instead of creeping in over years.
The ground here gives these lines plenty of reasons to fail. When it rains, the clay takes on water and swells, and in a hot, dry summer it pulls back hard. A pipe buried in it gets moved with every change, and fittings and joints carry most of that strain.
A few signs travel with a service line leak: a patch of yard that stays soft or green when the rest has dried out, water collecting in the meter box, a water bill that has climbed without any change in how you use water. The meter can confirm it. With every fixture and appliance idle, a moving meter means water is going somewhere. Closing the main valve at the house and watching whether the meter stops tells you whether the loss is under the yard or indoors.
If that points to a leak, leak detection for White Oak homes is the next step, and a line that has broken outright is an emergency call.
Old pipe that has narrowed from the inside
Some whole-house pressure losses happen so gradually that nobody can say when they started. That pattern usually points at the pipe itself.
Galvanized steel supply lines, common in older houses around here, corrode from the inside. Rust and scale build on the inner wall year after year, and the opening water travels through gets smaller. The fixtures farthest from where the water comes in usually suffer first, and running two fixtures at once makes the drop obvious. A shower that loses most of its flow when someone opens the kitchen tap is a classic sign.
No valve adjustment or cleaning fixes that, because the restriction runs the length of the pipe. Eventually the practical answer is replacing the supply piping, which is what our repiping work covers.
Houses from the 1980s and 1990s bring a different material and a different story. Polybutylene does not usually narrow the way galvanized does. It tends to fail suddenly, and a sudden pressure drop in a house of that age is a reason to look for a leak before anything else. Whatever the age of the house, we look at what is actually in the walls and the yard before recommending anything that large.
What we check when we arrive
We start by measuring. A pressure gauge on an outdoor hose connection gives a number to work from, which is more useful than describing a shower as weak, and reading it with the main valve fully open rules that valve in or out quickly.
From there it is a process of elimination in a sensible order. We check the main valve and, if the house has one, the pressure reducing valve. We watch the meter with the house quiet to see whether water is leaving. We look at whatever pipe is visible, at the water heater connections and where the line enters the house, to see what material we are dealing with and what shape it is in.
Most of the time that sequence finds the cause in one visit. When it points to something bigger, like a buried leak that needs digging or an old system that needs replacing, we explain what we found and put a real price in front of you before any work begins. If we open something up and find a surprise, we stop and talk it through with you instead of adding it to the bill quietly.
And if the answer is that your whole street is low, we will tell you that too and point you back to the provider.
Questions about pressure dropping everywhere
My neighbors have low water pressure too. Is it my plumbing?
Probably not. When several houses on the same street lose pressure at the same time, the likeliest cause is on the supply side, and that is a question for your water provider. Check with them first. If their side turns out to be fine and your house is still weak after theirs recovers, then it is worth looking at your service line and valves.
Why did pressure drop right after a plumber worked on my house?
The two usual reasons are simple. A valve that was closed for the work may not have been opened all the way again. And shutting the water off and turning it back on can knock loose rust or scale that then lodges in aerators and valves. Check that the main valve is fully open and clean the aerators, then call if it is still low.
Does low pressure everywhere mean I need a repipe?
Sometimes, but it is rarely where we start. A partly closed or failed valve, a worn pressure reducing valve, or a leak on the service line all cause the same symptom and are much smaller repairs. We rule those out first. A repipe comes up when old galvanized has narrowed throughout the house, or when the same system keeps leaking.
Get a number, then a fix
If every tap in your house has gone weak, check the main valve and ask a neighbor, and if neither explains it, call 903-570-3051. You will reach Stephen, the Master Plumber who does the work, or you can send the details through our contact page. Our gallery shows service line jobs we have dug and finished, and the White Oak page lists the rest of what we take on around the area.