Polly Plumbing | 1762 Keller Pkwy, Keller, TX | (817) 286-3446. Written by Haven Brady, Co-Founder. Locally owned, not a franchise. Every diagnosis on our trucks gets reviewed by a licensed master plumber. Texas License RMP-42199. Serving Keller, Southlake, North Richland Hills, Grapevine, Flower Mound, Fort Worth, Arlington, Trophy Club, Roanoke, and all of Tarrant County.
The third cartridge is usually the tell.
Somebody replaces the cartridge in a leaky bathroom faucet. It works for a while, then drips again, so they replace it again. By the third one they are cursing the manufacturer, or the hardware store, or their own handiwork. None of those are the problem. Something upstream is pushing harder than the fixture was built to take, and it will eat the fourth cartridge too.
High water pressure is the quietest expensive problem in a house. It never announces itself. It just shortens the life of everything it touches, and every failure it causes looks like an unrelated, ordinary failure. A flapper here. A drip there. A water heater that gave up early. A pinhole in a supply line at two in the morning. Homeowners fix each one separately, one small bill at a time, and never meet the cause.
The good news is that it is one of the few plumbing problems you can diagnose yourself, completely, in about five minutes, with a tool that costs less than a pizza. This article shows you how, explains the one number that decides everything, covers the part of the system nobody has ever looked at, and tells you honestly which of these symptoms is usually nothing.
The Number Your House Is Built Around
Every fixture, valve, seal, and appliance in your home is engineered for a pressure range. Miss it on the high side and everything wears fast.
Plumbing code sets the ceiling at 80 psi. Above that, code requires a pressure reducing valve, and the reason is not bureaucratic caution: past 80, the stress on joints, seals, and valve seats stops being theoretical. Most homes live comfortably between 40 and 80. The genuine sweet spot, strong showers and long-lived parts, is roughly 50 to 60.
What high pressure does is simple and relentless. It holds every seal in your house under more force than it was designed for, every hour of every day. Rubber compresses and hardens faster. Valve seats wear. Joints that would have been fine for thirty years get worked a little harder for ten. Nothing dramatic happens, which is exactly the problem, because a house at 95 psi feels great in the shower while it quietly runs down the clock on every part inside the walls.
Numbers past about 100 psi deserve prompt attention, since that is territory where supply lines and connections can fail outright rather than gradually.
The Problems High Pressure Gets Blamed For
Here is the honest symptom list, written the way these actually show up, because almost every one of them gets attributed to something else first.
Faucet cartridges and shower valves that keep failing. The opening story. Parts that should last years start lasting months, and the repair keeps coming back.
Toilet flappers dying young. Flappers are rubber holding back pressurized water. Push harder, they wear sooner, and you get a toilet that runs again a year after you fixed it. Our rebuild or replace a toilet guide covers the part swaps, but repeat failures point upstream.
Banging pipes. Water hammer, that thump when a washing machine or dishwasher valve snaps shut, gets worse as pressure climbs, because you are stopping a harder-moving column of water. Not every bang is pressure, but pressure makes every bang louder.
Faucets that splash and blast. A tap that sprays out of the sink at a quarter turn is not a great water heater. It is a warning.
A water heater relief valve that weeps. The temperature and pressure relief valve on your water heater is a safety device doing its job when it discharges. If it dribbles regularly, something is pushing the system past its limit, and that is worth understanding rather than capping. More on this below, since it has its own twist.
Drips and small leaks that keep returning anywhere in the house. One fixture failing is a fixture. Three unrelated fixtures failing in a year is a system.
A water heater that failed sooner than it should have. Constant excess pressure is hard on a tank that is already fighting our hard water, which is a real factor in the local lifespan numbers our guide to replacing a water heater before it fails walks through.
Any one of these alone is just a repair. Two or three together in the same house is pressure until proven otherwise.
Test It Yourself in Five Minutes
This is the rare plumbing question a homeowner can answer completely without us, and we would rather you knew the number.
Buy a water pressure gauge at any hardware store. It is a small round dial with a female hose thread, and it costs less than lunch. It may be the single most useful plumbing tool a homeowner can own. Thread it onto an outdoor hose bib, snug by hand, and open the faucet all the way. Read the needle. That is your static pressure.
Two rules for an honest reading. Test with nothing else running, no irrigation, no laundry, no dishwasher, because water moving anywhere in the house drags the number down and can hide a high reading. And test at an outdoor spigot or the laundry connection, not a kitchen sink, since aerators and fixture valves distort the result.
Now the trick most people never hear. Municipal pressure is not constant. It climbs at night when everyone stops using water. So a house that reads a comfortable 72 psi at noon can be sitting at 95 at three in the morning, silently working on every seal while you sleep. The fix is to buy the version of the gauge with a second needle, sometimes called a lazy hand or maximum pointer. It stays parked at the highest pressure the gauge has seen until you reset it. Thread that gauge on, leave it overnight, and read it with your coffee. You now know your true peak, not your convenient one, and peak is what breaks things.
Write the number and the date on a piece of tape and stick it on the pipe near your main shutoff. In three years, when you test again, that scrap of tape turns a single reading into a trend. A pressure that has climbed ten psi above your old baseline is telling you something is changing, even if you are still under 80.
Why Your Number Is Not Your Neighbor’s
Two houses on nearby streets can have genuinely different pressure, and the reason is gravity.
Municipal water systems get their pressure largely from elevation: water stored high, distributed downhill. The lower your house sits relative to the tank or tower serving your zone, the more pressure arrives at your meter, at roughly half a psi for every foot of elevation difference. Twenty feet lower than the neighborhood up the hill is a meaningfully different number at your hose bib. Homes at the low end of a pressure zone can see readings north of 100 psi with nothing at all wrong in the system.
Around here that means the answer is genuinely local, street by street, and it is why we do not guess. It also means a newer home is not automatically safe. Plenty of houses were built with a pressure reducing valve precisely because the street demanded one, and that valve has been quietly aging ever since.
Polly Plumbing is a locally owned shop on Keller Parkway. We test pressure, replace failing PRVs, and fix what high pressure has been breaking, across Keller and Tarrant County, with everything in writing.
The Twist: Your Water Heater Adds Pressure Too
Here is the part that explains the weeping relief valve, and it is the piece most homeowners have never been told.
Water expands when you heat it. In an open system, that extra volume simply pushes back toward the street and nothing happens. But most modern homes are closed systems, because the pressure reducing valve or a check valve at the meter only lets water flow one direction. So when your water heater fires and the water inside expands, that expansion has nowhere to go. Pressure in the house climbs, sometimes sharply, every heating cycle. It is called thermal expansion, and it is why a house can test fine in the afternoon and still be spiking hard every time the tank runs.
The designed answer is an expansion tank: a small tank, usually mounted near the water heater, with a cushion of air inside that absorbs the extra volume. That is why it appears on honest water heater installation quotes as a code item, which our water heater installation cost guide itemizes. It is not padding. It is the part that keeps every heating cycle from becoming a pressure spike.
Two things go wrong with them. Some houses never got one. Usually a pressure reducing valve or check valve was added years after the home was built, quietly turning an open system into a closed one with no cushion anywhere. And expansion tanks themselves fail: the internal bladder gives out, the air charge is gone, and the tank becomes a heavy decoration. A quick field check, tap the top and the bottom of the tank, the top should sound hollow and the bottom solid. All solid usually means it is waterlogged and no longer doing anything.
So when a relief valve weeps, the honest sequence is: test the pressure, check whether the system is closed, and check whether the expansion tank exists and still works. What that valve is never doing is malfunctioning for fun. It is reporting. Our water heater leaking guide covers which drips mean what.
Meet the PRV, the Part Nobody Has Ever Looked At
If your pressure reads high, the fix lives at one specific part, and most people do not know whether they even have one.
A pressure reducing valve is a bell-shaped brass fitting on the main line, generally right where water enters the home. Look near the main shutoff, in a garage, a utility area, or a box near the front of the house. It takes whatever the street sends and steps it down to something your plumbing can live with. Many local homes have one. Many owners have never noticed it.
The important thing to know is that PRVs wear out, typically over a span of years rather than decades, and they fail in two opposite ways. A PRV can fail open, passing full street pressure straight into the house, and that is the failure that starts killing cartridges and flappers. Or it can fail partially closed, choking flow, which shows up as weak pressure everywhere, the exact complaint our low water pressure guide for Keller TX addresses. Same part, opposite symptoms.
Some PRVs have an adjustment screw, and it is fair to ask whether you can simply turn it. Sometimes, if the valve is healthy and only needs dialing in. But if adjusting produces no change in the gauge reading, the valve is done internally and adjusting harder accomplishes nothing. Replacement ties into the main water line, needs the right sizing and setting, and gets verified with a gauge afterward. That is why it lands on our side of the line rather than yours. It is routine work, not a big project, and it protects everything downstream of it at once.
What Is Actually Fine
Now the part that talks you out of a panic, because not everything on the symptom list means your house is under siege.
A satisfying, strong shower is not evidence of a problem. Plenty of houses run a healthy 60 to 70 psi and feel great, and the goal here was never a weak trickle. One occasional thump from the washing machine is ordinary, especially in a house with long pipe runs, and it does not by itself mean anything is wrong. A relief valve that discharged once after an unusually hot cycle is worth watching rather than panicking over; a valve that weeps regularly is the one that has something to say. And a single failed faucet cartridge is just a part that reached the end of its life, which happens.
The pattern is what matters. Repeat failures across different fixtures, plus a gauge reading over 80, is a real finding. One drip and a normal number is a Tuesday.
Test first. The gauge settles this cheaply and fast, and it keeps you from replacing a PRV you did not need.
What It Costs, the Short Honest Version
The diagnosis end of this is genuinely inexpensive, which is why we push the do-it-yourself gauge so hard: for the price of a sandwich you can rule the whole thing in or out. If the number comes back high, a PRV replacement is a routine, modestly priced job on our board, well under big-ticket work like slab or line repair. It is one of the better returns in plumbing, because it stops you paying for repeat fixture failures. Adding an expansion tank where a closed system needs one is likewise a small job. What all of it protects is much more expensive: water heaters, supply lines, and the pinhole leak you never want to meet at 2 a.m. As always, the written quote is the invoice, the $89 dispatch fee is waived for PollyCare members, and there is no emergency surcharge.
Write the Number on the Pipe
Here is the whole article as a habit worth keeping.
Buy the gauge with the second needle. Test on a quiet morning, then leave it overnight once and read the peak. Write both numbers and the date on tape stuck near your main shutoff. Retest every couple of years, or any time fixtures start failing in a pattern, and compare against that tape. Under 80 with no repeat failures means go enjoy your day. Over 80, or climbing steadily against your own baseline, means the PRV deserves attention. Fix it before it collects another cartridge, another flapper, and eventually something that costs real money. It is the cheapest preventive check in the whole house, and almost nobody does it.
We Are Close By
Polly Plumbing tests water pressure, replaces failing PRVs, and installs expansion tanks from our shop on Keller Parkway, serving Keller, Southlake, North Richland Hills, Flower Mound, Fort Worth, Arlington, Trophy Club, Roanoke, and all of Tarrant County.
Gauge reading over 80, or fixtures failing on repeat? That is fixable at one part. Call (817) 286-3446. Live agents answer 24/7, we verify the pressure before and after, and the written quote is the invoice.
Frequently Asked Questions About High Water Pressure
What should my home water pressure be?
Most homes run safely between 40 and 80 psi, and the sweet spot is roughly 50 to 60, strong enough for good showers without grinding down seals and valves. Plumbing code sets 80 psi as the ceiling and requires a pressure reducing valve above it, because past that point the constant stress on joints, seals, and valve seats becomes a real risk. Readings over 100 psi deserve prompt attention, since that is where supply lines and connections can fail outright rather than gradually. A hardware store gauge answers this in five minutes. Call Polly Plumbing at (817) 286-3446.
How do I test my water pressure at home?
Buy an inexpensive water pressure gauge with hose threads, screw it onto an outdoor hose bib or the laundry connection, and open the faucet fully. Make sure nothing else is running, since any water use elsewhere drags the reading down and can hide a high number. Test an outdoor spigot rather than a kitchen sink, because aerators and fixture valves distort the result. For the most useful version, buy a gauge with a second maximum pointer needle and leave it on overnight, since municipal pressure climbs when demand drops. Call Polly Plumbing at (817) 286-3446 if it reads high.
What are the signs of high water pressure?
Faucet cartridges and shower valves that fail repeatedly. Toilet flappers that wear out early. Banging pipes when appliance valves close, and faucets that splash and blast. A water heater relief valve that weeps regularly. Small leaks that keep returning at different fixtures, and a water heater that failed sooner than expected. Any one of those alone is just a repair. Two or three together in the same house point at pressure as the shared cause, and a gauge reading over 80 psi confirms it. Call Polly Plumbing at (817) 286-3446.
Why does my water heater relief valve drip?
Usually because system pressure is exceeding the valve’s limit, and the valve is doing its safety job by discharging. Most modern homes are closed systems, where a pressure reducing valve or check valve prevents water from flowing back toward the street. So when the heater fires and water expands, that expansion has nowhere to go and pressure spikes. The designed fix is an expansion tank near the heater to absorb it, and those either were never installed or have failed internally. Never cap a relief valve; find out what it is reporting. Call Polly Plumbing at (817) 286-3446.
What is a PRV and how long does it last?
A pressure reducing valve is a bell-shaped brass fitting on the main line, usually where water enters the home near the main shutoff, that steps street pressure down to something the plumbing can live with. They wear out over a span of years, and they fail in two opposite ways. Failing open passes full street pressure into the house and starts destroying fixtures. Failing partially closed chokes flow and looks like a low pressure problem. If adjusting the screw changes nothing on the gauge, the valve is finished internally. Call Polly Plumbing at (817) 286-3446.
Can high water pressure really damage my plumbing?
Yes, though slowly enough that people rarely connect the failures to the cause. Excess pressure holds every seal, joint, and valve seat in the house under more force than it was designed for, around the clock, so rubber hardens faster, valve seats wear, and joints get worked harder than intended. The result is not one dramatic event but a stream of ordinary-looking repairs: cartridges, flappers, small leaks, and a water heater that quits early. Correcting the pressure protects the entire system at once. Call Polly Plumbing at (817) 286-3446.
Why is my water pressure higher at night?
Because municipal pressure rises when neighborhood demand falls. All day, water use across the system holds pressure down; late at night, when irrigation stops and households go quiet, that same supply pushes harder into every house on the line. A home that reads a comfortable number at noon can be considerably higher at three in the morning, stressing seals for hours with nobody awake to notice. That is exactly why a gauge with a maximum pointer, left on overnight, gives a truer picture than a daytime spot check. Call Polly Plumbing at (817) 286-3446.