Is 100 PSI Water Pressure Too High? Warning Signs, Causes & How to Fix It

When people talk about water pressure problems, they usually mean pressure that’s too low: water that dribbles from faucets or takes forever to fill a bucket. The opposite problem, water pressure that’s too high, is just as common and much easier to miss, even though it does more damage to a home’s plumbing over time. This guide covers what counts as too high, the specific psi numbers homeowners search for most (100, 110, 120, and 150 psi), the damage high pressure causes, how to check your own water pressure, and how a licensed plumber fixes it for good. 

What Counts as Too High Water Pressure? 

For most homes, 40 to 80 psi (pounds per square inch) is the normal, safe range, with 80 psi generally treated as the practical ceiling. Anything consistently at or above 100 psi is too high. Here is what the most commonly searched numbers actually mean: 

1. 40 to 60 psi: normal, comfortable range for most fixtures and appliances. 
2. 60 to 80 psi: still normal; many plumbing codes treat 80 psi as the upper limit before a regulator is required. 
3. 100 psi: too high. This is the number homeowners hit most often when they test their own water pressure, and it is above the level most manufacturers rate residential plumbing and appliances for. 
4. 110 to 120 psi: too high, and common in homes on municipal systems with older or oversized distribution pumps. 
5. 150 psi or higher: some municipal water companies run pressure this high to keep enough force available for fire hydrants and tall commercial buildings; homes on these systems almost always need a regulator. 

Why High Water Pressure Damages Your Home 

High water pressure is usually not something a homeowner causes. It is typically the municipal water company’s doing, since utilities often set pressure higher than any single house needs in order to guarantee adequate flow for fire hydrants and taller buildings elsewhere on the same system. Whatever the source, sustained pressure above 80 psi puts constant stress on pipes, fittings, and every water-using appliance in the house. 

1. Dripping or leaking faucets, even ones that are fully shut off 
2. Banging or knocking pipes (water hammer) when a faucet or valve closes quickly 
3. Shortened lifespan for water heaters, dishwashers, and washing machines 
4. Leaking supply lines and fittings that would otherwise last for years 
5. Higher water bills from the added leaks and waste that high pressure causes 

Signs Your Home Has High Water Pressure and How to Test It 

Because high pressure builds up slowly, most homeowners do not notice it until something fails. The good news is that confirming it takes about five minutes and a ten dollar gauge. 

1. Watch for faucets that drip a little even when fully closed 
2. Listen for banging or knocking pipes right after a faucet, washing machine, or toilet valve shuts off 
3. Check appliance supply hoses and fittings for early wear, bulging, or small leaks 
4. Notice if your water heater, dishwasher, or washing machine is failing years earlier than expected 
5. Screw a hose bib pressure gauge onto an outdoor spigot or a washing machine connection, turn the water on fully, and read the psi directly off the gauge 

How to Fix High Water Pressure 

Since the source of the problem is usually the municipal supply, homeowners cannot lower it at the source, but a licensed plumber can control it at the point where water enters the house. 

1. Have a plumber test your incoming water pressure with a calibrated gauge rather than relying on a single DIY reading 
2. Install a pressure reducing valve (PRV) on the main line, set to bring incoming pressure down to the 60 to 80 psi range 
3. Have the PRV checked periodically. PRVs are mechanical and can fail or drift out of adjustment over several years, quietly letting pressure creep back up 
4. Add water hammer arrestors near washing machines and other quick-closing valves if banging persists after the PRV is installed 
5. Avoid adjusting an existing PRV yourself without a gauge; guessing at the setting can leave pressure too high or starve upper floors of flow 

Frequently Asked Questions 

Is 100 PSI Water Pressure Too High? 

Yes. Most homes are designed to run safely at 40 to 80 psi, and 100 psi is high enough to stress pipes, fittings, and appliances over time even if nothing fails right away. 

Is 80 PSI Too Much Water Pressure? 

No. 80 psi is generally treated as the top of the normal range. Many plumbing codes use 80 psi as the threshold above which a pressure regulator becomes necessary, so 80 psi itself is not a problem, but pressure that regularly climbs past it is worth checking. 

What Is a PRV in Plumbing? 

PRV stands for pressure reducing valve, a mechanical valve installed on the main water line that lowers incoming municipal pressure down to a safe range for the home. It is the standard fix for consistently high water pressure. 

What Should Normal Household Water Pressure Be? 

Most plumbing professionals consider 40 to 80 psi normal for a residential system, with pressure in the 50 to 70 psi range feeling comfortable at most fixtures without running weak. 

How Do I Test My Home’s Water Pressure Myself? 

Attach an inexpensive hose bib pressure gauge (available at most hardware stores) to an outdoor spigot or a washing machine hookup, turn the water on all the way, and read the psi directly off the gauge. If it reads 100 psi or higher, or you are not sure how to interpret the reading, have a licensed plumber confirm it with a calibrated gauge. 

Schedule a Water Pressure Check 

If your home’s water pressure is running at 100 psi or higher, the fix is straightforward for a licensed plumber: a properly sized and calibrated pressure regulator valve, installed and set correctly, protects every pipe, fixture, and appliance in the house. Golden Rule’s plumbers can test your incoming pressure, install or replace a pressure regulator valve, and check it against your fixtures and water heater to make sure the whole system is protected. 

Call Golden Rule at (515) 393-4526 or request service online at goldenrulephc.com to schedule a water pressure check and pressure regulator valve installation. 

Further reading: 

• U.S. EPA WaterSense: water efficiency and pressure-related fixture guidance (epa.gov/watersense) 

• National Fire Protection Association (NFPA): why municipal systems maintain higher water pressure for fire hydrants (nfpa.org)