A strong shower feels great, but water pressure that’s too high can quietly strain your plumbing. It may cause pipes to bang, toilets to keep running, and appliances to wear out sooner than they should. The good news is that you can check the pressure with an inexpensive gauge and, in many homes, fix the problem with a pressure-reducing valve. The key is to measure first and make adjustments safely.
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What Counts as High Water Pressure?
Water pressure is measured in pounds per square inch, or PSI. Many homes work well at roughly 40 to 60 PSI, but the right range can depend on your plumbing, appliances, and local requirements. As a general rule, pressure above 80 PSI is considered excessive in many plumbing codes and should be checked. Always confirm the standard that applies where you live.
High pressure can be easy to miss because faucets still work and showers may seem perfectly normal. The trouble is that pressure affects your entire plumbing system, even when no water is running. Extra force puts ongoing stress on pipe joints, fixture seals, hoses, valves, and appliances such as washing machines and water heaters.
Signs Your Home May Have Excessive Water Pressure
A single symptom doesn’t prove that pressure is the cause. A worn faucet cartridge, a loose pipe, or a faulty toilet part can create similar problems. But several signs together are a good reason to measure your pressure.
- Water bangs or pipes knock: Sudden changes in water flow can make pipes move or create water hammer. High pressure can make the impact stronger.
- Faucets or showerheads leak: Pressure can put extra strain on seals and cartridges, though age and mineral buildup are common causes too.
- Toilets run or refill often: Excess pressure may contribute to wear on fill valves and other parts inside the tank.
- Appliance hoses fail: Washing machine and dishwasher hoses are under pressure even when the appliance isn’t running.
- Water flows unusually forcefully: A strong stream can be a clue, but it isn’t a dependable measurement on its own.
- Your pressure changes at different times: Pressure that rises overnight or when nobody is using water may point to a regulator or thermal expansion issue.
Measure the Pressure Before You Adjust Anything
Use a water pressure gauge
A threaded pressure gauge that connects to a hose bib or laundry faucet is usually inexpensive and simple to use. Choose a connection that’s supplied by the home’s plumbing, not one downstream of a special filter or small appliance valve if you’re trying to measure the main household pressure.
- Turn off taps, showers, dishwashers, washing machines, and other water-using equipment.
- Screw the gauge onto an outdoor hose bib or suitable threaded faucet. Make sure the connection is snug so water can’t leak around it.
- Open the faucet fully and read the gauge. With no water running elsewhere, this is a static pressure reading.
- Check more than once. If the gauge has a second needle that records peak pressure, leave it connected for a while to see whether pressure rises when you’re not using water.
If the reading is consistently over 80 PSI, contact your water provider or a licensed plumber to discuss the next step. If it is around 50 to 60 PSI, that may be suitable for many homes, but follow local rules and the needs of your plumbing system. Don’t try to judge pressure by partly closing the main shutoff valve; that valve controls flow, not pressure, and using it as a regulator can cause problems.
How to Reduce High Water Pressure
1. Check whether you already have a pressure-reducing valve
A pressure-reducing valve, often called a PRV or pressure regulator, lowers incoming water pressure before it reaches the household plumbing. It’s commonly installed near the main water shutoff, where the supply line enters the house. You may see a bell-shaped fitting with an adjustment screw or bolt on top, but layouts vary.
If you already have a PRV, it may simply need adjustment. It may also be worn, stuck, or failing. A regulator can stop controlling pressure properly as it ages, so turning the screw isn’t always the fix. Look for a model label or manufacturer instructions before making any adjustment.
2. Adjust the PRV carefully, if the manufacturer allows it
Some PRVs can be adjusted with a screw or bolt. On many common models, turning the adjustment clockwise raises the outlet pressure and turning it counterclockwise lowers it. That direction isn’t universal, so check the product instructions first.
Make small changes, then measure again with the gauge. For example, if your reading is 90 PSI, don’t make a large guess-and-check turn. Reduce it a little, recheck, and continue gradually until you reach a suitable setting. Avoid setting the pressure lower than your household needs; pressure that’s too low can make showers and appliances work poorly, especially if your home has multiple floors.
If the valve is corroded, leaking, hard to turn, or has no clear adjustment instructions, stop and call a plumber. Forcing the screw can damage the regulator or create a leak.
3. Install or replace a PRV when needed
If there’s no regulator and incoming pressure is too high, a plumber can install a PRV on the main supply line. If an existing valve no longer controls pressure, replacement may be the better fix. Proper installation matters: the valve needs to match the pipe size and water conditions, be installed in the correct direction, and remain accessible for future checks.
Rules for plumbing work differ by location. A permit or inspection may be required, and work on the main supply line can cause leaks or interrupt service if done incorrectly. If you’re unsure, hiring a licensed plumber is the safer choice.
4. Check for thermal expansion in a closed plumbing system
Sometimes pressure looks normal when you test it, then climbs after the water heater runs. Heating water makes it expand. In a plumbing system that prevents water from flowing backward into the public supply, that extra volume can raise pressure inside the house.
A thermal expansion tank can absorb that added volume, but it must be sized and charged correctly for the system. A tank that has lost its air charge or has a damaged bladder may not do its job. If pressure rises mainly after hot water is used, ask a plumber to check the expansion tank, the PRV, and any backflow-prevention equipment.
5. If you’re on a well, check the pump system
Homes supplied by a private well usually use a pressure tank and pressure switch rather than a municipal PRV alone. The switch starts and stops the pump at set pressures. If the system is set incorrectly or a component is failing, the pressure may become unstable or exceed the intended range.
Don’t adjust the pressure switch based on a guess. The switch, pump, and pressure tank need to work together, and incorrect settings can damage the pump or leave the house with unreliable water. Have a well professional inspect the system.
Quick Guide to the Likely Cause
| What you notice | Possible cause | Useful next step |
|---|---|---|
| Pressure stays high throughout the day | High supply pressure or a faulty or missing PRV | Measure at a hose bib and ask your water provider or plumber about regulation |
| Pressure rises after the water heater runs | Thermal expansion in a closed system | Have the expansion tank and backflow setup checked |
| Pressure fluctuates in a well-supplied home | Pressure switch, tank, or pump issue | Arrange an inspection by a well professional |
| One faucet has a weak or uneven stream | Clogged aerator, fixture problem, or local restriction | Check that fixture before changing the home’s pressure setting |
What Not to Do
- Don’t use the main shutoff valve as a pressure control. Partly closing it can restrict flow and may cause noise or other issues; it doesn’t replace a PRV.
- Don’t ignore a leaking pressure regulator. A small leak can worsen, and water near electrical equipment or a water heater needs prompt attention.
- Never cap or block a water heater’s temperature-and-pressure relief valve. It’s a safety device. If it discharges, have the cause checked rather than disabling it.
- Don’t keep turning an adjustment screw if readings don’t respond. The valve may be broken, incorrectly installed, or the source of the pressure problem may be elsewhere.
When to Call a Plumber
Call a licensed plumber if your gauge repeatedly reads above the local limit, you can’t identify the regulator, or pressure keeps climbing after adjustments. It’s also wise to get professional help if you see water around the PRV, hear repeated pipe banging, have a pressure rise tied to water-heater use, or need work done on the main supply line.
If you rent, contact your landlord or property manager rather than adjusting shared plumbing. In some cases, your water provider can confirm the pressure at the service connection, which helps separate a supply-side issue from a problem inside the house.
Read more related posts:
- 10 causes of low water pressure in bathroom showers what to do
- Discover why does a bathroom air vent drip water safely and how to fix
- Discover how to tell if bathroom humidity is too high safely and
Frequently Asked Questions
Is 80 PSI too high for a house?
Pressure above 80 PSI is considered excessive under many plumbing standards, but local rules can differ. Measure the pressure and check your local requirements or ask a licensed plumber.
Can I lower water pressure by partly closing a faucet or shutoff valve?
No. Partly closing a valve may reduce flow at that point, but it doesn’t properly regulate the pressure throughout the home. A correctly selected and installed PRV is designed for that job.
Where is the pressure-reducing valve usually located?
It’s often near the main shutoff where the water supply enters the house. The exact location depends on the plumbing layout, and some homes don’t have one.
Why does pressure rise after I use hot water?
Water expands as it heats. In a closed plumbing system, that expansion can raise pressure unless a properly working thermal expansion tank or other suitable arrangement absorbs it.
Conclusion
Start by measuring your home’s pressure with a gauge rather than relying on how forceful the shower feels. If readings are consistently high, check for a PRV and follow its instructions carefully; a faulty regulator, thermal expansion, or a well-system issue may need professional attention. A measured, correctly handled fix helps protect pipes, fixtures, and appliances without leaving your home with pressure that’s too low.
