Is My Water Pressure Too High? Signs & Fixes
Short answer: if your static water pressure reads above 80 psi, it's too high. The plumbing code adopted in Arizona caps residential pressure at 80 psi, and most homes do best between 55 and 65 psi. Many Scottsdale, Phoenix and Paradise Valley homes sit on city mains that deliver 90–120 psi, so a working pressure reducing valve (PRV) is what keeps that pressure out of your pipes. A $15 gauge on a hose bibb tells you in two minutes.
High water pressure feels like a good thing in the shower. Behind the walls it's a slow problem. It strains every joint, supply line, valve and appliance in your home, all day, every day. Here's how to tell whether your pressure is too high, how to test it yourself, and what fixing it costs in 2026.
Signs your water pressure is too high
- Banging or hammering pipes when a faucet, washer or sprinkler valve shuts off (water hammer).
- A toilet that runs or refills on its own. High pressure pushes water past the fill valve.
- Dripping faucets and shower heads soon after they were replaced.
- Water heater relief valve dripping or a wet pan under the tank.
- Faucets that spray or spit when you open them, even at low settings.
- Burst washing machine hoses, toilet supply lines or icemaker lines.
- Appliances failing early. Dishwashers, washers, water heaters, softeners and RO systems all wear faster.
- Pressure that swings. Strong one moment and weak the next usually means a PRV is failing.
One sign alone can have another cause. Two or three together almost always point to pressure.
How to test your water pressure (2 minutes)
- Buy a hose-thread pressure gauge ($10–$20 at any hardware store). One with a red "max reading" needle is best.
- Turn off every faucet, sprinkler and appliance using water inside and outside.
- Screw the gauge onto an outdoor hose bibb closest to where water enters the house, usually near the PRV.
- Open the hose bibb fully and read the gauge. That's your static pressure.
- Leave it on for an hour or overnight if it has a max needle. A reading that climbs well past the first number points to thermal expansion or a creeping PRV.
How to read the number:
| Reading | What it means |
|---|---|
| Under 40 psi | Low. Look for a failing PRV, clogged fixtures, or a supply issue. |
| 40–54 psi | Acceptable, on the soft side. |
| 55–65 psi | Ideal for most homes. |
| 66–80 psi | Allowed, but hard on fixtures over time. |
| Over 80 psi | Too high. Above code and damaging to plumbing. |
Why pressure runs high in the Scottsdale area
Cities keep main pressure high so water reaches hillside homes, upper floors and fire hydrants. Homes lower in a pressure zone, or close to a pump station, can see 100 psi or more at the meter. That's why most Valley homes have a PRV, a bell-shaped brass valve on the main line near the front hose bibb or in the garage.
PRVs don't last forever. Hard water (12–18 grains here) scales up the internal spring and seat, and most valves wear out in about 7–12 years. When a PRV fails, it usually fails open. Full street pressure then reaches your home, and many people don't notice until a supply line bursts.
The link to your water heater and expansion tank
A PRV makes your plumbing a closed system. When your water heater warms a fresh tank of water, that water expands and has nowhere to go. Pressure can spike past 120 psi for a few minutes after each heating cycle, even with a good PRV. A properly charged thermal expansion tank absorbs that spike. If your gauge's max needle jumps overnight, the expansion tank is the first thing to check. Our guide on whether you need an expansion tank explains the details.
What high pressure actually damages
- Supply lines and hoses. Braided lines are rated for normal pressure; constant high pressure is one of the most common causes of burst lines and flooded kitchens and laundry rooms.
- Pipes and joints. Pinhole leaks and fitting failures happen faster, including slab leaks under the floor.
- Water heaters. Relief valve discharges and tank stress shorten tank life.
- Fixtures. Faucet cartridges, toilet fill valves and shower valves wear out early.
- Your water bill. Every open faucet and irrigation zone flows more water than it needs to.
Many manufacturers' warranties also require pressure at or below 80 psi. A failed appliance on a high-pressure system may not be covered.
How to fix high water pressure
1. Adjust the existing PRV. Most valves have an adjusting bolt on top. If the valve is healthy, a plumber can set it to 55–65 psi in a short visit. Adjustment starts at $165.
2. Replace the PRV. If the valve won't hold a setting, creeps up overnight, hums or leaks, it needs to be replaced. A typical PRV replacement runs $450–$850 in 2026. Hard-to-reach valves, corroded galvanized connections or a missing shutoff can push a job toward $1,300.
3. Add or recharge an expansion tank. If static pressure is fine but spikes after the water heater runs, the fix is an expansion tank. Installation typically runs $225–$425.
| Fix | Typical 2026 cost | When it's the right call |
|---|---|---|
| PRV adjustment | From $165 | Valve is healthy but set too high |
| PRV replacement | $450–$850 (up to ~$1,300 for difficult installs) | Valve is old, won't hold pressure, or leaks |
| Expansion tank install | $225–$425 | Pressure spikes after water heater cycles |
Should you adjust the PRV yourself?
You can turn the adjusting bolt with a wrench while watching a gauge, and some homeowners do. Be careful with an old valve. The locknut and bolt are often seized with scale, and forcing them can crack the bell housing. If the valve is more than about 10 years old, won't respond to adjustment, or you have no working main shutoff, leave it to a licensed plumber.
When to call a plumber
Call if your pressure reads above 80 psi, if it climbs overnight, if your water heater relief valve drips, or if you hear banging pipes. We test pressure on every service call, and we'll tell you whether an adjustment, a new valve or an expansion tank is the right fix. See our pressure reducing valve replacement service for details. Local versions: PRV replacement in Scottsdale, Phoenix, Tempe and Mesa.
Frequently asked questions
What is normal water pressure for a house? Between 40 and 80 psi is acceptable, and 55–65 psi is ideal for most homes. The plumbing code adopted in Arizona limits residential pressure to 80 psi.
Is 100 psi water pressure too high? Yes. 100 psi is well above the 80 psi code limit and will wear out supply lines, fixtures and appliances early. It usually means your PRV has failed or is missing.
How do I know if my pressure reducing valve is bad? Common signs are pressure above 80 psi, pressure that climbs overnight, banging pipes, a running toilet, a dripping water heater relief valve, or a valve that hums or leaks. A gauge on a hose bibb confirms it.
How much does it cost to fix high water pressure in Scottsdale? A PRV adjustment starts at $165. A PRV replacement typically costs $450–$850 in 2026, with difficult installs up to about $1,300. An expansion tank install runs $225–$425.
How long does a pressure reducing valve last? Most PRVs last about 7–12 years. Hard water in the Scottsdale area can shorten that by scaling up the valve's spring and seat.
Can high water pressure cause a slab leak? It's one of the contributing factors. Constant high pressure stresses pipes and joints under the slab, especially older copper, and can speed up pinhole leaks.