If you turn on your faucet and feel like it’s trying to powerwash your dishes—or your shower now feels like a firehose—it’s not just in your head. Sudden high water pressure is a real thing. And while it might feel great at first, it’s actually not something you want to ignore.
Here’s what causes it, how to tell if it’s happening, and what to do before it messes with your plumbing.
🔧 First, What’s “Normal” Water Pressure?
Most homes are designed to run on water pressure between 40 and 60 psi (pounds per square inch). Anything above 80 psi is usually considered too high—and could cause issues like leaks, burst hoses, or noisy pipes.
If you suddenly jump from 55 to 90+ psi, things can get rough fast—especially for older plumbing, cheap supply lines, or water-using appliances like washing machines and dishwashers.
📉 Symptoms of High Water Pressure
Here’s how to tell if your water pressure is out of whack:
- 💥 Faucets or showerheads spray unusually hard
- 💧 Pipes knock or bang when water shuts off (a.k.a. water hammer)
- 🚿 Hot water runs out quickly or sputters
- 🧺 Washing machine or dishwasher sounds louder or fills too fast
- 🏠 Leaks or drips from pipe joints, water heaters, or toilet fill valves
And if your toilet sounds like it’s hissing long after it’s done filling? That’s another clue something’s off.
🕵️ Why Would Pressure Suddenly Spike?
There are a few reasons why pressure might rise out of nowhere:
1. Failed Pressure Regulator (PRV)
If your home has a pressure-reducing valve (usually located near the main water shutoff), it could be malfunctioning. These valves are supposed to bring city water pressure down to safe levels. When they fail, they often stick wide open, allowing full street pressure into your home—sometimes over 100 psi.
What to check: If your PRV is more than 10 years old or the pressure issue affects every faucet in the house, it’s a likely culprit.
2. City Water Supply Fluctuations
Sometimes the spike isn’t your fault at all. Municipal water pressure can change depending on time of day, nearby construction, or pump maintenance. If your house is at the bottom of a hill or near a major main, those fluctuations can be pretty extreme.
What to check: Ask neighbors if they’re seeing the same thing. If not, it’s probably something in your own system.
3. Thermal Expansion
This one’s sneaky. When water is heated (like in your water heater), it expands. If there’s no expansion tank or your thermal check valve is failing, that extra volume has nowhere to go—and pressure spikes.
Signs: Pressure jumps mostly after someone uses hot water, or the relief valve on your water heater starts dripping.
4. Well Pump Issues (If You’re on a Well)
For private well systems, a faulty pressure switch or broken pressure tank bladder can cause sudden surges. If the pump doesn’t cycle correctly, it might overshoot the target psi before shutting off.
Clue: Pressure gauge shows pressure rising well beyond normal cut-off range (like 40–60 psi), and pump runs longer than usual.
💥 What Can High Pressure Actually Damage?
You might be thinking: “Eh, more pressure = stronger showers, right?” Not so fast. Here’s what it can ruin:
- 🚽 Toilet fill valves (they start leaking or hissing constantly)
- 🔧 Flexible supply lines (they can burst—especially old braided ones)
- 💧 Water heaters (relief valves start dripping; tanks may fail prematurely)
- 🧼 Washing machines & dishwashers (internal seals can blow out)
- 📢 Pipes (water hammer and loose joints are more likely)
Bottom line: high water pressure might feel powerful, but it quietly wears out your plumbing faster than you’d think.
📏 How to Measure Your Water Pressure
You can buy a simple water pressure gauge at any hardware store (usually $10–$15). Screw it onto a hose bib or laundry faucet and turn on the water. Look for pressure between 40 and 60 psi. Anything over 75? That’s high. Over 80? Time to act.
🛠️ What You Can Do About It
✅ If You Have a PRV (Pressure Regulator Valve)
- Check the pressure at a hose bib or laundry sink
- If pressure is over 75 psi, try adjusting the PRV (usually a bolt on top)
- If adjustment doesn’t work, the valve may need replacing
✅ No PRV? Consider Installing One
If your home doesn’t have a regulator and your city pressure is consistently high, it’s worth installing one. They typically go right after the main shutoff valve and last 10–15 years.
✅ Add a Thermal Expansion Tank
If pressure spikes only happen when using hot water—or you notice water dripping from your water heater’s pressure relief valve—you probably need an expansion tank.
✅ Call the City (Sometimes It’s Their Fault)
If your whole neighborhood has pressure spikes, the city may need to adjust their delivery pressure or check for a broken main.
🚩 When to Call a Plumber
If you’ve tested your pressure and it’s well above 80 psi—or you’re hearing pipe noise, seeing leaks, or noticing water heater issues—it’s smart to get a plumber involved. Especially if your PRV is buried or tough to access.
A licensed pro can:
- Test system pressure at multiple points
- Replace your PRV or install one if needed
- Install expansion tanks or pressure relief valves
- Inspect pipes for strain or weak points
Final Thoughts
Sudden high water pressure isn’t just annoying—it can quietly wreck your plumbing system over time. Whether it’s a failed regulator, temperature-related expansion, or a hiccup from the city supply, the key is to catch it early. Grab a pressure gauge, check your lines, and if things look off, don’t wait too long to fix it.
Your pipes—and your wallet—will thank you.