How often should you check your home's water pressure?

Short answer

Check the home's water pressure once a year. Screw a water pressure gauge onto an outdoor hose faucet, open the faucet, and read the dial. The gauge costs $10 to $15 and the reading takes 5 to 10 minutes. A reading above 80 psi means the pressure regulator on your main line has failed or isn't there, and high pressure is quietly wearing out every valve, hose and appliance in the house.

Why it matters

Water arrives from the street at whatever pressure the utility runs, which is often far higher than a house should see. A pressure regulator on the main line knocks it down to a level the plumbing was designed for. Regulators wear out, and when one fails the pressure creeps up and nobody notices, because the taps just run a bit harder.

High pressure hits the weakest parts first. Washing machine hoses bulge. Toilet fill valves and faucet cartridges drip. The water heater's relief valve starts weeping because the tank pressure spikes every time the water heats. Dishwasher and ice maker lines fail. Each of those looks like a separate problem, and a plumber fixing them one at a time may not think to check the pressure behind all of them. A yearly reading catches the real cause, and replacing a regulator is far cheaper than replacing everything it was protecting.

When to do it more often

Once a year is the schedule for a home where the reading comes back normal. The reasons to test sooner are the symptoms of high pressure showing up between readings:

Pipes that bang when a tap or the washing machine shuts off.
A relief valve on the water heater that drips after being replaced.
Appliance hoses that keep failing, or faucets that drip soon after a repair.
A new water heater or washing machine. Test before connecting it, so high pressure doesn't shorten its life from day one.

What you need

A water pressure gauge that screws onto a hose faucet, sold with the hose fittings at any hardware store

Steps at a glance

Make sure no water is running in the house, including the washing machine, dishwasher and sprinklers.
Screw the gauge onto an outdoor hose faucet, or the washing machine's cold valve.
Open the faucet fully and read the dial once the needle settles.
Note the reading and the date.
Test again at a busy time of day, since street pressure changes, and keep the higher reading.
If the reading is above 80 psi, find the regulator on the main line and have it adjusted or replaced.

You're done when you have a reading, and it's below 80 psi.

Signs it's overdue

Banging pipes when a tap shuts off.
Dripping faucets that keep coming back after repair.
A leaking water heater relief valve.
Appliance hoses that keep failing.
A gauge reading above 80 psi.

DIY or pro

Testing is an easy job. The gauge screws on like a hose, and the dial reads like a tire gauge. Keep it in the drawer with the other tools and it lasts for years.

Fixing high pressure is a plumber's job. A regulator sits on the main line near where water enters the house, and replacing one costs $250 to $600. Some regulators can be adjusted with a screw, and a plumber will try that first on a unit that isn't too old. If your house has no regulator at all and the reading is high, adding one protects every fixture you own.

Safety

Pressure: the gauge is only reading what's already in the pipes, so the test itself is safe. The danger is the pressure you find. A reading well above 80 psi means the water heater's relief valve and every hose in the house are being pushed past what they're rated for. Don't ignore it or cap a dripping relief valve to make the symptom go away, and have a plumber lower the pressure soon.

FAQ

What should my home's water pressure be?

Below 80 psi. A reading above that means the regulator needs adjusting or replacing.

How do I test water pressure at home?

Screw a hose-thread pressure gauge onto an outdoor faucet or the washing machine valve, open it fully, and read the dial.

What causes high water pressure in a house?

A failed or missing pressure regulator on the main line. The utility supplies more pressure than a home needs, and the regulator is what brings it down.

Can high water pressure damage a water heater?

Yes. The pressure spikes as the water heats, and the relief valve opens or the tank is stressed. A dripping relief valve is often the first sign.