It’s a good idea to test water pressure in your home a couple of times per year as part of a plumbing maintenance checklist. Testing water pressure is quick and easy, and all you need is a simple and inexpensive pressure gauge. Some homes even have dedicated gauges hooked up somewhere in the water line so homeowners can check the water pressure quickly and easily with just a glance. But if you don't have a permanent gauge, it is very easy to do a periodic test with a standard water pressure gauge.
Why Test Your Home's Water Pressure?
Having too much water pressure can be hard on all plumbing lines and fixtures and can even cause blowouts in flex lines or washing machine hoses, which in turn can flood the house. It’s a good idea to test water pressure even if your home has a pressure regulator, or pressure-reducing valve (PRV), on the main water supply because it isn’t necessarily obvious when a regulator fails. Testing water pressure occasionally can catch a problem with the pressure regulator before the high pressure can damage any plumbing.
If you discover that you have low water pressure, call your water supplier or utility, and ask about having someone come out to look at the issue. In some cases, the water supplier owns the house PRV (pressure reducing valve) and can make adjustments easily.
Equipment / Tools
- Water pressure gauge
- Tongue-and-groove pliers (as needed)
Choose the Testing Location
If your water comes from a city or municipal water utility, select an outdoor hose bib faucet (spigot) closest to where the home's main water supply line (from underground) enters the house. If you get your water from a well, use a faucet or fixture that is close to the well's pressure tank. You will get the most accurate reading if the hose bib or faucet is fed by a supply pipe that is the largest size inside the house, as it has not been reduced like the supplies to bathroom plumbing fixtures, for example. This size is likely to be 3/4-inch, which is preferable, but it may be 1/2 inch.
Check for Running Water
To get an accurate reading when you test water pressure, make sure water isn’t being used anywhere inside or outside the house. Turn off washing machines, sprinklers, refrigerators with ice makers, and dishwashers. When you test the pressure with a gauge, you are measuring the static water pressure; if water is moving anywhere in your plumbing system, it may result in a falsely low reading.
Install the Pressure Gauge
Remove the hose from the faucet, if there is one connected; do not perform the test with a hose. Thread the pressure gauge onto the faucet. There will be a rubber gasket inside the pressure gauge, and you should be able to simply hand-tighten the pressure gauge and get a good seal. But if this connection leaks a little during the test, tighten it a bit more with tongue-and-groove pliers or an adjustable wrench. A good seal is necessary for an accurate reading.
Use a gauge that reads in psi (pounds per square inch) and has female hose threads so you can screw it onto a hose bib or washing machine bib faucet.
Check the Pressure
Turn the faucet all the way, then read the pressure on the gauge's dial. Typical home water pressure ranges from 40 to 50 psi and generally should not exceed 60 psi. Most standard pressure regulators have a maximum adjustment up to 75 psi, so if the reading on the pressure gauge is over 75 psi, then you know that the pressure regulator is not working correctly and will have to be repaired or replaced. If you don't currently have a pressure regulator installed and the water pressure reading is over 60 psi, consult a plumber about having a regulator installed.
Testing at the Washing Machine
An alternate place to test your water pressure is at your washing machine's cold water supply faucet. Shut off the cold water at the faucet behind the washing machine, then disconnect the hose from the faucet (be careful as it will be full of water). Screw the pressure gauge onto the faucet, then open the faucet all the way to test the pressure.