You can check the water pressure in mains, or main household water lines, by using a standard water pressure gauge available from any hardware store. Install the water pressure gauge at the point where the municipal water supply comes into the home for a measurement of main water line pressure. Maintaining accurate water pressure prevents unnecessarily high water bills and conserves water. It also protects household pipes, appliances, sprinkler systems and swimming pool lines by preventing unnecessary wear caused by a water pressure that's too high.
Locate the primary water spigot, which should be positioned at the front of the house, as this is where the municipal water supply flows into the home.
Attach a water pressure gauge to the spigot, just as one would connect a standard garden hose.
Turn off all appliances and fixtures that are connected to the household water supply, including swimming pool lines, refrigerator and freezer lines, dish and clothes washers and water cooled air conditioners.
Turn on the outside spigot, to which the water pressure gauge is attached, and note where the gauge's needle stops. Repeat this step twice more at varying times during the day and evening, and note the gauge's needle readings.
Average the three water gauge readings by adding the numbers and dividing by three. Correct household water pressure in the mains should be between 24.9 and 29.5 Kilogram per square inch (PSI).
Hire a plumber to install a water pressure regulator to the household water lines if the average water pressure reading is higher than 65 PSI.