Water pressure refers to the force water exerts on the inside of pipes and is measured in pounds per square inch (PSI). Water pressure within the Centennial Water service area can range from 45 to 150 PSI.  If your water pressure is below 70 PSI and you don’t have a pressure reducing valve (PRV), you may be located inside of an area of the water system where a PRV is not needed. 

Right: Example of a pressure reducing valve (PRV).

High Pressure

High water pressure can result in leaks, pipe damage and wasted water. High water pressure can be controlled by a PRV installed prior to the water meter. PRVs are usually located in a basement, crawl space or garage, underneath the water meter. 

The recommended maximum water pressure inside your home is 70 PSI, especially if you have a water softener or a sprinkler system.

Low Pressure

Low water pressure is generally considered anything less than 40 PSI. Low water pressure can be caused by a variety of things including plugged faucet aerators, a malfunctioning PRV, plugged water softener, whole house water filtration system, etc.  If you are experiencing unusually low water pressure and cannot diagnose the cause, please call Centennial Water at 303-791-2185 and we will perform a pressure check.

Pressure Issues

We can offer basic information on pressure issues. Every situation is different and it is by no means professional plumbing advice.

To the right is a photograph of the typical water main/ meter stack installation. Yours may look different, depending on the type of installation. Your water meter may also be located in a pit in the front yard. These stacks are typically located in the basement, garage or crawl space.

Check the shut-off valves

Check your shut-off valves to ensure they are in the fully open position. If you have a lever handle, it should be parallel with your pipes. If the handle is perpendicular to the pipe or at an angle, that indicates your valve is partially or completely closed. If you have a round handle, it should be opened all the way counter clockwise. If you turn it to the right and it won’t move, then it is in the closed position.

Check your pressure at an outside hose bib

Next check your house’s water pressure. Make sure there is no water being used in the house or with the irrigation system. Thread, like you would a garden hose, a pressure gauge (this can be purchased at home improvement stores for less than $15) onto your outside hose bib, and turn the faucet on all the way. This will give you a baseline of your house’s pressure. Standard household pressure should be 40-70 psi. Pressures higher than 70 can possibly damage household appliances. If your pressure is higher than 70 your pressure should be reduced, using a pressure regulating valve.

Adjusting a pressure regulating valve

Once you have determined your household pressure, you may be able to adjust it up or down using your PRV. You will need a flathead screwdriver and a wrench. The PRV is normally located in the basement, where your water shut-offs are located. The PRV is a bell shaped fixture with a locknut and bolt on the end. Loosen the locknut, by turning it counterclockwise with a wrench, before trying to adjust the pressure, this will allow you to maneuver the bolt. Turn the screw clockwise to tighten –increasing the pressure, or counter clockwise to loosen and lower the pressure. After each full turn of the screw, take a new reading at your outside faucet, ensuring you are not raising the pressure too high or too low. Remember to count the turns, in case you want to reset the PRV to its original position. The pressure should not be adjusted above 70 psi. Once you have reached the desired water pressure, make sure you re-tighten the locknut on the PRV.

Is your pressure regulating valve failing?

The most common signs that a PRV is failing are:

• Sudden loss of water pressure and water flow
• Suddenly high water pressure
• Water pressure surges- often when a PRV is starting to fail, the water will come out strongly when the faucet is first turned on and then taper off. This means the PRV is unable to hold the water pressure and maintain the pressure in your system.

There are many YouTube videos that explain how residential plumbing systems and PRVs work. It is wise to educate yourself before you call a plumber!

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