How to Fix Super-High Water Pressure

High water pressure

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Project Overview
  • Total Time: 1 - 2 hrs
  • Skill Level: Intermediate
  • Estimated Cost: $50

High water pressure: It feels great in the shower, but it may be costing more than you think. High-pressure water can cause serious problems like pinhole leaks in your plumbing and it can severely shorten the life of your water heater, dishwasher, boiler system, and washing machine and increase your water bills.

Is My Water Pressure Too High?

The signs are well known: Banging pipes, running toilets, dripping faucets, and running out of hot water very quickly all indicate that the pressure is too high in your system. Test your system with a water pressure gauge, available at any home store for around $10. Simply attach the gauge to any male threaded faucet such as your laundry tub, hose bib, or water heater drain connection and turn on the water. The ideal pressure for the health of your plumbing system and appliances is between 40 and 60 PSI, and building codes in most areas specify that water pressure be under 80. If yours measures over 80 PSI on the gauge, it is definitely time to lower the pressure.

Water Pressure Regulators

To get your pressure to the recommended levels, you will need a water pressure regulator. This is a common plumbing valve installed right after the pipe from the water meter enters the house. If you already have one installed and you still have high pressure, chances are it needs to be adjusted (see below), repaired or replaced. If you do not already have one installed, it may be time to call the pros. It is an inexpensive and easy job for a trained plumber but may require adjusting the height of the water main and other advanced tasks.

In most cases, if a water pressure regulator is required, the town or local municipality is responsible so check with them first. Although a general description for replacing and adjusting the water pressure for a PRV is noted below, this should likely be done by a trained professional.

There are other variables that need to be considered when it comes to working with a water pressure regulator, including ascertaining whether or not the main water valve holds, and examining the condition of the incoming water-service support for the water distribution piping in the location where you plan to work.

If you're replacing a water pressure regulator, the old one and new one are often not an exact match. Soldering or brazing may be required when connecting dissimilar materials. Take this possibility into consideration when deciding if you want to call a professional.

What You'll Need

Equipment / Tools

  • Safety goggles
  • Bucket
  • 2 Wrenches
  • Screwdriver

Materials

  • Plastic sheeting
  • New water pressure regulator valve

Instructions

1:31

Watch Now: How to Test Your Home's Water Pressure

How to Adjust Your Water Pressure Regulator

  1. Turn Off the Water

    Locate the water main and slowly turn the valve to the off position.

  2. Adjust the Pressure

    The regulator will have a screw or bolt and a locking nut system. Loosen the locking nut with a wrench and using quarter-turn increments, use a screwdriver to turn the screw counter-clockwise (to the left) to decrease water pressure, and clockwise (to the right) to increase water pressure.

  3. Re-test the System

    Go back to the water pressure gauge and re-test the system (remember: keep pressure between 40 and 60 PSI).

  4. Secure the Lock Nut

    Once the pressure is where you want it, secure the lock nut on the regulator using a wrench to ensure the adjustment screw does not move.

  5. Turn the Water Back On

    Go to the water main and slowly turn the main water valve back on. You may want to run a faucet for a few seconds to clear any air out of the system.

How to Replace a Water Pressure Regulator

  1. Locate Your Water Pressure Regulator

    The regulator is typically installed right after the water enters the home, near the water main. Once you locate it, write down the specifications. Purchase your new one with as close to the same specifications so you can use the connections that are already in place.

  2. Turn Off the Water at the Main

    Locate the water main and slowly turn the shut-off valve to the off position.

  3. Drain the Water From the Plumbing System

    Drain the water from the system by opening the highest and lowest faucets in the house. Doing both will eliminate a vacuum and ensure as much of the water drains out as possible.

  4. Set up Your Plastic Sheeting and Bucket

    Even though you have drained the water, some water will be trapped inside the old valve. Set up plastic sheeting underneath and behind your work area. Alternatively (or in addition) place a bucket beneath the old valve on the ground.

  5. Prep the New Valve

    Since you are using the existing connections, you need to remove the nuts on either side of the new valve, as you will not be using them. Pay attention and save the O-rings that come with the new valve—you will need these, so take care not to lose them.

  6. Remove the Old Regulator

    Loosen the nuts on each side of the old regulator with a wrench. Hold the regulator in place with another wrench while you finish unscrewing the nuts by hand, ensuring it doesn't twist and bend the plumbing or compromise the threads. Remove the old regulator carefully—this is the step where the water will come out, and you'll be glad you set up that bucket.

  7. Install the New Regulator

    Seat the O-rings and install the new regulator. The valve is directional and must be installed right side up. This means the water should flow in through one side and out of the other. There will be an arrow on the side of the valve indicating the proper direction. Hand tighten each union, taking time to make sure the O-rings are in the proper position.

  8. Finish Tightening the Nuts

    Use a wrench to finish tightening the nuts. Do not over-tighten, but make sure they are snug.

  9. Test for Leaks

    Dry off the pipes and the new regulator. Slowly open the main water line, and allow the faucets to run until all of the air is bled from the lines. Turn the faucets off after they have stopped sputtering. Return to the work area and inspect for leaks. Some leaks can be slow, so take your time and be thorough in this process. If you see a slow leak, try reseating the O-rings.

  10. Adjust to Desired Pressure

    Using the steps detailed above, adjust your new regulator to the desired water pressure. Your plumbing system is now ready to use.