(206) 949-5683, Top Rated Plumber, Seattle
Results 1 to 13 of 13

Thread: Pressure creep with bad PRV

  1. #1
    DIY Junior Member santhon2's Avatar
    Join Date
    Jan 2014
    Location
    Georgia
    Posts
    5

    Default Pressure creep with bad PRV

    I have major water pressure creep all the time. New water heater installed with expansion tank and the pressure is being relieved by the pressure release valve. I have tested the lines with a pressure gauge and the flow is regulated at 40-50 psi when running. The gauge registers a high of 150 psi over night which triggers the release valve. I have tested the line with the water heater turned off so I know it's not thermal expansion. My question, is the pressure regulator valve on the incoming line supposed to shut off the inlet when the line pressure reaches the set psi at say 50 or do they usually allow the pressure to continue? Do I need a different valve to keep out the higher pressure? I am the last house at the end of the street and I believe the water main ends here and does not continue. Not sure if the pressure regulator valve is bad as it does regulate when running. Thanks for the help.

  2. #2
    Forum Admin, Expert Plumber Terry's Avatar
    Join Date
    Aug 2004
    Location
    Bothell, Washington
    Posts
    14,192
    Blog Entries
    1

    Default

    You need to either install a rebuild kit to your PRV, or replace it.
    Most of the time, we replace the PRV, mainly because we can do that in one trip. You could look up the tag on your unit and see if parts are available.

  3. #3
    DIY Junior Member santhon2's Avatar
    Join Date
    Jan 2014
    Location
    Georgia
    Posts
    5

    Default

    Quote Originally Posted by Terry View Post
    You need to either install a rebuild kit to your PRV, or replace it.
    Most of the time, we replace the PRV, mainly because we can do that in one trip. You could look up the tag on your unit and see if parts are available.
    But, does the PRV shut off the water when the system is pressurized at the set psi or continue to allow creep? Or is that a different valve?

  4. #4
    Jack of all trades DonL's Avatar
    Join Date
    Mar 2011
    Location
    Houston, TX
    Posts
    3,642

    Default

    Quote Originally Posted by santhon2 View Post
    But, does the PRV shut off the water when the system is pressurized at the set psi or continue to allow creep? Or is that a different valve?

    If it is bad, It is hard to tell what it may do.

    But it will most likely still pass water, and not regulate.
    Theory only works perfect in a vacuum.

    Cyber Security Protection for Windows C:\ > WWW.WinForce.Net

  5. #5
    DIY Junior Member santhon2's Avatar
    Join Date
    Jan 2014
    Location
    Georgia
    Posts
    5

    Default

    Quote Originally Posted by DonL View Post
    If it is bad, It is hard to tell what it may do.

    But it will most likely still pass water, and not regulate.
    I guess I'm noting asking the question right. Will a NEW pressure reducing valve keep the water pressure at the set psi or do they still allow creep? When the system is fully pressurized at 50 psi does the prv hold back the additional pressure if the incoming is 150 psi or higher or do i need something else?

  6. #6
    Forum Admin, Expert Plumber Terry's Avatar
    Join Date
    Aug 2004
    Location
    Bothell, Washington
    Posts
    14,192
    Blog Entries
    1

    Default

    Quote Originally Posted by santhon2 View Post
    I guess I'm noting asking the question right. Will a NEW pressure reducing valve keep the water pressure at the set psi or do they still allow creep? When the system is fully pressurized at 50 psi does the prv hold back the additional pressure if the incoming is 150 psi or higher or do i need something else?
    That's what it does. It keeps the pressure at that setting, unless there is thermal expansion. That's why you also have a thermal expansion tank.
    You mentioned that with the water heater turned off, that the pressure climbs to 150 PSI, up from 50. You have a bad PRV

  7. #7
    Jack of all trades DonL's Avatar
    Join Date
    Mar 2011
    Location
    Houston, TX
    Posts
    3,642

    Default

    Quote Originally Posted by santhon2 View Post
    I guess I'm noting asking the question right. Will a NEW pressure reducing valve keep the water pressure at the set psi or do they still allow creep? When the system is fully pressurized at 50 psi does the prv hold back the additional pressure if the incoming is 150 psi or higher or do i need something else?

    A good working one will stop the flow of water at the preset limit.

    Is your expansion tank pre-charged properly ?


    Good Luck.
    Theory only works perfect in a vacuum.

    Cyber Security Protection for Windows C:\ > WWW.WinForce.Net

  8. #8
    DIY Junior Member santhon2's Avatar
    Join Date
    Jan 2014
    Location
    Georgia
    Posts
    5

    Default

    Quote Originally Posted by DonL View Post
    A good working one will stop the flow of water at the preset limit.

    Is your expansion tank pre-charged properly ?


    Good Luck.
    I charged the expansion tank to 60 psi, didn't help. So until i get a new prv installed should i turn off the water at night and during the day when there is no one here or just let the pressure valve on the water heater take care of it?

  9. #9
    Retired Defense Industry Engineer jadnashua's Avatar
    Join Date
    Sep 2004
    Location
    New England
    Posts
    21,383

    Default

    It's kind of unusual for the supply pressure to be in excess of 150psi, but it can happen if you're close to the pump or water tower, or sitting at the bottom of a big hill. But, if it is, check the specs on the PRV you are using. Most can handle that pressure differential, but some might require a second one in series to drop the pressure incrementally. Have you measured your supply pressure?

    To check and adjust the expansion tank, you must turn the water off, open a faucet to relieve any pressure, then you can check and adjust the pressure in the ET, otherwise, you are just checking the water pressure in the system.
    Jim DeBruycker
    Important note - I'm not a pro
    Retired Defense Industry Engineer; Schluter 2.5-day Workshop Completed 2013, 2014

  10. #10
    Jack of all trades DonL's Avatar
    Join Date
    Mar 2011
    Location
    Houston, TX
    Posts
    3,642

    Default

    I do know that 150 psi will test your plumbing for weak points.

    It will also check Appliances and water fill valves.


    I would kill water when not at home, until you can get it fixed. That should be ASAP.
    Theory only works perfect in a vacuum.

    Cyber Security Protection for Windows C:\ > WWW.WinForce.Net

  11. #11
    DIY Senior Member dj2's Avatar
    Join Date
    Aug 2013
    Location
    California
    Posts
    314

    Default

    Regulators go bad every once in a while. If you know how to fix them and have the time to do it, call the manufacturer for a kit. Otherwise, replace it, which is quicker and I bet cheaper.

    Like was said before, if you leave the house, shut the water. You don't want to come home to a flood.

  12. #12
    DIY Senior Member Reach4's Avatar
    Join Date
    Sep 2013
    Location
    IL
    Posts
    1,251

    Default

    How fast does your water pressure creep up? You maybe able to work around this for a few days by opening a cold water tap to a veryslow trickle until you get the repair.

  13. #13
    DIY Junior Member santhon2's Avatar
    Join Date
    Jan 2014
    Location
    Georgia
    Posts
    5

    Default

    Pressure creeps up pretty fast when it isn't being used, the 150psi is only what I gauged it at before the relief valve worked, it could be more. No leaks anywhere else at that pressure.

Similar Threads

  1. Replies: 0
    Last Post: 11-02-2013, 05:40 PM
  2. Water hammer bouncing pressure gauge needle AFTER pressure tank fills
    By hawkhunter in forum Pumps and Tanks Well Forum & Blog
    Replies: 10
    Last Post: 10-27-2012, 10:35 AM
  3. Super High pressure, but pressure switch appears to work properly
    By yergnov in forum Pumps and Tanks Well Forum & Blog
    Replies: 8
    Last Post: 03-03-2009, 05:14 AM
  4. 2 Houses, 2 Pressure Tanks, 1 pump, 1 controller, 1 pressure switch pro help needed!
    By betaman in forum Pumps and Tanks Well Forum & Blog
    Replies: 12
    Last Post: 05-05-2008, 05:07 AM
  5. Water in well, pump working, can't build up pressure, but doesn't lose pressure????
    By bgnotaplumber in forum Pumps and Tanks Well Forum & Blog
    Replies: 9
    Last Post: 08-20-2007, 10:32 AM

Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •