Checking Water Pressure - Plumbing - DIY Home Improvement | DIYChatroom
Advertisement


Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Plumbing

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Search this Thread
Display Modes
Old 01-01-2016, 07:22 PM   #1
Newbie
 
Join Date: Oct 2015
Posts: 17
Rewards Points: 34
Default

Checking Water Pressure


Good Evening,

I have an under counter water filter installed that is about 1.5 years old. I recently changed the filter cartridge, and found that the housing was cracked. To determine if this was a defective product or if I had a water pressure problem, I purchased a water pressure gauge from a home improvement store.

With all faucets turned off, pressure read 85. With a faucet running, it read 60.

I adjusted pressure reducing valve. Now with all faucets turned off, it still read 85. With a faucet on, though, it read 40, and the pressure coming out of the faucet was obviously reduced. That said, when I first turned on a faucet, the pressure would be higher, and then quickly drop off to the noticeably low pressure.

Does this indicate a faulty pressure reducing valve or a bad pressure gauge, or something else? I would like to set my pressure at 60.

Thanks for the input.
oldave79 is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 01-01-2016, 07:25 PM   #2
Member
 
Join Date: Mar 2013
Location: Ohio
Posts: 5,653
Rewards Points: 1,852
Default


That would be a sign of bad PR valve. Make sure though that the outside faucet your testing at is not piped in the inlet side of the PR valve. It occasionally is done this way to allow higher pressures for a lawn sprinkler.
Ghostmaker is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 01-01-2016, 07:28 PM   #3
Member
 
raylo32's Avatar
 
Join Date: Nov 2006
Location: Maryland (DC 'burbs)
Posts: 2,189
Rewards Points: 1,450
Default


Could possibly be a bad regulator. Only way to be sure is to check the pressure upstream of the regulator and compare to downstream. 85 sounds typical of city supplied pressure and if your regulator fails it can pass that through. I had this happen a couple years ago and had to rebuild my regulator.
__________________
Live long and prosper.
raylo32 is offline   Reply With Quote
The Following User Says Thank You to raylo32 For This Useful Post:
oldave79 (01-01-2016)
Sponsored Links
Advertisement
 
Old 01-01-2016, 08:03 PM   #4
Newbie
 
Join Date: Oct 2015
Posts: 17
Rewards Points: 34
Default


So even though adjusting the reducing valve caused the pressure to drop with a faucet running, it would still indicate that the PRV isn't working correctly?

PRV (and house) is only 2 years old. Do they normally fail that quickly? Guess I need to get a plumber out to check it.
oldave79 is offline   Reply With Quote
Old 01-01-2016, 10:20 PM   #5
Member
 
Join Date: Mar 2013
Location: Ohio
Posts: 5,653
Rewards Points: 1,852
Default


Yes. The PR valve should reduce pressure when water is not running.

Because that is all it allows to enter the house.
Ghostmaker is offline   Reply With Quote
The Following 2 Users Say Thank You to Ghostmaker For This Useful Post:
jmon (01-01-2016), oldave79 (01-01-2016)
Old 01-01-2016, 10:24 PM   #6
Member
 
Join Date: Nov 2012
Posts: 4,821
Rewards Points: 3,208
Default


Quote:
Originally Posted by oldave79 View Post
PRV (and house) is only 2 years old. Do they normally fail that quickly? Guess I need to get a plumber out to check it.
Sometimes a piece of debris gets stuck in the incoming screen which may affect the way it works. This can be easily checked and cleaned.

Do you have an expansion tank on the water heater? If so, check and make sure it's set at the proper psi and not water logged.

If you can't get it figured out, your suggestion of getting a plumber to check it out is a good option. Hope you get it figured out soon. Happy New Year.
jmon is online now   Reply With Quote
The Following User Says Thank You to jmon For This Useful Post:
oldave79 (01-01-2016)
Old 01-01-2016, 10:57 PM   #7
Newbie
 
Join Date: Oct 2015
Posts: 17
Rewards Points: 34
Default


Thanks! I will probably see if I can get someone out next week to look at it. I'm pretty handy, but my plumbing knowledge is more or less limited to changing fixtures and supply lines, though I suspect if I watch what the pro does to fix the situation, I may be able to rectify it myself should it reoccur in the future.
oldave79 is offline   Reply With Quote
Old 01-02-2016, 06:57 AM   #8
Member
 
raylo32's Avatar
 
Join Date: Nov 2006
Location: Maryland (DC 'burbs)
Posts: 2,189
Rewards Points: 1,450
Default


I doubt the reg would fail in 2 years but I guess possible. Getting grit in it more likely.

As for the expansion tank.... if you have one and it is working properly the pressure rise after shutting a faucet may be slow and will depend on how fast the reg is leaking by, but will ultimately maximally compress the bubble and reach city pressure. IOW expansion tanks are really good for normal transients from water heaters and such but when a reg fails and leaks by you have an unlimited transient that even the biggest expansion tank can't cover.

BTW, replacing a reg isn't that difficult if you do decide to do it. The easiest way is to find the exact same reg unit and replace in kind. If it is difficult to remove the old one do what I did, just spin off the cap and swap the internals from the new to the old. 5 minutes and you don't even need to dust off your pipe wrenching, soldering, or gluing skills.

I also installed a permanent gage downstream of my reg in the port that the plumber used to set the reg initially so I can always look and see what my house side pressure is doing. I am not sure why they don't require them to be there since it is really hard to spot a bad reg without it. Without the gage you need to suspect you have a problem and get a gage to go look. Now I just glance at it whenever I am in my utility/laundry room.
__________________
Live long and prosper.

Last edited by raylo32; 01-02-2016 at 07:03 AM.
raylo32 is offline   Reply With Quote
The Following User Says Thank You to raylo32 For This Useful Post:
oldave79 (01-02-2016)
Old 01-02-2016, 07:22 AM   #9
Property Mgt/Maint
 
Join Date: Mar 2015
Location: Upstate NY
Posts: 6,469
Rewards Points: 8,184
Default


Quote:
Originally Posted by oldave79 View Post
With all faucets turned off, pressure read 85. With a faucet running, it read 60.

I adjusted pressure reducing valve. Now with all faucets turned off, it still read 85. With a faucet on, though, it read 40, and the pressure coming out of the faucet was obviously reduced. That said, when I first turned on a faucet, the pressure would be higher, and then quickly drop off to the noticeably low pressure.

Does this indicate a faulty pressure reducing valve or a bad pressure gauge, or something else? I would like to set my pressure at 60.

Thanks for the input.
After making a down PR adjustment the line pressure downstream is still high until relieved by opening a faucet valve.

After the PR adjustment and you relieved the pressure by opening a faucet valve did the line pressure go back up?
__________________
[political signature removed]
Yodaman is offline   Reply With Quote
The Following User Says Thank You to Yodaman For This Useful Post:
oldave79 (01-02-2016)
Old 01-02-2016, 10:21 AM   #10
Newbie
 
Join Date: Oct 2015
Posts: 17
Rewards Points: 34
Default


Raylo, the pressure rise after shutting off the faucet occurred within a few seconds. So it sounds like I may have a faulty expansion tank then too. Thanks for the insight on pressure reducing valves.

Yodaman, when I adjusted the pressure down, the pressure dropped significantly with a faucet open, but once the faucet was closed, it returned to 85, regardless of where I set the pressure. Very strange.
oldave79 is offline   Reply With Quote
Old 01-02-2016, 01:02 PM   #11
Newbie
 
Join Date: Oct 2015
Posts: 17
Rewards Points: 34
Default


I also checked the pressure on the expansion tank, and there was no air charge in it at all. I guess the builder used really lousy materials and/or did a poor job of installation for things to be failing this quickly.
oldave79 is offline   Reply With Quote
Old 01-02-2016, 01:51 PM   #12
Property Mgt/Maint
 
Join Date: Mar 2015
Location: Upstate NY
Posts: 6,469
Rewards Points: 8,184
Default


Quote:
Originally Posted by oldave79 View Post
Yodaman, when I adjusted the pressure down, the pressure dropped significantly with a faucet open, but once the faucet was closed, it returned to 85, regardless of where I set the pressure. Very strange.

Not strange. This is what I would expect with a bad PR. The pressure is reduced when a valve is open. Much like a shower might be affected by someone flushing the toilet. The line pressure drops when valves are opened. When all are closed pressure should return to the set pressure. In your case the PR is not reducing the line pressure. Time for a new PR or rebuild.
Good luck
__________________
[political signature removed]
Yodaman is offline   Reply With Quote
The Following User Says Thank You to Yodaman For This Useful Post:
raylo32 (01-03-2016)
Old 01-02-2016, 02:14 PM   #13
Newbie
 
Join Date: Oct 2015
Posts: 17
Rewards Points: 34
Default


Thanks. The insight and consensus here has convinced me that the PRV is indeed not working correctly. I'm going to get a plumber out here next week to rectify and hopefully avoid the larger problems that can come with high pressure.
oldave79 is offline   Reply With Quote
Old 01-02-2016, 03:59 PM   #14
Member
 
Join Date: Dec 2015
Posts: 99
Rewards Points: 114
Default


A pressure increase due to a faulty expansion tank is a result of heating water. It would take longer then a few seconds for your water heater to bring the pressure in the house up so don't use that as a gauge for whether or not your expansion tank is bad. If you want to see for yourself turn your water heater off or to pilot and retest, it will not affect the pressure readings.

It is normal for pressure to drop when a faucet is opened. This alone is not indicative of a problem. A pressure drop of 25lbs however is more then normal, something isn't right. What type of water service do you have? Is it galvanized? I doubt it is if the house is that new but perhaps if it was a remodel they tied back into the old service. If it is galvanized it may be rusted closed so much that a drop that large is normal and the only way to fix it is a new water service. More likely your PRV is bad, has a clogged screen or something is stuck in it. Are all your main valves fully open? Is their anything else before the PRV, a wye strainer perhaps that may be clogged?

85lbs of pressure isn't that bad. Find out what kind of pressure you have in the street. If it's only 85psi I wouldn't bother with a PRV unless you are required to have one there.

Last edited by 2x_Tom; 01-02-2016 at 04:01 PM.
2x_Tom is offline   Reply With Quote
Old 01-02-2016, 05:01 PM   #15
Newbie
 
Join Date: Oct 2015
Posts: 17
Rewards Points: 34
Default


My plumbing is PEX. Only one main valve and it's open. From the comments here, it sounds as though the PRV is malfunctioning. Code here requires a PRV, and I have water filters installed that call for a max 75 PSI, one of which I noticed was cracked while I was servicing it, which is what generated the concern.
oldave79 is offline   Reply With Quote
Sponsored Links
Advertisement
 
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Intermittent Low Water Pressure Mystery bmbouter Plumbing 5 10-27-2015 04:54 AM
Increased Water Pressure mike123333 Plumbing 18 04-11-2015 05:59 PM
Low water pressure (hot water only) - temp fix when I shut off water supply to tank skilletrx Plumbing 5 11-15-2012 07:37 AM
Check valve gimaarob Plumbing 13 10-27-2011 10:13 PM
bad valve washing machine?? drdon51 Plumbing 6 06-29-2009 01:02 PM




Top of Page | View New Posts