Home Water Pressure vs Flow Issue

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ShortPant

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Hello all! First time poster, here. I've searched the forum and couldn't find my situation although I may have missed it.

I just moved into a house built in 2011. City Water. During the home inspection, the inspector noticed a reduction in pressure/flow when the water is in use, especially when more than one outlet is in use. The previous owners wouldn't address the issue, as "it's always been that way" was the response. They never had this issue looked at. They did knock off a few bucks though. :)

Water meter valve at the street is all the way open.
Shut-off valve in the house is all the way open.
Wilkins NR3 PRV installed.
Stagnant pressure at outside faucet is approximately 80 psi.

When using any single outlet: Sinks, showers, washing machine (all hot AND cold), toilets, exterior faucets, the water pressure drops quickly below 10 psi. It takes a WHILE (at least 20 - 30 mins) for the pressure to build back up. Only one outlet/faucet can be used effectively at any time.

Of course, I'm looking at the PRV, but I don't know a lot about them. I've tinkered with it to see if adjusting the setting would affect the issue. It did not. The initial flow would be better due to higher presure, but again, it would drop off. Looking online, I see there's a strainer screen inside the PRV. I'm HOPING this is blocked/restricted, as my next step is to swap the PRV.

All this being said, am I missing something else that may be the culprit? No one else in the neighborhood of close/cookie cutters has this issue so I'm assuming it's not outside the house. Could a somewhat "properly operating" PRV still be causing this problem?

Thanks in advance!!
 

wwhitney

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Could you clarify if all your pressure readings are taken at the hose bibb, and whether the hose bibb is before the PRV?

If yes and yes, the part about "it takes a WHILE (at least 20 - 30 mins) for the pressure to build back up" is very strange. And it would suggest that the obstruction, whatever it is, is upstream of the hose bibb, e.g. debris in the water lateral or something.

Cheers, Wayne
 

ShortPant

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Hi Wayne, Thanks for you reply. My apologies, but I'm not sure what you're calling the "hose bibb." I'm checking the water pressure at an outside hose faucet, which is downstream, after the PRV. My routing would require me to remove the PRV (inside my garage of a 2 story house) to get a reading before the PRV. I'd hope to just remove the PRV once. lol
 

wwhitney

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hose bibb = hose faucet = hose spigot.

If the only thing upstream of the hose bibb is the PRV, the water lateral, and the water meter, the problem is by far most likely to be the PRV. So you can either disassemble it and clean/inspect it, or just replace it. I'd start with disassembly, although if you any concerns about your ability to properly reassemble, I could see jumping to replacement.

BTW, I don't have hands-on experience with PRVs. Someone else might be able to come along and say "oh that 20-30 minutes to restore pressure symptom means this particular part inside needs replacing" or something like that.

Cheers, Wayne
 

ShortPant

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Great input and information. My fingers are crossed. I've seen kits to rebuild this PRV that are the same cost as the PRV, although I'm sure I could do it. This PRV is discontinued anyway and must be for a reason, right? I appreciate your feedback and will watch for additional input, if any. I'll follow up in a few days, following the PRV replacement. Thanks again!
 

Reach4

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I've seen kits to rebuild this PRV that are the same cost as the PRV, although I'm sure I could do it. This PRV is discontinued anyway and must be for a reason, right?
Typically the discontinued unit is replaced by a compatible unit minus most of the lead.

https://www.zurn.com/products/water-control/pressure-reducing-valves/rk34-nr3xl says it does nr3 and nr3xl both.

New PRV would probably require more actual plumbing change. Rebuild could probably leave the existing PRV in place. I have no relevant experience.
 

ShortPant

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Both scenarios crossed my mind. The "ease" of gutting it in place, vs the confidence of replacing the whole valve. They appear identical. I'll address this in my follow up, hopefully in a positive manner. :)
 

ShortPant

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Once I realized there's a screen inside, the thought of checking that did cross my mind. Honestly, I hope the chances are high that this is the cause. However, I only want to do this once. I'm already expecting to get wet doing this as the valve is in my garage, about 6 feet high. I'm assuming I'll need to try and drain all the lines from upstairs (at least) before opening this valve/line at its location.
 

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Reach4

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Which way is the flow-- up or down?

Draining that is not going to be easy .

A wet-dry vacuum may help.
 

ShortPant

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It flows up. I'm hoping that after closing the shut off valve I can open everything upstairs while opening outside spigots to get the majority of the lines clear.
 

Reach4

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It flows up. I'm hoping that after closing the shut off valve I can open everything upstairs while opening outside spigots to get the majority of the lines clear.
Either close the valve supplying the WH, or draw down the WH to below the PRV. If you will drop water level, turn off the electric water heater first.


Open lower spigots. Have you no cold spigot lower than the hose spigots? If no, turn off the WH. Leave the WH valve open. Drain the WH.

An air compressor could help move some water.

If you do replace the PRV, consider adding a boiler drain valve between the ball valve and the PRV. That would help drain in the future, and would let you temporarily attach a garden hose thread pressure gauge for future troubleshooting.

Maybe put an inflatable pool or a garbage can under the PRV when you open that up.
 

Jadnashua

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What material is the supply line coming into the house made out of?

If you're lucky, it's just the inlet screen is clogged, but the PRV probably needs a rebuild or replacement. If you were to pay someone to do it, the labor to rebuild (if they can find a kit) plus the parts cost and potential liability means they would much prefer to just replace it with a new one, and the end cost would likely be less. WOrst case, it could be that the line is crimped somewhere, maybe from a truck driving over the lawn, or a tree root, of who knows what.

If the inlet pipe is galvanized steel, that may be even worse, as generally, that means replacing the whole line from the street. Any galvanized pipe or fittings should be replaced with brass, or copper, or stainless steel. Their insides could be all constricted with rust. It sounds like you have a huge volume issue, and that generally implies a restriction somewhere (that could be internal to the PRV, but may not be). SO, the low hanging fruit is probably the PRV, unless you tell us you have galvanized piping somewhere in the system.

Also note, that you will want to check out your expansion tank (ET), and if you don't have one, you WILL need to install one for proper operation. A PRV acts like a check valve. Heating water causes it to expand. Water is not compressible, and water pipes are pretty rigid, so any expansion immediately becomes an increase in pressure. That can rise rapidly, and it will leak out the weakest point. That often is a toilet fill valve, and you may not notice, but it could be any faucet that can leak, and worst case, it's the water heater's safety valve, that SHOULD open when the pressure gets to 150-psi unless the pressure was released somewhere else at a lower value. The pressure would get there fairly quickly, and if that safety valve didn't open, it could damage things. The hoses to faucets, washing machines, water coolers, dishwashers, etc., don't really like high pressure, so keeping it in check is important.
 

ShortPant

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Thanks Jadnashua! I don't have any galvanized lines to the best of my knowledge. I've only seen PEX used where anything is exposed, except for some copper lines only immediately in/out of the water heater. I'm not 100% positive, but this being a 10 year house/neighborhood, I don't feel anything else would have been used for the lateral line either. I did have a look at the lateral line meter and shut-off, but didn't dig around it enough to verify the line material. Understanding your point though, if this isn't the PRV, possibly something happened very early on during construction that pinched the lateral line which is my worst fear. I'm hoping that some pressure/flow analyzing can easily be done when I have the PRV out, by attaching a hose or something, since it's inside the garage/sheetrock area. I'd like to be able to open the shutoff valve while the PRV is out to "flush" and test the inlet line without PRV restriction.

I do have an expansion tank and have been researching the proper servicing of said tank. It's reading about 47 psi and I will be checking again for proper servicing.

Thank you for your feedback. I plan to do my water works in the next few days and will post my findings.

Many thanks!!
 

Jeff H Young

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basic steps to go through you have plenty of pressure but no volume that means blockage , broken valve , pinched line stuff like that. another check would be remove regulator and turn water on I'd put a bucket upside down see what happens if it just blasts like crazy and doesn't slow down then the section from meter to the house is probably good. Are there any tees between meter and regulator to check flow? irrigation or whatever? might check those . but between all the comments your wheels should be turning on ideas
 

ShortPant

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UPDATE: I changed the PRV last night. Luckily I had very little water spillage, like only a few cups. I didn't notice any blockage inside the original PRV, or around the screen. I did do a quick "purge" of the input line, by duct taping a hose to the line, and opening the main shut-off valve. I got enough flow that I'm satisfied that side of the system is good. lol I sprayed more water into the area from doing that than when I cracked opened the PRV connections. So I couldn't not change the PRV even though I didn't see any obvious problems with the original, so I have a new PRV valve in place. It was set to 50 psi from the manufacturer and I verified this with a gauge. After working out all the air to the faucets I had opened to drain, ultimately, I can see a good improvement, to the point where I'm now satisfied with the system. I have the pressure set to 70, and the flow is much better than before. Maybe it was just a bad PRV?

However....

I have a new problem. The expansion tank doesn't seem to be holding any air pressure. My air pressure gauge doesn't pick up anything. I "serviced" the tank using 70 psi regulated air pressure since the gauges (I tried more than one gauge) weren't picking up any pressure, yet, it didn't seem to be taking any air. No evidence of air seeping when I press the core inside the air valve. The air valve core springs/seats but no evidence of any pressure in the tank. What did I do wrong?
 

Reach4

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The expansion tank doesn't seem to be holding any air pressure. My air pressure gauge doesn't pick up anything. I "serviced" the tank using 70 psi regulated air pressure since the gauges (I tried more than one gauge) weren't picking up any pressure, yet, it didn't seem to be taking any air. No evidence of air seeping when I press the core inside the air valve. The air valve core springs/seats but no evidence of any pressure in the tank. What did I do wrong?
One possibility is that you did not press the pin into the Schrader valve enough. While you applied 70 psi of air, what was the effect on the water pressure? If that water pressure did not rise to 70 psi, I can only think that the air was blocked at the Schrader valve. Maybe the Schrader valve is stuck.

A thermal expansion tank should normally be empty of water, and with a non-leaking PRV should only start accepting water as the water expands due to temperature. With a 50 psi PRV, you would set the air precharge to about 51 psi.
 

ShortPant

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Have a look at the picture. The expansion tank is located in a pretty awkward location above the water heater, and with it's positioning I don't see how it could ever not have water in it. I only have maybe 2 inches of clearance to even access the Schrader valve, but I was able to press the pin with an angled scribe and feel it move, and spring back. I can barely maneuver a gauge onto the valve. I can get the air servicing line on with no problem though. I don't know how the internals of the tank are designed so I don't know how/with what the Schrader valve could be blocked.
 

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Themp

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Since you set your PRV to 70 psi, you want to turn off the water and release the pressure in your system by opening one faucet and then try and set the pressure to 70 psi in the expansion tank using the Schrader valve. If you cannot get that to set to 70 psi then some thing is wrong with the expansion tank, so I would just replace it at this point. Then you have a new PRV and tank at this point forward.

https://www.bobvila.com/articles/expansion-tanks/
 
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