Pressure Build Up

[Mudman]

I have an issue that came up over the past year that seems to be finally creating a problem that I need to address. I have a 2 story house and only in one faucet in the downstairs I've developed a pressure build up it appears. When I turn this faucet on , and if it's been unused for a small period of time, I get a release of pressure for a second and then it operates normally. I wasn't too worried about it until now, but I've developed drip leaks whenever I turn on this faucet on. Not sure but I think that it started to happen about the time I did a bathroom remodel upstairs, part of which was replacing the rough in valve body for the shower in which i needed to cut the old valve body out and solder in the new one. The only thing that I could think is that maybe the pressure is being caused from air in the line??

Any ideas?

Thanks!

 

[CT18]

That should not happen as all pressure should be the same. What is the house pressure. It may be getting air in somewhere.

 

[Mudman]

That should not happen as all pressure should be the same. What is the house pressure. It may be getting air in somewhere.

What is the proper way to check the house pressure and what should I be looking for? Is there a way to check for air getting into the line?

 

[jeffmattero76]

You can buy a gauge at a big box or supply house for less than $10. It would screw on to your hose bibb. Turn the water 9n and it will read the pressure.

What is the proper way to check the house pressure and what should I be looking for? Is there a way to check for air getting into the line?

 

[RenewDave]

Thermal expansion could be a factor. If you can pinpoint when it happens, that would help.

 

[Mr_David]

If you are having a pressure build up in the system it is occurring in the entire system. It may only be noticeable at that one fixture.
Thermal expansion could be the issue as RenewDave suggested.
A bad Pressure Reducing Valve can also be the cause. It leaks by when all fixtures are closed and regulates desired pressure only when there is water flow.
To eliminate Thermal expansion, turn off power to water heater if electric or dial down thermostat on gas heater to low.
Check pressure with gauge at a hose bib. record it.
Open a faucet to relieve any build up. record it.
Wait and watch gauge.1 minute or 1 hour. What ever it takes. Does the pressure increase?
Then you probably have a bad PRV.
If you have a working water shut off valve that works 100%, NOT 99% you can turn that off to see if you system leaks.
The pressure on gauge should hold if you have no leaks in the system.
It that is true and you turned WH back on, with main valve still closed, heater cooking will cause thermal expansion and the pressure should start to increase on gauge.

 

[Mudman]

If you are having a pressure build up in the system it is occurring in the entire system. It may only be noticeable at that one fixture.
Thermal expansion could be the issue as RenewDave suggested.
A bad Pressure Reducing Valve can also be the cause. It leaks by when all fixtures are closed and regulates desired pressure only when there is water flow.
To eliminate Thermal expansion, turn off power to water heater if electric or dial down thermostat on gas heater to low.
Check pressure with gauge at a hose bib. record it.
Open a faucet to relieve any build up. record it.
Wait and watch gauge.1 minute or 1 hour. What ever it takes. Does the pressure increase?
Then you probably have a bad PRV.
If you have a working water shut off valve that works 100%, NOT 99% you can turn that off to see if you system leaks.
The pressure on gauge should hold if you have no leaks in the system.
It that is true and you turned WH back on, with main valve still closed, heater cooking will cause thermal expansion and the pressure should start to increase on gauge.

OK I purchased a pressure gauge and I have a couple of questions;

1. When i turn down/off the water heater do I need to let the system cool down before performing the test?
2. I know there is a PRV on the water heater, is this what you are referring to?

thx

-Kevin

 

[jeffmattero76]

Simply hook the pressure gauge to your hose bibb, and then turn that hose bibb on fully. Read the gauge. That will tell you what your water pressure is.

The thing on the side 8f the water heater is a pressure RELIEF valve. It's function is to open and let water out of your water heater if the heated water exerts too much pressure, typically because the temperature is set too high.

The pressure REDUCING valve will likely be found on the pipe that brings water into your house from the street. It kind of looks like a bell. Google it if you need a picture. They usually are adjustable by turning a screw one way or the other. I believe you want your water pressure to be around 50. 8f adjusting the pressure reducing valve doesn't change the reading on the new gauge you bought, then you will have to replace the pressure reducing valve. Hope that helps.

 

[Diehard]

1. Do you have a pressure reducing valve on your water service?
2. When operating the downstairs faucet, does the pressure build happen in either HOT or COLD sides?
3. What do you mean by pressure build up/release of pressure? The water comes out faster or are you talking about air blasting out?
4. "unused for a small period of time"... So like what's a small period of time? Like 5 minutes, or days?
5. "developed drip leaks whenever I turn on this faucet on"...So when you turn on the downstairs faucet, then shut it again, it drips. How long does it drip for? You make it sound like it drips only when you open the faucet then shut it and then dripping must stop, otherwise it wouldn't repeat itself. If you know what I mean.

 

[JeffL]

OK I purchased a pressure gauge and I have a couple of questions;

1. When i turn down/off the water heater do I need to let the system cool down before performing the test?
2. I know there is a PRV on the water heater, is this what you are referring to?

thx

-Kevin

I'm pretty sure no one is talking about a PRV on the water heater. There should be a PRV where the main water line enters the house. They look like this: https://images.homedepot-static.com...ressure-regulators-3-4-lf25aub-z3-64_1000.jpg They don't last forever.

The hose bib they are referring to is not the one for draining the water heater. It is the outside hose faucet, just be sure it's on the house side of the PRV, otherwise you'll be measuring the street water pressure.

 

[jwwing]

The PRV will be just after the water meter (at least it is in my case). As others have already indicated, the pressure you see must be coming from a build-up of pressure, which the PRV can allow to happen, but it is not likely. But then neither is a pressure build-up.

I am assuming that your pressure release is in the form of water and not air - it makes a big difference. If it is air, you are suffering some kind of pressure reflux that is causing air to be introduced into the system. The air from your rework should have escaped by now. You could have a pressurized bladder somewhere that is used to control expansion that might be leaking air into the system, but it too would only do so for a short time.

 

[Diehard]

Too many assumptions and not enough detailed information on conditions and symptoms, let alone the his main concern, which is the "drip leaks whenever I turn on this faucet on".

 

[JeffL]

The PRV will be just after the water meter (at least it is in my case).

My water meter is under ground under a cover on the parkway, and the PRV is in front of the house where the main water piper enters. It can also be in the basement if the house has one.

A faucet drip is usually caused by a bad faucet washer or faucet seat. It's my understanding that too high of a water pressure from a bad PRV (or no PRV) can also cause a drip.

 

[jwwing]

My water meter is under ground under a cover on the parkway, and the PRV is in front of the house where the main water piper enters. It can also be in the basement if the house has one.

Yes, arguably the same as what I said, relative to the whole house. Mine is 600 ft away from the house, but next to the water meter because it was installed by the water company at their expense, not by someone working for me or the home owner at the time - but it could be anywhere in between - meaning not somewhere in the plumbing of the house - somewhere in its service entry. I probably should have said it that way. Stating where it is located was intended only to help locate it if there is one - the OP was apparently confused about what a PRV is.

As far as dripping, it depends on the design of the shutoff mechanism. Spring loaded mechanisms are subject to small particles and to increasing pressure, but if they are made right, the pressure will help them hold the seal tightly. The older style of shutoff relies on brute strength and results in leaks when a weaker person tries to shut it off. Once it is shut off by someone strong, the material is damaged and subject to leaking even more so especially when a weaker person operates it the next time. A weaker person is someone like a person suffering from arthritis in the hands, a child, a woman as compared to a person with more powerful hands. That does not mean that the older style devices will necessarily fail in such an environment, but are prone to do so. The newer style shut off mechanisms use clever designs to avoid the need for the flat rubber against a ridge of soft metal that the old ones used. If the faucet that is leaking is an old style one, it could leak without extra pressure.

I think that 'diehard' is right - too many assumptions and I just made a few more. LOL

 

[Mr_David]

OK I purchased a pressure gauge and I have a couple of questions;

1. When i turn down/off the water heater do I need to let the system cool down before performing the test? No, expansion occurs only when heat is being applied to the water.
2. I know there is a PRV on the water heater, is this what you are referring to?

thx

-Kevin

 

[Mr_David]

1. Do you have a pressure reducing valve on your water service?
2. When operating the downstairs faucet, does the pressure build happen in either HOT or COLD sides?
3. What do you mean by pressure build up/release of pressure? The water comes out faster or are you talking about air blasting out?
4. "unused for a small period of time"... So like what's a small period of time? Like 5 minutes, or days?
5. "developed drip leaks whenever I turn on this faucet on"...So when you turn on the downstairs faucet, then shut it again, it drips. How long does it drip for? You make it sound like it drips only when you open the faucet then shut it and then dripping must stop, otherwise it wouldn't repeat itself. If you know what I mean.

All good questions. # 5 I had to go back and re-read the 1st post. . I missed that.