Plumbing help needed.

[jean862]

Hi Everyone,

I'm hoping someone can help me before I have to call a plumber. I just installed a new full bath in my basement and every time I run the water in the laundry area (which is also downstairs) the pipes of the new plumbing bang in the wall. It happens every time a faucet opens / close. The original plumbing that I tapped into was 3/4-inch copper. I'm using 1/2-inch copper for the bathroom.

In the bathroom, the banging also happens, when the toilet runs, the sink faucet opens and closes and also the shower faucet.

I'm not sure what I did wrong, since all pipes were secured to the studs prior to closing the walls. I've also installed arrestors on the washer machine lines and under the bathroom sink lines. The issue is still there.

I'm thinking of just re-routing the pipes and installing new plex pipes to resolve the issue.

Any help with this will be appreciated.

Thank you!

 

[Snoonyb]

Welcome.
Where are you, geographically?
My 1st suspect would be low water pressure, so, have you checked that?

 

[havasu]

Check your incoming water pressure at a spigot outside your house. They screw on the hose bib, and cost about $12. This will tell alot. Many times, you need to install sleeves where your plumbing goes through the wood. I also had a problem and was able to rectify it by draining my hot water tank, allowing air into the system, then recharging the pipes with water.

We also have a sibling forum called:

www.plumbingforums.com.

We have 15 or 20 plumbers who can help you quickly. Come on over!

 

[jean862]

Welcome.
Where are you, geographically?
My 1st suspect would be low water pressure, so, have you checked that?

Hi, Thank you for your quick response. I'm in New Jersey.
The low water pressure is attached to the main line coming in. since I have not had this issue before the new plumbing was installed, I did not mess with the pressure. also, its a 3 story house. If I touch the pressure, that might drop the pressure on the the 3rd floor.

 

[jean862]

Check your incoming water pressure at a spigot outside your house. They screw on the hose bib, and cost about $12. This will tell alot. Many times, you need to install sleeves where your plumbing goes through the wood. I also had a problem and was able to rectify it by draining my hot water tank, allowing air into the system, then recharging the pipes with water.

We also have a sibling forum called:

www.plumbingforums.com.

We have 15 or 20 plumbers who can help you quickly. Come on over!

Hi, Thank you for your quick response. I installed brackets to hold the pipes firmly and there aren't any movement in the back of the wall. I also drained all of the pipes and let air back in the system which seemed to work, but only lasted a few hours.

 

[Snoonyb]

Thank you.
Pressure is a balancing act, and can be affected by delivery, IE pressure, while also being offset by the siphoning effect of low delivery pressure, in multiple locations.

As a simple test, slightly open an upstairs faucet, then function a/any basement appliance.

Your supplier will have a recommended pressure, for your lo-cal.

 

[jean862]

Thank you.
Pressure is a balancing act, and can be affected by delivery, IE pressure, while also being offset by the siphoning effect of low delivery pressure, in multiple locations.

As a simple test, slightly open an upstairs faucet, then function a/any basement appliance.

Your supplier will have a recommended pressure, for your lo-cal.

Thank you, I will try to adjust the pressure all together to see if that resolves my issue before I go and change the piping and open walls. It sucks that I just finished and painted those walls and I had to open one already.

I installed two shut off valves where I tapped into the 3/4 pipes. just in case i needed to do anything in the new bathroom, I can just turn the water off there only.
If I close the shut off valves halfway - would that limit the pressure on the pipes to stop the banging? or the I should turn down the pressure from the main inlet from outside?

 

[havasu]

Many times the sound is a reverberation from just a loose washer in one of your angle stops.

 

[Snoonyb]

As previous suggested;"As a simple test, slightly open an upstairs faucet, then function a/any basement appliance."

What I inadvertently omitted was, just slightly, open a cold water faucet.
This action may cause the water flow to decrees, or stop, in the upstairs faucet, creating a syphon. So after activating a/any basement appliance, reporting those results, and returning to the upstairs faucet, you notice any evidence of sputtering or splashing, the siphon will be confirmed, as well as low water pressure.

"or the I should turn down the pressure from the main inlet from outside?"

Why would you even consider lowering the pressure, that you haven't determined the value of?

 

[jean862]

As previous suggested;"As a simple test, slightly open an upstairs faucet, then function a/any basement appliance."

What I inadvertently omitted was, just slightly, open a cold water faucet.
This action may cause the water flow to decrees, or stop, in the upstairs faucet, creating a syphon. So after activating a/any basement appliance, reporting those results, and returning to the upstairs faucet, you notice any evidence of sputtering or splashing, the siphon will be confirmed, as well as low water pressure.

"or the I should turn down the pressure from the main inlet from outside?"

Why would you even consider lowering the pressure, that you haven't determined the value of?

Hi, I did the test this morning but it doesn't syphon. While the water is on upstairs, the noise in the wall was hardly noticeable once the faucet was opened and closed.

I ordered a pressure gauge from Amazon and should have it today. As Havasu stated to checked the pressure, I'm going to attempt to adjust that today.
I also bought two new pressure reducing valves to also install in the lines that I tapped into.

I truly appreciated everyone's help with this. Hopefully it gets resolved after adjusting the pressure from the main valve for the house and I wont have to touch anything else. (After all, my wife has always complained about how the water pressure in the house is so high).

 

[Snoonyb]

The reduction in the banging, with the upstairs faucet open is an indication that the supply pressure is low.

So, BEFORE YOU DO ANY ADJUSTING OF THE PRESSURE, CALL YOUR SUPPLIER AND ASK THEIR SUPPLIED PRESSURE, FOR YOUR AREA.

 

[jean862]

The reduction in the banging, with the upstairs faucet open is an indication that the supply pressure is low.

So, BEFORE YOU DO ANY ADJUSTING OF THE PRESSURE, CALL YOUR SUPPLIER AND ASK THEIR SUPPLIED PRESSURE, FOR YOUR AREA.

Thank you Snoonyb. I'll reach out to the city now to see if they can help answer that question.

 

[jean862]

The reduction in the banging, with the upstairs faucet open is an indication that the supply pressure is low.

So, BEFORE YOU DO ANY ADJUSTING OF THE PRESSURE, CALL YOUR SUPPLIER AND ASK THEIR SUPPLIED PRESSURE, FOR YOUR AREA.

Hi,

I just re-checked this.
And yes, the pipes still bang as loud as they were originally. The first time, I probably slowly closed the faucet which was probably why I did not notice the bang. but I just rechecked it, and they do still bang.

 

[PJB12]

Two quick things to try:
A) Loosen the pipe straps where the banging is a bit. Even cork tape under the pipe and strap helps. Sometimes when the pipes get a "slug" from another outlet closing, if they can move a bit it helps.

B) Check with the manufacturer of the water hammer arrestors to be sure they are the correct size & orientation. You may have to increase size. Also, some can e mounted in any position- some must be vertically. Sioux Cheif has a good chart online.
You mentioned draining the pipes, creating a temporary water hammer arrestor, helped temporarily. This makes me think water hammer arrestor size & placement are good places to focus.

Paul
PS: Low pressure probably isn't a problem. We have low 38-40 PSI-G and had hammer from fast closing valves, especially the Grohe GroTherm faucet & laundry machine solenoids. Diffrerent water hammer arrestors & loosening pipe straps solved it.

 

[jean862]

I took the pressure this morning and it was reading 70 psi on the cold side. I dropped the whole house to 45 psi, but the pipes behave the same. at this point, I'm just going to redo the plumbing and remove the pipes from the back of the wall.

 

[PJB12]

I took the pressure this morning and it was reading 70 psi on the cold side. I dropped the whole house to 45 psi, but the pipes behave the same. at this point, I'm just going to redo the plumbing and remove the pipes from the back of the wall.

That sounds like the quickest thing to try first, but be sure to hold one of the pipes lightly while someone does whatever causes the hammer. Even with the pipes loose, it's important to be sure there's no slamming going on. (Just my thought on the situation.)

 

[ekrig]

Just out of curiosity, do you have an expansion tank on your water heater? If so, you should also make sure that it is working properly. Other than the pressure regulator at the intake, that's the other main pressure regulating device in the house, compensating for the expansion of the hot water in the water heater. They occasionally need to be reinflated to match the intake base pressure.

 

[PJB12]

Jean862, Ekrig mentioned an expansion tank. If you have a swing or atmospheric check valve on the system, as required in many localities, Ekrig's suggestion is really, really important!

And, often you need a check valve if you have an expansion tank. The meter can actually record more water used than you actually consumed due to back-and-forth swings. Here's a short article: https://www.amwater.com/resources/PDF/water-quality/Cross-Connection-Expansion-Tanks.pdf

If you do install an expansion tank, a good idea is to install an isolation valve with a drain port at the top of the tank.
You can put a NPT ball valve & remove the tank to test, or use an Isolation Valve with Drain Port.

By using a valve with a drain port, you can close the valve & release the water pressure on the tank's diaphragm. This will let you test the air cushion pressure without removing the tank. (Always release the pressure or remove the tank to test.)

A couple of examples of the valve types are below. The one with the hose thread is about $25.00 and the one with the weep cap is about $8.00. Supply House Com sells both, as do plumbing wholesalers. (Make sure it is rated for potable water. Some for hydronic have lead.)

Paul

How Expansion Tanks Work:
The expansion tank is a hollow cylinder. (Picture the tank mounted vertically, water connection at the top)
The tank has a diaphragm inside. Below the diaphragm, there is an air cushion. When the pressure is low, the diaphragm is crowned at, or near, the top of the tank.
When water pressure pushes on the diaphragm, it moves down against the pressure of the air cushion.
Picture the air cushion like a door with "X" pounds of force required to open it. The water pushes on the door. When pressure is above "X" pounds, water goes through the door into the tank. When the water pressure pushing on the door drops below"X", the door closes, sucking the water back into your piping. The diaphragm moves back to the top of the tank.

 

[PJB12]

Just out of curiosity, do you have an expansion tank on your water heater? If so, you should also make sure that it is working properly. Other than the pressure regulator at the intake, that's the other main pressure regulating device in the house, compensating for the expansion of the hot water in the water heater. They occasionally need to be reinflated to match the intake base pressure.

Thank You For Posting this Important Information!
Paul

 

[jean862]

Thank you Everyone for taking the time to help me with this.

I added two water arrestors on the line under the sink and another two between the lines in the wall.
I also added two water pressure reducer valves where the lines are connected from the existing lines of the house.

I dropped the pressure very low enough to use the faucet and the shower without any issues. I kept the cooper piping since I do not trust PEX. There is still a little noise on the hot water side only but its barely noticeable. The cold water is no longer making any noise so that's a plus. also, when I turn faucets around the house the pipes in the shower downstairs no longer bang.

So this problem is now isolated in the bathroom only and its only the hot water line that makes a small bang.

My wife wanted me to start closing the walls, so I started closing the walls today so I can start cleaning the area. I hope the noise from the hot water goes away on its own, or I might just drop the pressure a little bit more.

I think I'm just going to leave it like that, since the house 3 bathrooms already and this is a 4th one, for anyone that decides to stay over because there is a bedroom downstairs which now opens into the bathroom.

If anyone has any other suggestions, I will gladly take it. In the meanwhile, Thank you so much again for taking the time to help me with this. Stay well and God bless.