Rattling pipes on 2nd floor Bath ONLY when HOT water on. Plumber wants $600

[TNguy]

Hello folks!

Please help me figure out the least expensive way to solve this.

When open the shower's hot water on the 2nd floor bathroom, the pipes rattle loudly. This happens ONLY on the 2nd floor's bathroom, nowhere else in the house.

I had a plumber check it out, but we could not replicate the rattling while he was there. He had the hot water running for a long time and checked all other faucets as well, but could not get it to make the noise for some odd reason.
He also checked the pressure outside at a garden faucet and it was 90psi which he said it was too high so he is recommending a pressure reducer to be installed under the house and an expansion tank on the electric water heater at a cost of $600. Too bad he could not hear the rattling and inspect the offending pipe or locate the issue.

The next morning the rattling started again. So, the problem remains.

A little background. The Water heater has never been changed or fixed or never have I had any issues with the plumbing at the house.

My question is whether it is really necessary to install a pressure reducer valve and the expansion tank to solve the rattling created by the hot water on the 2nd floor. Maybe there is another less expensive solution to this problem.

What could be the solution for this localized pipe rattling that just starting recently?

I really appreciate your insight. !!! thanks a lot

 

[voletl]

90 psi is too high so yes I would advise getting a pressure reducing valve.

 

[Mr_David]

I agree! 90 psi is to high. Ideal pressure is 50- 65psi.

 

[cuseplumber]

You probably have a loose washer in the hot side some where

 

[journeyman]

always start with pressure first change out reg

 

[TNguy]

Hello guys!!

I know this thread is old, but the issue is the same and so I thought I resurrect this post instead of a new one.

The issue with the rattling was resolved after I contacted Metro Water (city) and they came and changed the meter outside.

Now almost 2 yrs later the Hot water rattling on the 2nd floor tub came back.

I contacted another plumber and they measured the PSI at the garden hose to be 110. They again (different Plumber) suggested a pressure releasing valve and expansion tank. I understand this since they can't touch the city meter or fiddle with it.

I will be calling Metro water again to see if they can go check it out and fix it (reduce the pressure), but I am curious to know if I can demand they install some pressure valve at the meter or something that fixes the issue for good. I do not live in the property and I am out of state so it is more difficult for me to deal with the issue hands on.

Also, do you think it is fair I have to spend hundreds to add a pressure valve to fix the pressure coming in when it's the city who should regulate this?
And would the Pressure valve be THE fix that fixes the piper rattling if this is just PSI related?

Thanks a lot!

 

[Mr_David]

The City often have systems with higher pressure than you need. They can provide better water service to more users that way. It's up to the property owner to protect their side of the meter. City Is usually not responsible for what happens after the meter.

Those same water mains provide water to fire hydrants as well.
The mains can also fluctuate and installing a PRV on your system can maintain a more stable pressure.

 

[SHEPLMBR]

Ok so you have not resolved the high pressure problem. If this is not addressed you are going to start seeing your fixtures go bad.

 

[TNguy]

So Metro Water came and said pressure was normal? They did not check it apparently since it was at 110psi last saturday and the pipes continue to rattle.
I have a question, why does the high pressure coming into the house make the hot water pipes rattle and ONLY on the second floor shower?

I would imagine a high psi would make more than just the hot water pipes on the second floor rattle. Any ideas?
Also, when they replaced the meter back in 2015 they did not add a PRV or anything to regulate the pressure coming in, it was just the water meter that was replaced and that FIXED the issue and there was no more rattling on the pipes after that. So, I am not sure how just changing the water meter fixed the hot water rattling either.

I'd appreciate if someone can explain these 2 things to me. I am going to have to pay for the PRV valve it seems. Which apparently must be installed with an expansion tank at the water heater too or I risk a rupture? Is this more of a myth or necessity for the expansion tank?

Thanks for any insight

 

[CT-18]

It could be not strapped down well enough. You could also have a washer on the valve starting to go bad and disrupting the flow of water causing vibration. It is sometimes hard to tell without being there. Some of the service guys may know more than me, i am more industrial/commercial.

 

[TNguy]

It could be not strapped down well enough. You could also have a washer on the valve starting to go bad and disrupting the flow of water causing vibration. It is sometimes hard to tell without being there. Some of the service guys may know more than me, i am more industrial/commercial.

Thank you for replying.

I spoke with an engineer at Metro water and he suggested that electric water heater tanks do not "need" an expansion tank when installing a PRV valve. He said gas water heater tanks do, but not electric one.s since the heating process is faster on a gas powered one. He agreed that plumbers recommend expansion tanks sometimes to apiece the warranty on the tanks as required by the manufacturers.

Does this sound correct, it would save me money to only install a PRV. Thoughts?

 

[SHEPLMBR]

Install the PRV. We have been saying that for a while.

 

[frodo]

110 psi for the city water pressure is normal, depending on where you live.
the city has the pressure that high in order to deliver water down the road on top of some hill somewhere.

depending on the municipality, they get water to your meter. PERIOD, you can reduce the pressure if you wish
they do not care. lol..in other words, they do not want the expense or maintance head ache for 1000 prv's
that i te reason it is yours to deal with.
around here it is the same way, what is on this side of the meter is my responsibility,

 

[SHEPLMBR]

Like I said before. It will blow your fixtures if it continues.