About speedball1 Expertise About me: My Plumbing Expertise: I retired from plumbing after a lifetime in the trade. all phases from service and upkeep to construction, both residential and commercial. I am qualified to do anything in plumbing from fixing a leaky faucet to drafting a set of plans for a commercial shopping center and supervising the construction. My last five years were spent as a trouble shooter for a large plumbing company. I took on all my companys complaints. I have been a expert on the plumbing page at Askme.com. In a field of 200 experts my rating was number one. You may also find me at Answerway.com and AskMe Help Desk.com. This is fun for me and if I can help anybody out that`s iceing on the cake. Degrees & Certifications: As for degrees, I don`t have any. Just a Journeymans ticket, but hey! How about fifty years experience?
Experience Life Experience? Hmmmmmmm! Ran away at 15 and joined a carnival, Navy at 17 Merchant marine at 19 I've had a hellava life.
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In my original question, I mentioned that turning the house water pressure down at the PRV stopped the pipe howl. I've been operating that way for awhile and decided to increase the pressure one turn at a time on the PRV screw to see if I could get better pressure without inducing the howl.
Well, I managed to increase the pressure to a more acceptable level with no howl, but then I made one last half-turn adjustment to increase pressure and the howl came back. Suffice to say, I backed off the pressure to where it had been without the howl.
What's weird about this howl is that when I induce it by opening a faucet and then adjust the flow rate to maximize the noise, the howl will fade out after many seconds and, while fading, the frequency of the howl will decrease to quite a low tone. The frequency range is more than an octave (2:1)change and it changes smoothly. (All this with the faucet in the "max howl" position.)
The mechanism causing this racket to die out in this fashion baffles me! Of course, when I close the faucet and then turn it (or any other) back on, the howl re-occurs and the fading effect can be repeated.
The difference im pressure between settings of the PRV which cause the howl to start or stop are too small to be observed on my 0-200 psi pressure gauge. It's not an expensive unit and it isn't very accurate or sensitive. With the PRV set for no howl, the gauge reads about 38 psi.
Previous Question:
About a month ago my pipes started howling when any faucet or toilet was used. Using either the hot water or cold water faucets caused the howl to occur. The howl seeems to be induced by a certain flow rate.
No changes have been made to the system for at least three years. At that time, a replacement water heater and expansion tank were installed.
I tried turning off all the valves to the various toilets and faucets and then opened just one at a toilet or faucet and ran the water. Then I'd shut off that one and open just one other and try that. In each case I had the howl.
I changed the pressure regulator valve setting, raising and lowering the pressure, but the howl persisted. It would occur at different flow rates with different pressure settings, but it still occurred.
A plumber thought it was the pressure regulator valve because the problem was common to all faucets, etc. The PRV was changed, and the howl was gone for a day, but then it came back as before.
Next, he changed the master shutoff valve for the house. Still had the howl.
One way the howl could be stopped was by closing the inlet valve to the water heater. So a new expansion tank was installed as a test, but we still had the howl.
Next, the heat trap nipples at the top of the water heater in the inlet/outlet ports were changed. (The old ones had the little balls which were known to sometimes cause noise.) The new nipples used a neoprene flapper design that was supposed to be noise free. The howl still persisted.
Well, my plumber didn't have any fresh ideas and I wasn't happy with the cost of all the "fixes" that didn't fix anything.
I called our county water authority (the supplier) and they came out and inspected the meter and said it and the pressure was ok. At this time, they did install a backflow preventer on my side of the meter. This is a project underway for all users. My howl still persisted.
Since all the above changes, I've been able to operate without the howl by keeping the PRV set to a low pressure. It's really not acceptable, but it's better than the howl.
I would appreciate any possible leads to the source of this problem.
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I would have done what you have done. Shut down each fixture and run water. You can eleminate all the fixtures by shutting ALL the fixtures and opening a hose bib at the farthest end of the line. This will not only eliminate the fixtures but the branch lines as well. When you shut down the branch lines the flow will go through the house mains. If it still howls with the fixtures cut out of the loop then your problem is in the main line. If no howls then start to retest the fixtures. In most cases of "howling pipes" I've tracked the culprit back to a faulty ballcock in one of the toilets. Keeep me informed of your progress and what you find out. Cheers, Tom
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You must realize how difficult it is to analyze a problem such as yours without being there. I memtioned the toilets because that's where I tracked most of those calls back to. "Howling pipes" are caused by water rushing past a loose object and vibrating it. Your system picks it up through a process called sympathetic vibration and carries it through out the entire house.. Since you can't cut the tub faucet out of the loop, that's the one I would start with. Shut the house down and open up the cold water side of the tub valve and flush out the supply line and open valve body. Todays code calls for shut offs on all fixtures so they can be repaired without shutting down the entire house. Your problem could be a piece of broken washer or a small pebble vibrating against the seat in the cold water side. One thing is for sure. I would find a way to cut the tub valve, (and any other fixture that doesn't have its own shut offs) out of the system so it could be checked. Untill that's done you can't pinpoint the problem. You're going about it the same way I would. By the process of elimination. You just have to see that you can eliminate each fixture. Good luck, Tom
Answer Good morning Keith, While I can't pinpoint your "howl" I may be able to take the mystery out of the "frequency drop". Your howl is caused by the vibration set up by water rushing by a object caught up somewhere in your system. The frequency of the sound is in direct proportion of the water pressure going past it. Some thing you have done causes the water to flow more slowly. As the vibration slows the frequency will drop in tone. Keith, The only way you're going to find this is to isolate and eliminate each fixture. Now if that doesn't get it I would go about installing a shut off on each branch line and attempt to isolate it that way. The average house pressure runs between 40 and 50 PSI. 38 PSI is only 2 pounds under the average. If running the house at 38 PSI gets rid of the howl why not just leave it at that? I realize this doesnt solve the problem but if it eliminates it, why not? Please keep me in the loop on this and let me know what you come up with. Regards, Tom
