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"moaning plumbing"

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Posted 2011-02-16T18:46:09+0000  by dtkrause dtkrause

Hi j2r2d2!


Yes, that sound is typical of a fill valve that is wearing out.


If you've ever replace a fill valve, you know that the water sound shuts off crisply when new.


I've once saw a historic home with fill valves made of brass ... we don't make them like that anymore!


After 60+ years of service, the master bathroom toilet fill valve began making noise much like yours.


When I took the valve apart, the brass had rubbed so thin that the shut-off mechanism could almost turn off ... but it still allowing a very fine jet of water to pass.


Alas, this fine jet was the source of the whistling pipe!


This particular toilet was so old that replacement parts were unavailable.


However, we were able to "fashion" a new valve pressure point from a piece of brass and replace the worn part.


"Granny" was so happy that we didn't have to remodel her master bath ... and I was too!

Best Answer

Posted 2014-01-23T20:35:00+0000  by Pat_HD_ATL

Hi dtkrause, welcome.  Plumbing systems sure can make a lot of strange noises.  The most frequent sound is a banging sound from the pipes when the water turns off and it's often from toilets.  That's called a water hammer.  When the flow of water stops, the momentum of the water makes the pipe rattle at the end.  To prevent this, a hammer arrestor is usually installed where shutoff valves are located.  It's a stub of capped off pipe that stays full of air.  When the water turns off, the air in the arrestor compresses, absorbing that last push of water and eliminating banging of the pipes.  In time, eventually the space fills with water.  To refill them with air, simply shut off the water where it enters the house and open every faucet in the house to allow all the water in the lines to drain.  Turn the water back on and then turn off all the faucets.  All the arrestors will be filled with air once again.




I don't think that's whats going on.


I really think the issue is with your vent system.  Your sinks, tub, toilets, etc, all drain to your septic tank (or sewer) but nothing would flow through your drain lines if air couldn't get into the drain lines.  That's what your plumbing vents are for.  Without them, it would be like a soda straw when you place your finger over top.  Unlike other plumbing fixtures, toilets place a large volume of water into the drain/waste/vent system at once and place a large immediate demand upon the vent system to supply a large volume of air at once as well.  The air running through those pipes will make some noise and newer systems using pvc (white) or abs (black) plastic pipe are noisier than much older homes with cast iron.  Imagine the vent system acting like a pipe organ.


I would like you to try two things when you get the chance, though and post back.  1st, flush and listen to see if either the sink or tub drain gurgle.  2nd, look at your roof and see if you can identify any sort of plumbing vent.  It could be just s length of pipe sticking up or it might have a cap on it of some sort.  Generally you will see it in the vicinity of a bathroom and there will be 2 close by, one being a vent fan vent and the other being a plumbing vent.  I'm just trying to determine the likelyhood of a clog.  That could affect the pitch/audibility of the sound.


Good luck

Posted 2011-02-16T22:02:19+0000  by brianstile

Welcome dtkrause and brianstile!! 


I'm afraid I really don't have anything to add to Brian's post, you hit the nail on the head brianstile! It sounds like a vent pipe clog to me, oh joy what a great excuse to climb up on the roof (we all love those)....... :smileyvery-happy:


I hope to see both of you around the forums, happy home improving!



Posted 2011-02-17T00:00:55+0000  by BlakeTheDiyGuy

Found this thread doing a search for "moaning pipes"!  Great info here.  I'm having the same problem described by the original poster (and coincidentally, my house is also about 6 years old), but with some unique twists:  1) I hear the moaning shortly after running ANY water (i.e. not just flushing a toilet) - brushing my teeth, washing my hands, etc.  Shortly after, I'll hear the noise briefly - always sounds like it's coming from the same location regardless of where I ran the water.  2) In one bathroom (out of three), when I run water in the sink, it sounds like it's draining in/from the toilet.  


Does this still sound likely to be clogged vent pipe?  (BTW, I'm on city sewer system, not septic.)


Now the second question:  let's say it IS a clogged vent pipe - how does one confirm that, and how does one CLEAR a clogged vent pipe?  (And how does a vent pipe GET clogged?  I have no trees anywhere near my roof, so it wouldn't be leaves/debris/etc)


OK, I guess that was more than just a "second" question.  Thanks for any further insight/input/advice.  

Posted 2011-09-14T18:39:37+0000  by gatodelsol

Hi gatodelsol, and welcome to our community. I’m glad that you found this thread, and I think you definitely have a problem in a vent stack. I have attached a picture below of a sample DWV system (Drain, Waste and Vent).


Vent Stack.JPG


You can see that the yellow pipes are vent pipes, they admit air into the system to promote smooth and efficient draining, The green pipes are drain lines which get the waste water out of the house. Where problems often arise is where branch drains meet the main vent stack (circled in red). Imagine that as waste water comes from multiple sources (vanity, toilet, bathtub ect…) it hits this tee and goes down as a result of gravity. But not 100% of the waste will end up going down. In moments of high demand some waste may momentarily find its way into the vent pipe, that waste over time can dry up and cause a blockage that will cause slow draining and gurgling as air is sucked through a smaller and smaller orifice (just like if you tried to empty a two liter bottle by tipping it completely upside down, you hear a ‘glug glug glug’ as air is admitted into the bottle).


The solution in this case is to clear the vent pipe! This will require a trip to the roof, and it is at this point that you might want to consider hiring a professional to do the job. A professional drain cleaner will be comfortable working on your roof with machinery, he will have the proper safety equipment, and appropriate insurance to protect himself and your home in the case of an accident. However, if you want to try to clear the drain yourself I’ve got a few simple tips that might make the job easy for you.


Anytime you are working on your roof be sure you are using approved fall protection gear, along with any other protective equipment you may need. 

Fall Protection Kit.jpg


The first step is the old hose trick. After you locate your vent pipe and secure your safety harness, take a regular garden hose with a pressure nozzle and push it down into the vent pipe, if you reach a blockage have a partner turn that bad boy on full blast and see if you can’t spray the gunk right down the line.

Hose Pressure Nozzle.jpg


If the hose trick is unsuccessful, you will need to snake the line. At this point you may want to cut your losses and call out a professional. Using a power snake is tricky enough on level ground. Also many professionals will guarantee their work, in case the problem comes back.


I wish you luck gatodelsol! Please don’t hesitate to ask if you have any additional questions.



Posted 2011-09-20T22:52:07+0000  by BlakeTheDiyGuy

I have an added symptom:


I have a 6 year old house on septic.  In the master bath, if I flush a toilet, turn on a sink, or even if water leaks from the bottom of a closed bathtub I hear an aweful groaning and vibrating sound.  However, the sound usually goes away after the first 20 seconds even if the water is still running.


Before I climb on my roof, does this still sound like a vent? 


Thank you,





Posted 2011-10-17T21:02:26+0000  by janderson

I read this post and also have a problem with noise in my toilet vent pipe as well as bubbling noise in the toilet when I run the washing machine. We have  lived here 9 years and never had a problem with any plumbing at all. Then 2 years ago we added on additions to the house including 1 1/2 bath. Thats when we started hearing the noises. When you flush the toilet we hear a rumble in the vent pipe not all the pipes just the main toilet we started with. We have snaked the toilet pipe to the septic, snaked the vent pipe and nothing is blocking it. We also developed the bubbling in all of the toilets when I do laundry. Again we have checked all the drains, pipes , vents for clogs and found nothing. We did have a professional plumber install all the plumbing, so it is not a do it yourself job. We also now have a problem with the septic when it rains alot filling up and unable to flush any water until the rain stops. Do you have any ideas what could be causing the various problems I have described?

Posted 2013-01-28T16:53:54+0000  by gpdp7519

Hi Brianstile,

I have a post with plumbing that is making noises and I wonder if the vent could be the issue as it might be in this case.

If I go up to the roof and find the vent associated with the bathroom in question - how will I know if it has a problem ?  If there is a clog for instance - would I run a snake down it or how would I diagnose the issue and then resolve it ?

Any help would be appreciated - and if you have a moment to read my post on my specific issue I'd love to hear your thoughts.

Posted 2013-07-23T22:45:00+0000  by gachan

Not sure if I have posted in the right place. But.


I get plumbing moaning if I have the washing machine or the shower or the dish washer on and then flush the

toilet or use one of the other supplies. It's like I cant have two things using the same supply with out moaning.


We recently had a tree root blockage in the pipe that leads to the council end of the pipe. that has been cleaned out 

and about a month after that we started getting the moaning.


I dont have a vent pipe running up to the roof, I have one on the ground where when we had the blockage we sore

toilet paper coming out of this but that has been cleared.


I am at a loss and it is starting to get annoying.


Any help would be good



Posted 2013-08-23T10:22:59+0000  by Fungirl

I read previous items. My issue is a whining/moaning that only occurs when one specific toilet is flushed and it doesn't happen until the toilet tank has completely refilled and the water has stopped running, so it doesn't sound like vent issue. Any ideas?

Posted 2014-01-21T19:13:12+0000  by j2r2d2
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