Plumbing Noises: Knocking, Whistling, Banging – Sounds In My Home

Everyday almost all of us can relate to the phenomenon of sound.  We know of sounds that provide us with comfort and pleasure.  And we know those that are not all pleasurable and are downright annoying.  Some of these sounds are best described as knocking, rattling, whining or whistling noises.  It is this latter category we wish to explore as so many of our readers have been plagued by the strangest, unnatural sounds creating within their home as a result of unique plumbing related occurrences.  Well perhaps they are not so unnatural, but when you hear them you know you have heard something that is often only unique to homes and the common denominator is often water, pressure, and pipes!

So let us go on a journey and experience some of these sounds from those who know best about them….You!  Our readers have pitched in and we have accumulated a set of the top 50 questions that represent what is going on out there in our homes.  And of course to ease your pain from this most odd and annoying noises, we will provide you with a guide of some of the most popular and effective ways on  how to address these bizarre sounds.

1. When I flush either of my 2 toilets, there is a loud “knocking” sound from outside or the backside of the house.  The sound stops once the bowl refills, and it doesn’t happen when I use any of the faucets, just flushing the toilets.

2. When my toilets stop adding water to the tank hear a loud noise…the noise can also be heard when i shut the water off quickly in the bathroom…the noise seems to be coming from the shower area…

What is going on and how do i fix it?

3. After flushing my upstairs toilet, and water refills the tank, what would cause the pipes to sound like a trumpet.  Very loud and lasts one minute if not two.  I have refrained from using it due to this happening.

4. Our tub keeps backing up with waste from toilet and the toilet in our other bath keeps leaking around floor also the toilet has a gurgling sound with air bubbles

5. Why does my toilet gurgle when I am doing laundry or taking a shower?

6. After I flush my toilet at the moment it stops filling the bowl the pipes in the wall make a foghorn sound that is very loud. I think my condo association had a plumber changed the water pressure in my entire building but I am not sure. How can this be solved?

7. Why do I hear a humming sound after flushing toilet?

8. Pipes behind shower rattle when toilet tank finishes filling

9. After flushing my upstairs toilet, and water refills the tank, what would cause the pipes to sound like a trumpet.  Very loud and lasts one minute if not two.  I have refrained from using it due to this happening.

10. My question is we can hear a faint sound of running water in all of our bathrooms. (can not hear it in other rooms) It is louder in the main bathroom. We have checked all faucets, toilets and hot water tank. Do you have any suggestions on what we should be looking for.

11. When I turn on the faucet in the kitchen or flush the downstairs toilet, the house starts making a humming noise. Difficult to tell where it is coming from but I do not think it is the basement.  The guest toilet upstairs does not make that sound though when it is flushed.  Has been going on for weeks and is starting to get a little louder and last longer. Help!

12. In the house this evening we heard a noise that sounded to me as if someone had started a somewhat muffled motorcycle in the house. My wife and I deployed to find out what was happening. I went upstairs where it sounded loudest over one of the upstairs bathrooms. I flushed the toilet and the noise stopped. When the tank refilled the noise started again. I flushed again and the noise stayed off. Any thoughts?

13. If your shower makes a loud whistle when running whats the problem?Our upstairs toilet makes a loud noise when flushed; what could possibly be causing that?

14. A couple of days ago I was in my half bath downstairs and could hear a sound kind of like gas escaping (we don’t have any gas to the house, only electric). It’s been going on for two days now. The east wall of the bathroom is an exterior wall of the house; on the exterior side of the wall is a spigot that is leaking.

I can hear the sound when I’m standing in the bathroom–it seems to be in the area of the sink, and not the toilet, which is closest to that east wall. I tried turning off the water supply to both the sink and the toilet, and I can still hear the sound–in fact, it’s very similar to the sound an outdoor faucet makes when heard from the inside of the house.

I can also hear the sound from the living room, which shares the south wall with the bathroom. The grout next to the baseboard in the living room, directly behind the toilet, seems to be damp. As the grout in front of the toilet seems the same, I suspect a toilet leak.

My question is this: could the toilet be causing the sound I’m hearing, even though I can still hear it when the water supply to the toilet is turned off? Or could it be the outdoor spigot? The sound is what’s really throwing me off, and since I know that water leaks can be disastrous before they show up sometimes, I’m obviously very concerned.

15. I have a humming or echo sound in my fill lines at home. flush a toilet and you hear it. or the sinks etc.  I did bypass the water softner and drained the water from all faucets then turned the water back on. the sound went away for a while and it’s back ?????

16. I was brushing my teeth this morning and had the water running slowly into the sink in the bathroom.  It is a double sink.  All of a sudden they was a poof sound almost like when there is air in the line but we have not shut off the water to get air in.  The water then turned to a trickle and stoped all together.  I switched to the other sink and the same thing happened.  I tried the shower in the same room and it is working fine.  I tried the sink in the other bathroom on the same floor (second) and it works fine.  I went to the main floor and everything seems to be working except my laundry room sink which did the same thing. I checked the basement and we have no flooding.  Any ideas what is going on.  The house is 15 years old.

17. When noise comes from pipework after you turn off the washing machine what is the cause?

18. You can hear a flush in my upstairs toilet when no one is using it.The water does not move but the sound is there.

19. I just replaced kitchen faucet. when turning water on, hot or cold.  I am hearing a thump or two when the water is running.  Is there air in the line or something else?

20. I put in new kitchen sink and now when I turn on the faucets there is a bumping sound in the water lines. What did I do wrong?

21. I have the sound of running water in my pipes.  When I go to the hot water heater (electric), I hear the same sound.  I turned off the cold water input and the sound goes away.  I checked the meter at the road and the small triangle is not spinning.  When I turn the cold water input to the hot water heater back on, the triangle on the meter begins to spin slowly and the sound returns. I thought it may have been the heating elements trying to constantly heat the water.  I changed both of them out with no positive results.  I still have 2 new thermostats, but did not install them as I saw no point to it currently.  Both thermostats are currently set at 125 degrees. Any suggestions?

22. Hello, I am hearing thumping sounds when we flush the toilet and  the main line coming in makes a thumping sounds and acks like its ready  to blow up.

23. Why does my shower make a loud squeal when i turn on the water.  It doesn’t make the sound when the tub is run, only the shower.

24. We built a new home approx 5 months ago and about 6 weeks ago started to hear a sound when the toilets in either bathroom were flushed. It was NOT every time, but perhaps 40% of time. This morning for the first time it was heard when just using a faucet. The sound is a NOT pipes rattling sound but more of a deeper bellow kind of sound. It lasts perhaps 10 seconds, and again it does NOT happen every time. What might it be ?

25. I hear a banging noise in the domestic water line after the faucet is iin use. What is going on?

26. There is a loud squeal /whine in the pipes after the toilet is flushed. What causes this?

27. When we use the water (turning on tap, showering, flushing, washing machine) there’s a high-pitched squealing/whistling sound.  Any clue what’s going on?

28. Hi, when I drain water front my kitchen sink (ground floor) there is a dripping sound in the wall about 6 feet higher…maybe the main drain from the second floor? Even is you do not turn on the water and just pour say a bucket of water down the drain. What is causing this dripping sound?

29. Thumping sounds from kitchen faucet and it just does not want to go away.  What could be causing this sound?

30. The shower makes a high singing sound when it’s on.  This sound lets up when the pump replenishes the well tank in the basement. The sound does not come from the faucet in the bathtub or from anywhere else.  The water flow doesn’t change when the sound is on or when the pump runs.  The hot and cold remain constant once the shower is turned on.

31. Sometimes when I turn on the Hot Water in my shower, I get a noise and no water comes out.  Then after I turn it off and on again, I get water.  Could I have air in my pipes?

32. Drains seem to flow OK, but get sucking sound from surrounding drains.

33. I have just recently changed my hot water (indirect)storage cylinder. I have a pump installed to the domestic pipework, which is now de-comissioned but my domestic pipe work vibrates whenever I turn on my cold and hot water taps. The vibrations seem to occur when the cistern in the loft is filling up. How can i solve this problem?

34. My toilet sounds like it has running water going into the toilet. You can see water flowing into the toilet. There is no leaks but the running water sound is annoying.

35. Why does my toilet make a loud trombone like noise when flushed ?

36. HELP!!!!, when I take a shower or wash clothes, my water gurgles in the toilet and kitchen sink,later backing up and taking a long time to drain down,and the toilet wont flush out, it just keeps rising…..why and what can I do about it????

37. My hot water tap in the kitchen works correctly on turning on tap. Within a matter of seconds I hear a click from within one of the pipes and the flow of hot waters drops to a very limited flow. I have recently had a pump fitted in the airing cupboard and it is since then the problem has occurred.

38. The house I live in has a basement with a toilet and shower in it. Every 30-45 minutes throughout day and night it sounds like someone turns on a tap and runs it for half a minute and shuts it off…the intervals of this are getting closer. I had to sit in the room off the basement bathroom for 30 minutes until I could pinpoint where the sound was coming from….it was the toilet. It was NOT running like when you have to jiggle the flush handle. I found that when I turned off the valve that supplies the inflow to the tank on toilet and have not had the problem since… problem is what can I do or check so that we do not have to keep the water valve on this toilet turned off. Its a pain to have to turn it on when we want to flush it. The main floor has a bathroom also but we don’t have a problem with it….

39. The toilet sounds like gurgling and comes close to overflowing what could this be?

40. I have a problem with my shower stall faucets.  I have changed the stems, washers and the seats.  The faucets are still leaking.  It appears that the washers wear out quickly and I thought changing the seats would do the trick, it hasn’t. After I completed changing everything, it worked but within 2 weeks it started dripping again.  I pulled out the stems and the washers looked bad again, not worn but indented to the point of needing to be changed again.  I changed the washers but no luck.  Any suggestions would be appreciated.  Thank you!

41.My neighbors kitchen sink has started to gurgle after the water goes out

42. I am considering a tank-less water heater.  I have heard that these units can be “noisy” when working.  Is there any truth to this?

43.The last few weeks I have noticed a low, moaning noise coming from what seems to be our water heater whenever we flush either of the two toilets in our home.  It does not happen when we run water (hot or cold) in any other way…?  What could be the cause of this new noise?  It begins immediately when the toilet flushes and goes away 30 seconds later.  It’s very obvious because our water heater is located on floor level of our house. Please help!

44. When i flush the toilet it sounds like the funnel of a liner. only just started doing this. what is the reason?

45. What is the root cause of have no hot water pressure in the kitchen, bathroom sink and the bathtub? I have excellent water pressure going to he washing machine.I replace the hot water heater,checked with the people who made the hot water heater and the plumbing department at Lowes Department store ok. Is it safe to run a snake real slow down the main hot water line to try and reduce the amount of rush i nthe pipes? I have a hot water heater that knocks on and off to keep the water hot real good. I don’t understand this problem. I also have good water pressure for the cold line in all areas OK.

46.  Can hear the motor from the aeration system, coming thru the sewer lines. The sound is heard worst near the bathtub

47. On our upstairs bathroom faucet, when hot water is turned on, there is a loud pulsating sound in the pipes and no hot water comes on, but you can still get hot water out of the bathtub faucet. This only happens in the upstairs sink faucet and only when we try to retrieve hot water. Thank-you.

48. The kitchen faucet “hammers” when the water is turned on. What can I do to correct this?

49. How do i stop the squealing sound that my shower makes?

50.  At random times, noises coming out of the walls like metal rubbing on metal, then it stops abruptly.  It sounds like something is about to burst.  What do I do and what is causing these awful sounds.

Causes and Solutions to the Plumbing Noises in Our Homes

Annoying as these sounds may be, trust that there is almost always a way in which you can track down the source of the noise and address the cause.  It is important to know that some of the fixes can by done yourself, DIY style.  Follow the the plumbing logic path right to the solution.  Here is a list of some of the best practices and tips you can employ to help with some of these problems.

A. So you are just sitting there watching your favorite program and you hear the knock, knock, knock noise of the pipes in your wall, almost to a rhythmic beat. What on earth is happening? What can be the case is that the pipes are actually knocking against something.  This is caused by pressure differentials, creating this tapping, knocking, or clattering noise.  Pipes could be hitting against board, the wallboard, or themselves. This is sometimes mistakenly called water hammer, not surprisingly because it sounds like someone hammering on the wall.  We will talk more specifically about water hammer later.   Back to the noise you are hearing in the wall.  You need not tear out the wall and begin replacing these noisy pipes.  A more practical solution is to secure the pipes or to wrap them in a foam insulation.    When securing the pipes, you can do so in any number of ways, but leave some room for expansion and some small movement. Sometimes it is just a function of putting something (e.g. rubber, newspaper) in between the pipes in question. Even if they are in hard to get at places, eventually the pipe (or extension of the pipe) emerges through a hole into your home connecting with a fixture.  There is your opportunity to try and silence the noisy culprit.

Now if you turn on a hot water faucet and begin hearing this knocking noise, it may be that your hot water heater is set too high.  Know that when you are dealing with metal, water, heat, and air pressure… can have an orchestra of plumbing noises.  Just turn down the temperature setting for the water heater and see if that helps.

Ok, so what is “water hammer”.  This is the knocking, hammering like noise you may hear if you turn on and off your water very quickly.  It really should not occur if the water pressure levels and air pockets are in proper balance.  Imagine turning the water on very quickly and suddenly stopping it.  Pressure sends the water through the pipe an when your turn off the water, the water suddenly stops and creates it own little shock wave.  Air pockets are in place to act as a cushion to muffle the shock wave.  If the water pressure is too high or the air pockets are too few, you might find yourself hearing these hammering noises.  To remedy this problem, you may have to drain the main water lines for air to enter properly, thereby recalibrating your system.  Too much of anything is often not a good thing….whether it be air, pressure, heat and/or water.

This banging or hammering noise is often heard around dishwashers and washing machines.  As you can imagine, water is being used in large quantities and water valves are opening and shutting to invite water in or stop water in its tracks.  So basically the same principle is in play here.  Water is rushing at many pounds of pressure and suddenly it comes to a screeching halt.  Expect there will be some noise, but if its quite loud and continues on, time to do something about it.  If you don’t have a pressure reducing valve for your home, then have one installed.  Check to see if 3/4 inch pipes are being used throughout your house as the size pipes better allow for water movement.

B.  If wailing, whistling, rattling, moaning or foghorn noises are coming from the toilet area, then check out your ballcock as it may not be operating properly.  This resonance sound can be annoying.  To locate whether its the ballcock, turn off the water supply to all of your toilets.  If the sound goes away, then one by one, turn on each toilet and evaluate which one is the problem.  Replace the ballcock.

Sometimes these noises are due to worn or loose washers in faucets causing the noise due to the fluttering against the water stream.  Tighten as needed. Replace washer if necessary. Or the entire faucet stem assembly may need to be replaced.

If you hear the rapid fire rattling like from a machine gun coming from your dishwasher or clothes washer, it may be due to the selonoid fill valve being in need of replacement.

Be aware that in general, if you have excessively high water pressure (60 psi) you may need to adjust your pressure reducer or install one.  Such higher pressure can put strain on your plumbing system and create a host of noises.  Though, my experience is that people usually have the opposite….low water pressure.

OK….back to toilets.  If you hear the toilet running, stopping, running again.  It is almost always due to the flapper not operating properly.  It could be that the flapper chain got stuck under the flapper and therefore the water at the bottom of the toilet tank is seeping through. This area is called the flush valve. The flapper should create a seal.  Replace as necessary.

If you toilet is making gurgling noises, the problem is probably upstream within your pipes or drain. You may have clogged or partially blocked drain or pipe.  The vent stack could also be obstructed, such as a bird nest or pine needles.  It is likely, one of these is causing the unusual and somewhat continuous gurgling and bubbling noises coming from your toilet.  Removing the blockage is not usually very difficult and you should start first with a plunger, then auger, and work you way up to a plumber snake as necessary.  But before getting into those actions, make sure its not due to the air vent stack being obstructed.

Sounds of the plumbing system can vary and tracking down exactly what and where you are hearing this sound can be a challenge.  But trust, if the sound is repeated, you will eventually identify the area.  From that point, it is a function of doing a little bit of detective work to eliminate probable causes.  At some stage, you will arrive at which solution you should adopt to remedy the problem.

3 Responses to Plumbing Noises: Knocking, Whistling, Banging – Sounds In My Home
  1. Mary Thomas
    August 19, 2012 | 3:40 pm

    Question –

    I have 2 bathrooms. This happens in both bathrooms which are not located near each other.

    When I flush the toilet a loud knocking sound is heard as the tank fills up. What is the cause? How can it be corrected?

  2. Tammie PARKS
    October 19, 2013 | 4:47 pm

    when I turn on the hot water in the bathroom sink, I hear a fast dripping noise under the floor. It stops about a minute after I turn off the water. The cold water doesn’t make a sound. I have had a plumber check it out and didn’t find anything. He said just noisy pipes, but I feel theres a leak. It sounds like one. I have no water in crawl space under pipes but a little sometimes in the basement in the area. only thing is, I would think it would leak all the time, if so, but its only while the water is on a seconds after. Weird, huh?

    • James
      January 26, 2014 | 11:54 am

      @Tammie PARKS no leak its the hot water pipe, when they installed the pipe they drill a hole in your 2×4’s to put the pipe in, they drilled the holes a little to small and the pipe is expanding, and makes a clicking or dripping sound as the heat in the water expands the pipe against the wood hole. Its annoying but if you can live with the noise it not harmful at all.

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