Photograph of a multi-S-trap plumbing fiasco Plumbing Drain Noise FAQs #3
More Q&A on solving plumbing drain noises

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Plumbing drain noise diagnostic FAQs: set #3.

Frequently-asked questions & answers about the types, causes, & remedies for plumbing drain noises & sounds.

This article series explains how to determine the causes of plumbing drain noises, and we refer to key companion articles that assist in that diagnosis, and we include plumbing noise cures.

We also provide a MASTER INDEX to this topic, or you can try the page top or bottom SEARCH BOX as a quick way to find information you need.

How to Diagnose Sounds of Gurgling or Other Noises in a Building Drain Piping System

Dishwasher drain hookup to sink trap tailpiece (C) Daniel Friedman Reader Questions & Answers about Plumbing Drain Sounds posted at the end of PLUMBING DRAIN NOISE DIAGNOSIS - be sure to review that article.


On 2017-07-15 13:11:20.511741 by (mod) - drain clogs are more-common than vent clogs


Drain plugs are in my view much more common than vent clogs (unless it's a wet vent that also handles drainage). That's because of vent pipe in most Plumbing Systems is normally open and filled just with air while drains have Solid Waste flowing through them and are more prone to blockage.

So on my view I always start by attempting to clear a clogged drain. If plunging a toilet or a sink or a tub or shower drain doesn't clear it after a few minutes of trying I might then need to actually have the drain snaked or cleared with a power auger. If you use the inspectapedia search box above to find out article on kinetic water Ram you may find another neat tool that can often clear a blocked drain

On 2017-07-15 by Nathan

I've been living in this upstairs apartment for about 3 months now and just this week the bathroom drain has been glug gluging. It started real quiet and has been getting progressively louder. I now have to close the bathroom door and can still hear it

. I've done some research and people say it's probably the vent pipe or drain pipe clog/partial. My question is. How do I find out what one it is? Drain or vent? I'm on the second floor and it's technically a condo so no on site maintenance. Please help.

On 2017-05-16 by (mod) - Pumping the septic tank will never fix a clogged drain nor a failed draonfield.

Pumping the septic tank, while required to preserve the drain field, will never fix a clogged drain nor a failed draonfield. A septic tank, in nomal use, is always full..

What we don't know is if the clog is between your house and tank or rather if the draonfield is failing.

Motor noise that you hear sounds like a sewage ejector pump

On 2017-05-16 by Kristy

Live in Florida, been in home 13 years, have septic tank with sump pump tank and no filter between the two, never had to pump tank out until today. Kitchen sink has its own pipe to the main pipe running to the solids tank. Started to back up after few seconds of running water.

Snaked it 3 times, draino it twice. Thought it was just septic need pumping. Note V both full bathrooms drain fine. Started hearing what sounds like a motor, possibly the sump pump, running in the sink drain after the water would go down.

After septic was pumped today the sink was still clogged? Snaked it again and water appears to be draining only we hear this motor type sound coming up from the drain and is rather loud? NEVER heard this sound before after 13 years? What is it?? Husband says its the sump pump, so why have we never heard it before?

There's no baffle down low in the tank only at the top going to sump pump section. I disagree with him only because I know I have not run 1000 gallons of water in a few hours to fill tank and cause pump to kick on. What in the world could this be??? Please help so I don't feel like I'm starting to just hear things that were never there before? Lol

On 2017-05-06 by (mod) - why does kitchen sink noise change?


If the noise is coming from the plumbing drain, I suspect that we're seeing a difference in the rate of flow of water into the drain. If the noise is coming from the supply piping I suspect that when you move your sprayer you are thinking a flexible line under the sink and reducing the water flow rate.

On 2017-05-04 by babygirl

why does the kitchen sink make a diffrent nosie when i spray the spout in a diffrent spot

On 2017-04-24 by (mod) re: kitchen sink bubbles my toilet bubbles when my shower is on


It sounds as if the vent for the drain system you describe is clogged or incomplete, but it also sounds as if the main drain or toilet drain is clogged. If plunging for a while with a toilet plunger doesn't fix the problem start


On 2017-04-24 by D

My kitchen sink bubbles my toilet bubbles when my shower is on and shower is clog up and water is staying in it toilet running overs please help me

On 2017-04-23 by (mod) re: After a hard rain dishwasher flooded

TR Yes what you suggest is possible - moreso if your home is connected to a private septic system.

On 2017-04-23 TRowe

Recently I had 2 odd things happen. After a hard rain I used my dishwasher as usual and it flooded. Thinking it was a fluke I got the water up after inspecting the dishwasher. I washed clothes all day and at the end of the day once again ran another load in the dishwasher while also washing a load of clothes.

The next thing I know the house is flooded. I think this was probably caused by a slow drain from the recent rain. Is that possible?

On 2017-04-19 by (mod) re: washer and its drainpipe, smell like sewer.

I suspect the drain is not vented,and it may also not be a proper destination for the washer drain.

On 2017-04-19 by Libby

My washer and its drainpipe, smell like sewer. The floor drain 5 ft from the washer waste line gurgles or makes sucking noise. Dehumidifier, AC and air exchanger have hoses draining into the this floor drain. Put water into floor drain, still makes noise.

On 2017-04-03 by (mod) re: low running noise in a home

I don't know, from just y our e-text, anon, what is causing a "low running noise" in your home. If you mean running water, I'd start by shutting off each plumbing fixture individually - that can diagnose the source, such as a running toilet.

On 2017-04-03 by Anonymous

We had new pipes installed in our home recently and now have a low running noise that I don't know where it is coming from. Could it be the new pipes?

On 2017-03-27 23:07:12.476657 by (mod) re: signs of a clogged drain or blocked vent show up at the kitchen sink when washing machine runs


Usually the problem is either a clogged drain or a defective or blocked vent. It sounds to me as if the kitchen sink drain comes down to a point where the washer drain joins it and then continues out of the building - if so I suspect that the vent is inadequate, missing, or clogged; the added drain volume of the washer flowing through the drain system creates a vacuum that is burbling back up through the sink because it's air -starved.

Most washers empty into a standpipe that acts as an indoor Vent. It's possible that your washer drain hose is tightly fit or even sealed into its standpipe, exacerbating the drain problem.

You may need added venting on the washer drain.

On 2017-03-27 by Carolyn

Help please my kitchen sink above the laundry room gurgle each time the washing machine empty! It is only the sink in the kitchen and not to the bathroom next to the laundry room It drains fine so the noise is only in the kitchen drain !!!

Been in the house 40 years and this problem is 2years old . I had a clog in 2015 and 2016 Plummer said it was from the wrong t paper so I switched!' And now that noise is back but drains run fine
Any thoughts that you can help me with
Oh yeah my second floor bathroom is fine also!! Just the noise in the kitchen from the washing machine

On 2017-03-18 by (mod) re: signs of inadequate venting of a sink or lav

Alex it sounds to me as if the way the sink drains are arranged one of them is inadequately vented. I speculate that using the sink that is more-remote from the actual drain line is when you hear the problem.

But it could go either way. If the sink pair is inadequately vented, water passing down one of the drains may be creating enough vacuum to draw air in through the sister sink trap.

On 2017-03-17 by Alex

I wanted to clarify my previous comment I have two sinks next to each other both drain perfectly when you run one and not the other there's a bubbling noise coming out of the other drain. When I run the water in the other one that noise goes away.

And if you run the one that has the bubbling noise and not the other one there is no bubbling in that other sink.

We have two bathroom sinks next to each other. Both work fine but when one of them is Only and not the other always same one) , there is a bubbling noise in the drain of the other sink not being used.

If you run water in the other sink at the same time the bubbling noise goes away. and it IS NOT the same the other way around. Why is that both drains drain perfectly,

On 2017-02-22 by (mod) re: signs of a blocked or clogged soakaway bed or leach field

A failed or blocked septic drainfield

On 2017-02-21 by Mary

A vent pipe, located in the drain field occasionally has water pouring from it. What can cause this?

On 2017-02-14 by (mod) re: water pools in the shower and in the yard


Unlike Johnny Carson's Magician the Great Carno, I can't really see what's going on at your home, what plumbing system piping, drains, routing, vents, leaks or blockages are occurring as your message is (nicely) brief.

But I am GUESSING that your main drain is blocked (or if you're on septic, the tank or drainfield are blocked or in failure).

That might indeed cause drainage to back up to a level at which it empties at a vent opening the the drain system that is sometimes found on some buildings in a building wall or at an inspection port along the run of a sewer or septic line.

Time to call a plumber.

On 2017-02-14 by Vee

Water pours out of the drain on the side of our house when we use the shower.

For the first time today, the water actually pooled on top of drain after all shower water ran down the yard.

Why would the water come up out of drain and down the yard ?

On 2017-02-15 by (mod) re: mobile home drain noise diagnosis and repair


Sounds to me as if either a drain remains clogged or a septic system is blocked or has failed. Sometimes in cold weather a drain may be blocked or partly-blocked by freezing-up. A plumber with a sewer line camera can usually find the trouble spot.

On 2017-02-13 by Megan

Recently we been having problems with our drains, we leave in a mobile home park,

I first noticed it when the toilet would flush the kitchen sink would gurgle, I informed our landlord about it and the maitence guy came and check things out, but of course it wasn't making any noises, he replaced the air vent thing to the kitchen sink drain, and it didn't do it again for a couple days, then started back up

, first the kitchen sink would gurgle, then later when my son took a bath and use the toilet shortly after and when he flushed it overflowed, and we noticed the tub didn't drain, plunging didn't help any, and it randomly drained by its self,

not sure what could be causing this problem, since it has drained its self the toilet keeps gurgling, and we ran the tub to see if it would drain and it did but then the toilet started gurgling again.
Also have high windy weather

On 2017-02-03 by Sherri

I have an older single wide mobile home and as I sit here I can hear water going through my pipes like it's pouring but I don't have any water turned on nor have I all day long. Why is this

On 2017-01-15 by (mod) re: plumbing noises from the toilet sound like it is self-flushing

Even changing a toilet flapper valve does not necessarily guarantee that you have fixed a slow, subtle leak out of the tank into the toilet bowl - that will ultimately lead to a minor self-flush. That's because the seal of the flapper to the valve base may still be poor unless the entire assembly is replaced. You're just replacing the flapper itself, not the seat to which it must seal.

Two things to try: dark food coloring (or septic dye) in the toilet tank may show up a leak in colour after a time. Or buy a new toilet fill valve from Fluidmaster - the model that includes a new feature: the valve will not drop and re-fill the tank if the tank is leaking. It only re-fills the tank in response to movement of the flush lever.

With that valve in place, if the tank is leaking it will indeed slowly leak out, but when you next check the toilet you'll find the tank low or empty.

Look for the Fluidmaster 400LSR Universal Fill Valve with Leak Guard.

InspectAPedia is an independent publisher of building, environmental, and forensic inspection, diagnosis, and repair information provided free to the public - we have no business nor financial connection with any manufacturer or service provider discussed at our website.

On 2017-01-15 by Help please !

House is 8 yrs old. On septic. We have two bathrooms. The one adjoining our bedroom (used the least) which is at the end of the house occasionally sounds like it tries to do a minor flush. I was thinking possible ball cock assembly or flapper

. The flapper has been changed a few times. Not the assembly. Nor has the septic been emptied as just my husband and I. What's weird is that sometimes...days on end.... when ever water is run at any point in the house even if that particular drain where the water is run is "closed off" at the time, when the water is turned off, it sounds in this one toilet like water is sloshing against the side.

I am so at a loss and quite worried as the inspector told our Government builders that if they ever used that Plummer again, he'd never inspect another of their houses.

Though he let ours through. Ohhh the troubles we've had. Shiver, shiver. I mean Who puts overhead plumbing in the walls and then runs outer wall insulation beneath the pipes instead of outside of them. That give you an idea of why I'm soooo worried ?

Though I will try to find your site again, is there anyway please that you could copy your answer to my email ??? PLEASE !! Thank you. Am disabled so monies are snug. Maybe a pro can help us pinpoint the issue and still keep an arm if not a leg. Thanks again. :). Steff

Older Plumbing Drain Noise Q&A

On 2013-01-11 by E Wayne Rouse

I had the septic tank pumped recently. Now, when the outside air compressor comes on, I get a loud continuous thump from one sink in the bathroom. No other sinks make a noise. Occasionally, the toilet backs up, but it is not making any noise, and is flushing normally now. The thumping will cause the stopper to vibrate. Do you have any idea what I should do, or why it just started?

On 2013-01-09 by Help!:) - Every 2 seconds, "donk"

We are in a new home, so a new septic tank system. Been here two years now. It's a pump system into a mound it's been very very rainy, fromVanvouver. Anyway the tank outside is making a banging noise.

Every 2 seconds, "donk" loud enough that we heard it inside. The alarm on the pump has not gone off yet this banging noise can not be good. It's almost like a pump is going off with nothing inside. ... Like its lacking water.

On 2013-01-05 by Ellen

When it rains and when tub drains I then hear in the other bathroom the toilet seems to flush or water running in pipes. Or on its own the sound happens in the middle of the night What causes this?

On 2012-12-29 by Susan

We live in an apartment and can hear a glug glug glug noise in the wall between our apartment and the neighbor next door to us. We share a wall. Her bathroom is in the area we are hearing the noise.

Her unit and our unit are a bit staggered, so our bathrooms are not in the same places. Our kitchen wall is on the other side of her bathroom. So we are hearing this sound come and go constantly.

We will be sitting in our apartment and hear this glug glug glug noise for about 1-2 minutes and by the time we figure out exactly where it's coming from it stops. Then an hour later it's doing it again.

The noise is getting louder and louder. Any idea what this could be? I'm inclined to think it's an issue with her drain. Thankfully we don't share drains. our units have separate main drains that meat up in the back yard behind the building. (I know since I used to be an onsite manager).

On 2012-11-25 by (mod) -


Sewer gases may come up from the sink drain and the drain may be noisy because you have no working plumbing vent

On 2012-11-24 2 by trevor

my sink makes farting noises, what is it? why is it doing this? and it smells like fart gas HELP!

On 2012-11-23 by (mod) -


Often when we encounter the situation you describe the problem is a blocked or otherwise defective plumbing vent. If sufficient air cannot enter the drain line through the vent stack to satisfy the negative pressure in the drain as a surge of water flows through it, the suction created draws air into the drain through nearby traps, causing the sound you describe.

On 2012-11-22 by Jasen

also.... on that last question I noticed that my voice recognition on my phone is translating "and the" 2 in the :)

On 2012-11-22 1 by gurgle and draining sound coming

so here's my question, anytime I flush my master bath toilet I hear the flushing/gurgle coming from my jacuzzi overflow. when I run water down the drain of 1 of my master sinks I hear the water draining in the tub overflow.

when other toilets on the second and first floors are flushed I also sometimes hear it in the overflow. I don't think that I have ever heard it when I use the other sink in my master bath.

I do not seem to have any slow drains in the house. there appear to be at least four vent stacks on my roof 1 of which is a large.

Home is about 4500 square feet 2 floors in the basement with 2 bathrooms on the second floor in the laundry room 1 powder room on the first floor and the kitchen and 1 bathroom in the basement. interestingly enough it looks like the kitchen sink in the bathroom sink in the basement both have those cheater valves attached. home is only about 16 years old

On 2012-11-03 04:27:42.455876 by Richard A

I have a basement floor drain near washer that started to gurgle and bubble when clothes washer drains water. I noticed water level in drain was low which was not the case before. I can fill water in it and it does not overflow so I assume no blockage and I snaked it a couple months back.

Now the gurgle stopped after I filled drain whole back full of water. The drain for washer and drain in floor are same smaller diamater so I think they are connected before the main sewer drain.

No toilets or sinks gurgle and drain seems to only gurgle when laundry was done. Now that it stopped gurgling was this just because water level was lower than pipe at bend and allowed air to push through?

On 2012-10-17 00:16:24.879838 by (mod) -

If the basement drain never gave those problems before i suspect that either it was blocked or not connected to the main drain that was recently repaired, or during repair we lost a connection to a plumbing vent, or previously the floor drain was indeed drawing air in when the main drain was in use but was dry )no gurgling), or, another possibility is that your repair has lest a partial drain blockage downstream.

See if youncan have the drain system checked by camera.

On 2012-10-17 by (mod) - look for a shared drain or vent line

Debbie, look for evidence that your flat shares a drain or vent with another

On 2012-10-16 by Tim

We just had exterior plumbing work done on the sewer line between the house and the city main. Our basement floor drain is now wicking/siphoning/emptying and the smell of the CIPPs liner and sewer is coming into the house. I have done a brief check for causes of the emptying, but if you have any suggestions... thanks in advance

On 2012-09-29 by Debbie C

I also meant to point out I have only owned this property for 2 months, and the noise has become considerably more evident over this period so I assume it was there before. It was previously a rental property, so nobody had mentioned these issues to me at time of purchase.

Thanks for your message. The bath is gurgling without any taps run/toilet flusing etc in my property a lot more regularly now, so I'm not sure what to try in terms of checking for clogs?

Would you recommend either high strength cleaning agent down the plugholes, or snaking the bath drain perhaps?
If its any help, I have been informed that the bath drain is actually lower than the toile waste drain, so I don't know if that may be something to do with the noise? Just keen to make it stop now! :(

On 2012-09-28 by (mod) -

It sounds as if you may be describing a partly blocked drain or vent. Ask your plumber to check those.

On 2012-09-28 0 by (mod) -


the plumber had a good suggestion. To diagnose further, consider that as the noise is new we shouldnaskmwhat may have changed. A clog, for example wouldnbe a change. If the problem were due to originalndesign or installation the symptoms ought to have been present since the time of construction.

On 2012-09-21 by Debbie C, UK

I live on the 3rd floor of an apartment building in the UK. Whenever I use a toilet cleaning product, and flush away, the bubbles in the toilet bowl seems to cause the bath drain to gurgle loudly.

I spoke with a plumber who advised if it only occurs in this instance it is likely down to an anti-vac valve having been fitted, so left it at that. This morning however, the bath made the same noise although the toilet in my property was not flushed, so I can only assume was caused by a neighbour or flat above/below flushing their toilet

I then flushed mine twice (with no waste or cleaning products in) just to see if the flushing action caused the noise again, which it did - 3 times - so I am now concerned that this is maybe a fault with stack vent pipe or something in the building itself, rather than limited to my property.
Any help will be greatly appreciated.

On 2012-09-21 by Sharon

We live in a 20 yr old 2-story colonial with walk-out basement. Recently, our upstairs bathroom sink began emitting a stinky odor from the sink. I used drain cleaner several times but the smell remains.

A bit more recently, we began hearing a glub-glub sound in the powder room pipes when running the water in our kitchen (which is next to powder room). We only hear the sound when the water is run longer than 20 seconds or so.

Are the two connected? What needs to de done?

On 2012-09-16 by (mod) - unsuccessful effort to clear blocked drain

Joe B

It sounds as if you are not actually reaching and clearing the drain blockage. For example if a sewer line is partly collapsed, the partial obstruction can cause solids to back up at that point; plunging or using other means such as a pneumatic drain blockage clearing tool can push the waste past the pipe damage but that point quickly clogs up again.

An experienced drain cleaner using a rotating snake can sometimes feel an obstruction or break in the sewer line, or s/he may pull out tree roots - both indications that excavation and line repair are needed. Or you could get lucky and clear a blockage that stays clear for a time.

On 2012-09-16 by joe b

i have 3 bathrooms two on the top floor one in the basement the one in the basement overflows when i plunge in it eventually goes down but then again fills up and very slowly drains also i hear gurgling sounds bubking sounds could my main drain need to be cleaned out or is it poor ventalation there is no smell

On 2012-09-06 2 by (mod) -


to unclog a pipe yourself, presuming we're talking about a drain pipe, follow instructions that start at

CLOGGED DRAIN DIAGNOSIS & REPAIR (links found at the INDEX to RELATED ARTICLES near the end of this page) - try a toilet plunger first.

On 2012-09-06 by (mod) - I can hear noises in the bathroom


It sounds pretty baffling, I agree; If close under the floor tile in the bath you describe there is a heating pipe or hot water pipe through which hot water has been flowing that could explain the warm tiles - or do you have radiant heat flooring?

But FIRST, check for a leak in the hot water piping in the area you desctibe - inspect that bath floor from below, looking for signs of a leak in a hot water pipe.

I'm not clear on a likely link between plumbing noises elsewhere in the house and warm bathroom floor tiles.

On 2012-09-05 by sandra

I can hear noises in the bathroom as if the water is on somewhere else in the house. At the same time, the tile feels hot to the touch in the same bathroom.

On 2012-08-17 by Heather

How do I unclog a pipe myself?

On 2012-06-20 by (mod) -

Rick, I'd try using a mechanics' stethoscope or a similar device (Radio Shack) to see if you can zero in on (and photograph for us) just what you find. It could be a loose pipe mount., I wouldn't expect thermal movement alone, in a drain line, to explain this tapping sound.

Also, is there a check valve anywhere in the drain system? Could that be making the noise?

On 2012-06-20 0 by More on the "tapping" sound

Dan, Thanks for the reply. I tend to lean toward the latter, only because of the sound it makes. Sometimes (but not always), it will occur after the first person takes a shower in the morning.

That didn't happen today, but it did happen after my wife did a load of laundry. The sound is very rapid (about 5 per second), and above the master bathroom it literally sounds like someone is shaking the pipe back and forth.

On 2012-06-18 by (mod) - tapping noise in drains


a "tapping noise" coming from a drain line is often a drip - water droplets fall down a vertical section of vent or drain piping until they hit a bend or elbow where they can make a smack or tap noise.

See if you can track the tapping noise to use of certain plumbing fixtures - for example, a long hot shower taken in cold weather may lead to condensation inside the vent pipe as it passes through a cool attic. Also check for dripping faucets and running toilets that send a slow leak down a drain line.

Another source of "tapping" sounds we find in both supply and drain piping can be due to thermal movement of the pipes as temperatures change. Sound isolating fittings or more clearance at openings for pipes can cure that trouble.

On 2012-06-15 by Rick Bolan

I have an intermittent "tapping" sound that I can hear in the ceiling of my main bathroom, which can be heard very clearly in the drains of the kitchen sink

. The area of the ceiling is where a large drain vent pipe is located, and the kitchen sink is on the other end of the house. It seems to come back every week or so, and it continues on and off for maybe a 1/2 hour.

Initially I thought we had an animal in the attic, but there are no signs of that, and the sound is too "rythmic" to be an animal. It happens at no particular time of day, and doesn't seem to correlate with any large water use. Furthermore, all the drains in the house seem to work perfectly, especially the kitchen sin

k. I'd call a plumber in, but I can't predict or control when it's going to occur.

Any ideaa? It sounds almost like someone's upstairs shaking the vent pipe back and forth.

On 2012-06-14 19:29:44.363408 by (mod) -

Wendy, thanks for the question, but I just don't know what a steaming noise sounds like - do you mean hissing? Steam, produced by boiling water, is not itself a sound. As you hear the noise at drains, its a plumbing question not a furnace question.

On 2012-06-14 by wendy - steaming nooise at drains

my drains are making a steaming noise (best way i can describe it) i hearing it in all the drains (sinks, shower,etc) in the basement it sounds like it coming from a part of the furnace the humidifier...any suggestions as to whats wrong??? who do i call a plumber or some one for the furnace???

On 2012-05-31 by (mod) -

Trish: loud humming is not a sound I've found traced to drain piping, but the fact that you hear it increase when a fixture is used suggests to me, with so little information, that perhaps there is a pump involved in your drain or sewer piping? If so check for pump noise being transmitted through piping. The fact that you hear the humming when drains are not being used argues in the opposite direction, but if it's from a drain pump it may not be activated until a reservoir is filled to an action level.

In sum, accurate tracing of the sound to its source may be aided by more recording of times of occurrence, and observation of what other equipment may be operating at that time, or even wind, insect, or animal activity.

On 2012-05-31 by (mod) - air conditioner drain noises

Frank, regarding air conditioner drainage and pumping and drain noises: an A/C condensate line usually has a trap right at the cooling unit, then slopes continuously to its drain point - in your case a sump. If you can trace the sound to that drain system I'd look for a partial blockage in the drain piping.

I'm unclear on what you mean by water heater drain pans - perhaps you mean a pan under a water heater intended to catch a leak and prevent floor damage? That pan is piped to a drain? If that drain is a building drain and it's gurgling it suggests a partial blockage further into the main building drain piping system.

On 2012-05-31 by Trish

having problems with Loud humming noise in house located in bathroom - happens at night when the sink has not been used or the toilet has been flushed can hear this all though the house for hours on end. and gets worse if any fixture is used.

Plumbing is all new installed 3 years ago. Plumbers say no toilet leak and no leaks in the system and it is working as it should. had all vents spray jetted and flushed out and still had the noice that evening - City has ben out and replaced thier meter and still noise.

Sewer contractor after scoping entire sewer line that it is old and should be replaced but would not cause this noise...I am at my whits end and am getting no concrete answers as to how to fix this...but have spent a lot of money and gotten no where....any ideas

On 2012-05-30 by Frank

I live in a 7 story condo. Last year the association installed a outside sump to curtail flooding that was supposedly caused by the air condition drainage.

The sump, as explained to me was connected to only three unit stacks, e.g. units C, D, & E. In the last two to three months several neighbors have noticed a sort of knocking, gurgling sound coming from the line that serves the drain pan for the water heater, which I assume is also connected behind walls to the line that the air condition drainage for all units.

Maintenance people and on site manager say it isn't the sump! If water is poured into the drip line it does evacuate with no problems. What do you think? Sounds like something sucking air.

On 2012-05-29 by (mod) - water supply pipe noise may suddenly appear, in the form of running water,


A water supply pipe noise may suddenly appear, in the form of running water, might be traced to a lost or loose pipe support, insulation that has been removed or become wet (conducting more sound), or noticing a noise that actually was present before. Often when we first notice something we are sure it's new when in fact it may not be in some cases.

If the noise is in drain piping, your system may have developed a partial drain or vent blockage, leading to a new gurgling sound that was not there before.

On 2012-05-29 by (mod) -

Liam, check for a partially blocked drain or vent pipe.

On 2012-05-20 by deene

recently I'm hearing a noise in my walls whenever water is running upstairs and I'm downstairs. It can be a toilet flushing, the shower running or the washer running. I've never been able to hear it before and there haven't been any plumbing changes. What might be causing it?

On 2012-04-20 by (mod) -


I don't have a clear understanding of your question: a self-flushing toilet? The only versions of that I've seen use an IR sensor and are in public restrooms. I suspect you have a bad flush valve.

If you mean you hear flushing water through the drain pipes but no water is being run in that bathroom, then clearly you've got water coming from somewhere else - perhaps a higher bathroom or nearby plumbing fixture? With so little information I can't diagnose it.

On 2012-04-18 2 by Anonymous

My downstairs bathroom will flush every 5 minutes without using the toilet. Flushing sound is coming from the piping. The home is over 60 years old with copper piping. What is causing this noise?

On 2012-04-17 0 by (mod) - gurgling noise that comes from all of my drains

Chris gurgling drains can mean a blocked vent or a partial drain blockage - as you've been exploring. The duration of the gurgling sound, if it's a blockage or a vent problem, varies by the amount of wastewater being sent down the drain. The toilet doesn't gurgle because it's in a sense self-venting - it draws air into the toilet bowl and drain during the flush cycle.

You can add a vacuum breaker "anti-siphon" device as a diagnostic - that will help only if the problem is inadequate venting or a blocked vent.

On 2012-04-13 2 by Chris R. Stevens

I have a gurgling noise that comes from all of my drains except the toilet. I have tried to auger all of the drains to no avail. The gurgling is loud and only lasted about 30 seconds. Now it is slower and last about 2 minutes or longer.

Th e house was built in the 30's and has only one bathroom on the main floor and a sink and drain in the basement. I have been told that I should add an anti siphon trap as a remedy. If that is the problem where is it installed?

On 2012-04-07 by (mod) - hissing at a tub drain

Ted, hissing at a tub drain is not a sound I've come across, but I still suspect it might be a combination of a partial clog and an incomplete plumbing vent system - it sounds a bit fantastic but if a lower drain has water running through it and needs to pull air into the DWV system, and if that air is blocked from the vent piping, air might get sucked into the drain from any other plumbing fixture.

We can get past this arm-waving speculation with a test: try filling the un-used tub drain with water - just to fill the trap. Then run water or flush toilets in baths on the lower floors or at other fixtures nearby. Listen at the (rarely-used) tub drain. Do you hear gurgling or bubbling?

Keep us posted - it'll help other readers and might also permit a smarter comment.

On 2012-03-26 by Ted Kierzyk

Got a question for you. Just started hearing a hissing noise coming from the master bath tub drain this morning.
This tub is rarely used and we have a septic system. No city drain. Any ideas what this might be & should I act quickly and get a plumber out there today?
Thanks in advance for your prompt response.

On 2012-02-28 by Judy Baca

I have a knocking noise in one of the sinks in my bathroom whenever the heater comes on. It is a heat pump. Can you give me any clues as to why?

we had yhe tank pumped but we still here this noise when the toilet is flosh

On 2012-02-07 by (mod) - signs of inadequate drain venting include noises


The noise you describe is often caused by either inadequate drain venting (or a blocked vent) or by a partially clogged main building drain. In the second case, water runs down the drain until it hits the obstruction then slows and "gurgles" as it makes its way through the partial blockage.

Wade: there may be another cause but I've seen the bubbling toilet drain behavior you describe when there was inadequate venting and on occasion in response to a blocked drain. If you're pretty sure the vent is ok and if none of the drains in the same bath ever seem slow or blocked,

I suppose it could also be an artifact of the particular toilet tank and flush valve. Take off the toilet tank lid and look into the tank during flush - is there a lot of agitation of the flush water mixing air into the system as water leaves the tank and enters the bowl? (It's cold water, not hot, right??)

On 2012-02-04 by Mark

After running the water in our bathroom sink, the water drains out completely, then a couple seconds later, we hear, "glub, glub, glub." It lasts only a couple seconds and is gone. The bathroom is on the ground level, and we have a finished basement, if that means anything.

On 2012-02-01 by Wade

When I flush my old American Standard toilet the bottom of the bowl at the beginning of the flush lets a couple of air bubbles up. It does this every time, all drains seem to work and no other problems than it just seems wrong.

What is with the air bubbles at the very bottom of the bowl on the front side of the toilet. Please solve this mystery nobody else can and it is only when I flush. We flush and listen for sucking of other drain pipes to see if that is a clue the main stack vent is plugged but everything seems fine. Help !

On 2012-01-23 03:19:48.853998 by Joe

When the second floor toilet is flushed, a loud almost grinding or whining noise can be heard in plumbing -coming from somewhere between basement and second level.

Nose is delayed by about 20 seconds after flushing, and lasts about 10-15 seconds. Unsure of cause, just started. In freezing climate, will head to roof to check vent as a start - any advice?

On 2012-01-06 by (mod) - clogged drains and glub glub sounds,

Mike: re clogged drains and glub glub sounds, I've posted our discussion in the FAQs above. Take a look at CLOGGED DRAIN DIAGNOSIS & REPAIR (links found at the INDEX to RELATED ARTICLES near the end of this page) for suggestions on how to proceed.

On 2012-01-06 by (mod) -

Louis, I've moved our discussion of noise complaints around a V-200 anti-siphon valve up to the FAQs section of the plumbing drain noise article just above. Further questions & comments are welcome.

On 2012-01-04 1 by (mod) -


Presuming that there are normal distances between your patio and the neighbor's plumbing vent roof pipe, what you describe is unusual. I wonder if perhaps the neighbor has

- a problem with their vent system leading to gurgling?
- a new high velocity low-water using flush toilet?

You might ask the neighbor if flush noise is a problem inside their own home, or if there is a drain problem - if the answer is no to both cases, ... well I've asked for additional thoughts from our noise and sound expert and we'll follow-up here.

On 2012-01-04 by Bonnie

We have a covered patio that faces the side of our neighbors house.

We can hear his toilet flush through the vent pipe on his roof. Is that normal? We have never noticed it in other houses we have lived in where our outside space was in close proximity to our neighbors bathroom vent pipe. It is so annoying and embarrassing when we are outside. Is there anything we can have our neighbor do to eliminate the noise? Thanks, Bonnie


Continue reading at PLUMBING DRAIN NOISE REPAIR - home, or select a topic from closely-related articles below, or see our complete INDEX to RELATED ARTICLES below.

Or see CLOGGED DRAIN DIAGNOSIS & REPAIR - clogged drains may gurgle or burp

Or see PLUMBING VENT NOISE - since vent problems can cause gurgling at drain lines

Or see this

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