No popups, no spam.
Folks helping folks with
respect.  You'll like it. -- The Home Page of the Finishing Industry
  HomeFAQsBooksHelpWanted Mar. '16AdvertiseContactForum Letter 29544

The Hotline: Serious Education ... plus the most fun you can have in metal finishing. Ted Mooney, Webmaster

Washing machine drain line backs up

An ongoing discussion from 2004 through 2016 . . .


Q. I have a washing machine drain line that over flows when the washing machine dumps its water, I have to stop the machine allow the water to drain off then allow machine to continue, On a full load I have to do it several times, I have paid to have a power auger clear the line but after a few weeks its backing up again, what can I use to clear the drain? Is Muriatic Acid [linked by editor to product info at Amazon] ok to use on a cast iron drain pipe? if so how much do I use.

Jeff S [last name deleted for privacy by Editor]
support service - Huntsville, Texas


A. Acid is not appropriate for metal drain lines. Lye type drain cleaners like Drano [linked by editor to product info at Amazon] or Liquid Plumber are more appropriate, although dangerous to people. This isn't a plumbing forum, but have you considered the possibility that roots have penetrated your drain piping? If so, new drain lines is the answer. Can you put a sock or stocking, or more formal filter in the discharge to capture the lint? Is it possible that you have created an air lock in the drain?

Ted Mooney,
Teds signature
Ted Mooney, P.E. RET
Pine Beach, New Jersey


Q. My washing machine floods my floor with water when it is draining the tub water. The hose is in place in the drain pipe but the water fountains out the drain pipe. I have put a garden hose down the pipe drain, no water flows back. There is no blockage. What could the problem be?

Irene B [last name deleted for privacy by Editor]
- Oak Harbor, Washington


A. Well, seeing as I have the same problem myself, I guess I'm an "expert" :-)

I used duct tape to connect the drain hose to the drain pipe so the water can't escape -- see if that helps. Not the right answer, of course, and may void your warranty -- but it works for me on my decades-old Maytag.

Here's the real problem probably: all drains require vents and your washing machine drain may not have one. Your bath, toilet, sinks, basins, all have vent pipes going up through the roof. When water needs to go down one of those drains, it just pushes the air that was in the pipe up the vent pipe. When you have no vent pipe, there's no place for the air to go to get out of the way of the water, so it has to "push back". Why doesn't the air just go down the drain pipe to get out of the way? Because air is much lighter than water, it keeps fighting to "float" back up the pipe.

Ted Mooney,
Teds signature
Ted Mooney, P.E. RET
Pine Beach, New Jersey

Plumbing for Dummies


Q. So how do we stop this air /water problem from happening?

Thank you STEPH ~

Stephanie Z [last name deleted for privacy by Editor]
- Selden, New York


A. Hi, Stephanie. You have your plumber put in a vent pipe, which is probably required by plumbing code anyway -- or you live with it, duct taping things to minimize the leakage :-)

Ted Mooney,
Teds signature
Ted Mooney, P.E. RET
Pine Beach, New Jersey


Q. Like the person before, I too have a drain problem. The 2" drain line ties into a 3" drain line. The 3" line has a vent. It seems to my calculations that the backup is at the 2-3 inch joint. This is a 3x2 combo sanitary tee. The 3" line is clear (I know this because it is also a drain for another washing machine in the adjoining duplex.). What could be causing the back up?

James Crapitto
- Huntsville, Texas

Q. Our washing machine backs up, not into itself, not further down the line, but into the kitchen sinks! My wife has to stop the machine, wait for the water to gurgle down the sinks, and then restart the machine. This she does a few times until the washing cycle is done. The drainage system appears to be in a T-formation, with the kitchen drainage pipe continuing down toward the bathrooms, and the washing machine connecting about in between the kitchen and bathrooms to form the "T".
Would sincerely appreciate some help and advice.

Manuel S. Gonzalez
- Benbrook, Texas

Q. Having the same problem and I know I need a vent pipe on my washing machine. Where should it be placed to allow the air to escape?

Tracy Gordon
- Odenville, Alabama


A. You can see better drawings in a home handyman book, Tracy, but every plumbing fixture including a washing machine should have a trap and a vent. Good luck.

Ted Mooney,
Teds signature
Ted Mooney, P.E. RET
Pine Beach, New Jersey

Air Admittance Valve


A. Look into an Air Admittance Valve =>
This will let in air without have to run a vent up through your roof. Sure old timers will tell you this is "band-aid" plumbing but sometimes you can't vent up. Just remember the AAV will go bad at some point so make sure it is accessible. They are simple to add. Of course you should check to see if it is 'allowable' by the code in your area.

Chris Cook
- Parma, Ohio


A. I had the same problem but it turned out to be roots. Watch out for trees near your sewer line. They always are the main problem. I have worked for a Public Works Department for 30 years so you think I would have figured this one out.
But no, the trees were 50 ft away.

Richard Maag
- Edmonds, Washington

February 2009

Q. My washing machine drain is also overflowing. I have air vents to the from the main line 5 ft away. My old washing machine never overflowed. My newer Maytag does. I am told that it is the size of the drain line. My house built in 1975 has a 1.5 inch drain line from the washer. I am told that the newer washing machine force out water a lot faster than the older machines...and now need at least a 2 inch drain line to handle the newer flow rates. It sounds right. I wish there was a way to reduce the machine flow rate, since I must knock holes in my block wall to replace my old drain.

What solutions have the experts come up with?

bob pendleton
- Tempe, Arizona

March 2009

A. Regarding washer machine drain problems. I just installed a Studor Mini-Vent today and am hoping this corrects the problem. I had to cut into the 2" line and install a tee in order to do this, but it was very easy.

If this doesn't correct the problem I am going to install a laundry tub and allow the washing machine to drain through it. This should slow down the water drainage and hopefully solve the back-up problems that we have been having as well. I have tried snaking the drain, about every type of drain cleaner and nothing worked. We also had an older washer and never had any problems until we had to replace it with a new one.

I will update this to let you all know if the mini vent works or not.

R Beavers
- Dallas, North Carolina

March 2009

Q. I've got this problem as well...after a mess up on my part (broke the drain stack off the main drain in the crawl space while trying to check it out) we've replaced the old 1.5" to 2" drain stack that was already there with a 2.5" stack...and we're still having the problem...though it's not as bad (with the old stack water would shoot out of the top of the stack like a it kind of just bubbles)....during the drain cycle on the washer I can stand at the pipe and if I hold the washer's drain JUST right and wiggle it a little I can get it to not overflow (though it comes close) once it does start to drain back down I can hear a distinct gurgling in the this indicative of a venting issue? I've got a feeling that it's just a vacuum issue (though our plumber did suggest getting the lines snaked)...

David Senette
- Knoxville Tennessee

April 2009

A. Most of the drainage problems espoused here could be simply resolved by eliminating the usage of tub-type washers and employing front loaders. The latter use 1/3 the water of a top load machine, and using less of anything is a good thing these days. One-third less in, one-third less out.

Simple, but difficult and unreasonable if your top loader was a recent purchase. Replacing an older machine will pay for itself after several years -- less water, less water to heat, plus more gentle action on your clothing.

Rory B. Saillant
- Lake Worth, Florida

May 2009

Q. Our washing machine leaks intermittently. The repairman is stumped after coming out twice as there is no sign of a leak in the machine or where the outflow drains in the back wall. We think it may be occurring only after multiple back to back loads. Could water be backing up into the pan somehow from the pan drain? If it matters, this is an upstairs machine.

Brady Pregerson
hobbyist - Carlsbad, California

June 2009

Q. My name is Mary Jo and I have a similar issue with my machine. When I attempt to fill washer once it gets to certain height it starts running right back out drainage pipe of washer. Another words my tub is not holding the water its running right back out.

Mary Jo Davies
homemaker - Albion, New York

August 2009

A. When water comes right out of the washer as it's filling, it's a sure thing your hose is too low. this creates a siphon which pulls water down to the level of the outlet of the hose.

Solution: raise the hose. it should dump water at or a little above the level of water in the tub. measure from the start of the tub opening to the top of the washer, measure from the top of the washer to the floor, and subtract the smaller number from the larger. that's the height the hose outlet should be.

It will be higher on a top loader than a front-loader, unless you have an unusually high pedestal. washers have a small drainage pump that will make up the difference.

scott schrader
- mounds view, Minnesota

October 2009

Q. My washing machine used to drain the water completely.
I am using a Liliput washing machine. Suddenly, the drain stopped working.
There is a wire kind of thing given inside to pull it up so the water drains out.

When I pull this thread, its draining. Otherwise water is staying inside the tub itself.

I am not sure, if there is any blockade inside. How can I fix this issue?

Please suggest me.

Thanks, Sathish

Sathish Kumar
buyer - India
January 15, 2010

Q. I have been having the same exact problem with my washer! The "back-up" thing, that is. The house I just bought was built in 1947 and the new washer just backs up as soon as it drains. The pipe cannot handle the amount of water flowing out of the washer because it doesn't get enough air. They also didn't vent as many places as they do now. So, my vent is over the kitchen and the washer is about 6 feet away.
We have taken the pipe off, snaked, used a "water weenie" and ran 2 hoses full blast through it and it drains, when I try to use the washer, it comes out like a fountain. Luckily I have a window over the area and I quickly stuck the hose through it to finish my laundry.
There is this thing that my cousin has on her drain that seals it completely when the hose is in there and apparently they are commonly used in older homes. I am going to try that because the P-trap in in the wall and I don't want to rip it out yet until I re-drywall the garage. Has anyone else used one of these and do they work?

Denise Tucker
- Sacramento, California
April 1, 2010

Q. I also have he washer drain pipe that is backing up on the water discharge cycle. We have been in the house for 3 years, built around 8-9 years ago. never had a problem before but after doing 5 loads one day it backed up on the 6th. It does drain once the washer is stopped, and the vent is right above the washer drain. I have snaked it as far as it would go, dumped drain cleaner, etc. without any change. Any suggestions? Thank you

Don Pysz
- Imperial, Missouri

April 18, 2010

A. My washing machine has also been overflowing out of the drain tube. The wall rotted, I tore out all the rot, replace the 2 x 4's with pressure treat, and instead of using sheet rock in the laundry room I decided to use plastic bathroom board.

I have a 25' snake. I snaked the p-trap and came up clean. I went on the roof and snaked the vent as best I could - came up with mud looking stuff and hair.

I ran water hose full blast through the drain and through the vent and it did fine - however, the washing machine still backs up.

To reduce the flow rate I took the rubber drain hose off and stuck a metal washer in there - at the end where it connects to the washing machine - the metal washer is large enough so that it won't fall into the washing machine and won't get pushed through the drain hose. It fit perfectly and reduced the hose size about a third - and it was enough to fix the problem.

I sealed all the gaps at the drain / water supply box with Great Stuff expanding foam, and used caulking to seal all the base boards so next time it overflows it will stay on the tile floor rather than being able to sneak back in the wall.

Brian Elton
- Baton Rouge, Louisiana

April 19, 2010

Hi, Brian. Different installations have different problems, but to me it sounds like in your case you still have an air-lock despite the main vent. Picture this, although perhaps exaggerated:

If a pipe has any unvented high spot, air will collect in it. Think about what happens when water tries to flow in such a pipe: the only way water can go into the air locked area is by driving the air out. But how are you going to push that air -- that so desperately insists on floating -- down below the water at the other end of the air lock? You can't. If you have a situation anything like what is pictured, you have to fix the routing or have a vent at the high spot to let the air escape from the pipe. Good luck.


Ted Mooney,
Teds signature
Ted Mooney, P.E. RET
Pine Beach, New Jersey

April 27, 2010

A. I fixed the same issue for a neighbor

She bought a new washer that discharges water at a higher rate, causing her drain line to overflow. I cleared the line about 15 feet or so and no luck. I tried every way to fix it but just came to the simple, but not as neat, way of discharging the water into a plastic mop sink with a p-trap discharging into the drain line. This does the job and adds a mop sink in your garage and if you need to soak,clean etc you don't need to go to the kitchen. Do not discard chemicals or paints down the mop sink, not good for your cast iron or the ocean.

MOP SINK: $49 dollars plastic hardware: $15 dollars little bit of cutting and connecting handyman/plumber: one to two hours of labor. 25 to 80 per hour...all though you can do this yourself easy. ask your local hardware/home improvement personnel.

you might have to relocate the washing machine and dryer: extra hardware/material....not much but this will add to the labor per hour part. If they know what they are doing just two hours max

Rudy Repreza
- Orange, California

April 27, 2010

A. We bought a newer washing machine and our drain could not handle the flow, it would back up in the sink and overflow. We have 2" diameter drain pipes and vents. Finally solved the problem by renting a power snake, the one that works like a power drill. Threaded it as far as it would go, locked it and slowly went back and forth to clean the walls of the pipe. The drill motor rotates the snakes which beats against the pipe walls cleaning them. Slowly did this in one foot intervals. Locking the snake, pushing in and out, unlocking withdrawing a foot or so, relocking and pushing in and out with the drill motor rotating, until the hole drain was done. Takes some time and effort, but it did the trick, cleared drain and only cost $22 to rent the power snake. Note: Threaded the snake through just below the sink drain in our case. Good Luck.

Bob Clark
- Kent, Washington
June 2, 2010

A. I had this same problem and puzzled on it for six years. I tried everything. store-bought drain cleaners, home-remedy drain cleaners, plumbers, boiling water, everything. then it finally dawned on me that the flow rate from the washer was more than the drain pipe could handle. I bought a washer drain hose that was narrower than the one on my machine. I clamped one into the other, effectively reducing the flow from about 1 1/2 inches (in diameter) to about one inch. this worked instantly and cost me about nine dollars.

now I just need to replace all that rot caused by this problem. wish me luck.

mike drago
- dallas, Texas, USA
July 1, 2010

A. House is 72 years old. It has copper pipe that goes into cast pipe. The 2 inch drain from the washing mashing connects somewhere under the kitchen sink. We figured this out by removing the kitchen sink clean out and running the washing machine. Water came out the kitchen sink drain clean out... We snaked it and the problem appears to be solved. Note. We had to remove the short extension on the kitchen sink drain clean out to get the snake to go down the pipe. We also flushed water down the pipe and watched debris go by at the septic side.

Hope this helps....

John Bostrom
- Georgetown, Texas, USA

August 31, 2010

Q. We have a 30 year old home, that we've been in just over a year. We discovered that the washer discharge was backing up, I installed a venting device and I believe it helps on the discharge backing up, but we discovered accidentally that when we flush the toilet in the basement, the washer discharge pipe backs up, - but not all the time. We tried flushing it while the washer was discharging, and it backed up as well even after installing the vent.

The toilet discharges into a sump pump in the crawl space of the house, the sump pump discharge line joins into the washer discharge line under the house which goes to the main sewer line out the front of the house. The sump pump has a vent line that goes out to the back side of the house from the crawl space. The discharge line also has a vent pipe under the house to a small sewer vent in the crawl space as well.


Not sure what my next step is beyond asking for help here, possibly calling a plumber next, unless someone has another possible solution.

William Baggett
Homeowner / handyman - Atlanta, Georgia, USA
October 6, 2010

Q. Can you give me a solution of backup of foam only from washing machines drain? we bought a new whirl pool Cabrio washing machine and only foam backed up a few months later. Try different cleaners and snake. Water drains ok. I do not think we put in too much liquid detergent. Our house was built 22 years ago. Never have foam problem with old washer.Thanks for any suggestion.

Junhai Zhang
homeowner - Parma, Ohio, USA

October 16, 2010

A. I have a problem with my washer drain water backing up into my double kitchen sink whenever the washer drains. I have been told to install an Air Admittance Valve, and I am not sure whether I should
(1) install it under the kitchen sink
(2) I could simply connect to my washer drain pipe (with a sanitary "T" in the drain line, then connect a 90 degree elbow to this "T" and then attach the Air Admittance Valve to the top of the 90 elbow.

Any advise on this situation would be greatly appreciated.

F. Ross Kennedy
- Halifax, Nova Scotia, Canada

October 18, 2010

Hi, Ross. Although they call it an air admittance valve, I think they also let air get out of the line so the water can flow through it. As such, I think the ideal placement would at the high point of the line.^[See entry of Jan. 18, 2012]


Ted Mooney,
Teds signature
Ted Mooney, P.E. RET
Pine Beach, New Jersey

October 24, 2010

Q. Our Kenmore washing machine is draining the water but bubbles are backing up the drain. how do you stop this?

Joe Kraus
home owner - USA

October 25, 2010

Q. Hose that goes into washer drain, the water keeps coming back out when the washer drains the water. We have snaked it and put drain cleaner in it the snake seems to only go so far then stops?

Barb Nobile
homeowner - Gahanna, Ohio

December 1, 2010

A. GVii valve is a patented product that pressurizes the drain which keeps it clean and attaches directly to your washer hose. For more info go to my web site Thanks

Randy Jirasek
- Troy,Texas USA

December 1, 2010

Hi, Randy. Good to hear that you have a potential solution. But I'm not seeing in your posting or on your website an explanation about which of these problems it addresses or how. Since it is patented you should be free to explain exactly what it is and how it works so the readers can judge how likely it is to solve their problem. Thanks.


Ted Mooney,
Teds signature
Ted Mooney, P.E. RET
Pine Beach, New Jersey

December 1, 2010

The GVii is a valve that has a stainless steel check ball. When the washer is pumping out, ball comes up, which makes built in air brake. It prevents hose popping out and overflow of drain pipe, and helps keep drains clean. Hope this helps! Thanks

Randy Jirasek
- Troy,Texas

December 9, 2010

Q. I have the same problem, and snaking the washer drain line does nothing. However, I have an air vent pipe that goes to the roof, which seems to be the issue. If I snake the vent pipe, the problem goes away for 2-3 weeks. Any thoughts on how to make this more permanent? Does the pipe go straight down to the drain, so I could pour drain cleaner down it? Thanks in advance for any solutions.

J McLaughlin
- Torrance, California USA

December 10, 2010

A. Our second floor washing machine began overflowing at the drain after a new pump was installed in the washer. Tried everything from snaking to the expensive camera down the line to find the issue. No problems, vent on roof was fine too. Augured down the line 75 feet to no effect.

What finally worked was installing a 45 degree piece of pipe to a y valve. The drain line now drops 2.5 feet to a trap, the trap comes up and the line goes about six inches across to the 45 degree piece then into the y valve where it connects to the vent pipe going up and also drops down into the wall of the house.

Jeff Stratton
- Ankney, Iowa, USA

January 19, 2011

A. The biggest issue with all of the above seems to me (or to be) that the volume of water used by older machines, is replaced by a larger volume of water used by the newer machines. Most of the pipes can handle the larger volume, but not at the same DISCHARGE as the newer machines. If you SEAL the gap from the machine to the drain line, eventually you have no air in the system.... eventually the water runs freely. While duct tape works, there must be a way to PLUG the drain hose into the line and seal it, solving all the problems.

Gabriel Holter
- gulfport, Mississippi, usa

January 27, 2011

A. Most of the problems I have been reading here are due to improper plumbing connections and assemblies. The plumbing code specifically states that every trap has to be vented properly. Air admittance valves can work but do have the potential of failing. Location of the washer trap, height, length and height of trap arm and proximity of other plumbing fixtures, such as water closets and bathroom groups, can and do affect the performance of the washer drain. Only an experienced licensed plumber can identify if such plumbing drainage systems to be properly installed, either preexisting, altered or installed.....

Steve Maldonado
- Georgetown, Texas, USA

Uniform Plumbing Code

February 12, 2011

A. Like most people I have also had this problem and found out that the soap we were using had a waxy type substance that was visible on the soap fill area. What worked was using a bacterial drain cleaner =>
which now I use a different soap and use the bacterial cleaner from time to time. Previous to this I put 170 degree water at full flow and the snake, the bacterial cleaner worked.

Brian Carlton
- Okanogan Washington

March 12, 2011

Q. I bought a washer a couple of years ago brand new, had to put it into storage, and now it isn't wanting to hold water, and it is all coming out the bottom.

michele quinn
student - cedar park, Texas USA

Bacterial drain cleaner

March 21, 2011

Q. I'm having this same issue. When the water goes to drain from the washing machine water spews out of the pipe behind the machine. Same machine I have had for 5 years and all of a sudden this happens. I can't figure it out...doesn't seem to be clogged. Please help someone ... I can't afford a plumber right now. Thanks in advance.

L Hall
- Houston, Texas, USA

May 15, 2011

Q. I have lived in my house for 15 years it was built in the 50's never had an issue now all of the sudden my washer,kitchen sink and bathroom sink are all backing up into my toilet. I do have a sump pump in my crawl space. We have rooted all the lines and rooted the vent on the roof. Nothing is seeming to help! I do have trees 2 in front 1 in back could it be roots?

Cindi K
- Lake Station, Indiana

May 16, 2011

A. Hi, Cindi.

You need a professional plumber to look at this. Sad to say it could be very bad. Many 1950s tract houses used the least expensive, and often unproven materials like drain pipes that were essentially cardboard steeped in tar.


Ted Mooney,
Teds signature
Ted Mooney, P.E. RET
Pine Beach, New Jersey

June 18, 2011

Q. I have the same problem,
October 16, 2010

I have a problem as Ross Kennedy's
"my washer drain water backing up into my double kitchen sink whenever the washer drains. I have been told to install an Air Admittance Valve..."

I am not familiar to this system.

Would you please let me know of the detail steps to fix this problem?


Woo-Young Yoon
- Pleasanton, California, USA

July 15, 2011

A. I had this problem in my house 30+ years ago. the house was built in 1935 and had 1 1/2" galvanized pipe for a drain for the washer. I reduced it to a 3/4" pipe which fit snugly into the washer drain hose. I also "T"ed off it and put in a directional valve with a clapper in it, so that air could get into the line but water could not get out. This allowed the washer to pressurize the line and force the water into the drain system. It was easy to do and worked for about 25 years at which time I replaced all the plumbing while remodeling the kitchen. what I found when I removed the old galvanized and cast drain lines was really ugly! I could not even see through them they were so corroded. I replaced the washer drain with 1 1/2" abs and it works great.
If you use too much soap it can also fill the drain line with too much bubbles and the water cannot get past it as it should.
New washers use less water than the old ones did, but drain faster due to higher spin speeds.
Another problem I have seen that slows drains is blocked roof vents, wasps or birds building nests in them.

Bob Petersen
- Orinda, California

August 20, 2011

A. I want to thank all of you for your suggestions. I made a list of the ideas that I wanted to try before calling a plumber. 1. Lye, gel type drain cleaner 2. Enzyme type drain care, build up remover. 3. Power drill plus snake. 4.restrict drain water flow from machine. 5. call a plumber 6. buy a new front loader machine.
We bought a new machine 3 years ago and had no problems until about 6 months ago. We just recently noticed that the drain was overflowing into the crawl space beneath the house. I checked the drain hose by running a cycle and having it drain into a trash bucket. I knew then the problem was in the plumbing. Luckily, I was able to clear the drain using 1, 2 & 3. It took me a week and cost about $45. Don't give up. The enzyme type drain cleaner took 3 applications. I ran boiling water thru after allowing the enzyme type drain cleaner to sit overnight. The last thing I did was to run the power drill auger through and that pulled up some hair. Good luck !

Frank Walsh
- Dunwoody, Georgia, USA

August 24, 2011

A. Our drain problem has been solved!! We are so happy. My husband inserted a 1" pvc pipe into our drain hose before the drain pipe. It diffuses the water, slowing down the amount of water into the line. We haven't had water on the floor, since.

Annette Pallowick
- Indian Harbour Beach, Florida, USA

September 7, 2011

The same thing happened to my 2 year old machine. All of a sudden it is leaking water were the machine hose and pipe meet. My machine does not wring out water, GE said it is because of my pipe being not big enough. Why did the manufacturer never mention that there is a possibility to have this problem. They should have given us size of pipe drain not just us finding it out of the blue.

Erlinda A [last name deleted for privacy by Editor]
- Carson, California USA

September 22, 2011

Q. Hi. My name is Megan. I live in housing authority which is public housing. When I run my washer I have to stop it in mid drainage because the water is backing up into my kitchen sinks. I have had them out eight times for it and all they do is snake it. But it continues to do it. I was told that it could be that someone from the other apartments is draining grease down the sinks and it is clogged at the drainage u-bend right before going into the sewer. Now I have asked all of my neighbors and none of them do it and none of them is experiencing the same problems. What should I do about this problem and how should I go about telling Housing about it without sounding bossy or mean? Please help me. I am at my wit's end with this whole situation.

Megan Brooks
home renter - Elkhart, Indiana USA

October 26, 2011

A. A couple of months have passed since I fixed the drain in the wall behind the washing machine. I just wanted to report that everything is still working well. We have switched to a liquid detergent. We had been using a powder. The powder has a waxy feel to it and could be the culprit in clogging up the pipes.

Frank Walsh
- Dunwoody, Georgia

October 26, 2011

Thanks for the feedback, Frank. We often wait a long time, or in vain, for the 2nd shoe to drop :-)


Ted Mooney,
Teds signature
Ted Mooney, P.E. RET
Pine Beach, New Jersey

November 6, 2011

A. Amazing how many have the same problem. My front-load washer broke and I bought a top-loader. From the first use, water was backing up out of the drain onto the floor. I noticed the hose for the new machine was larger in diameter than the old one (1.25 inches vs. 3/4 inch).

I bought an attachment that went over the drain pipe and over the end of the drain hose and clamped it. Sealed the connection and now I have no problem.

Jonathan Richards
- Queens, New York, USA

November 14, 2011

Q. Can you please give me more information on what type of attachment you bought and where did you buy it?


Brad Phares
- Albion, Indiana, USA

November 17, 2011

Q. I have a 1.5 inch drainage pipe for my washer machine. They recommend 2inch for drainage pipes. When I wash my close, I have to pause it to allow the water to drain out. If I don't then water would fill the pipes and get on the floor. This didn't happen with my older washer machine. What would you recommend.

Marcus Pipes
- Indianapolis, Indiana

November 22, 2011

A. Just fixed this problem myself. No vent needed. The drain pipe on the washer is thin plastic so I just pinched it inward and put a hose clamp on it to reduce the volume of water that drains. The crease also allows the air to more readily escape the pipe solving the vent problem. Yes, I tested it and it still drains super fast. Sweet!

Scott Anderson
- Brandon, Mississippi, USA

December 19, 2011

Q. I found this "blog" & hope someone can help. Ted, do you do plumbing locally? The issue is this, we have a rental condo that we have never had a problem with the draining of the washing machine before (have owned the unit for approx. 13 years & had numerous tenants in that time) The washer that is there now has been there for several years, with no problem. After the last tenant moved out, I pulled the washer out to clean behind it, did not have to disconnect anything to do so, but obviously the drain line was moved around. The new tenants did a load of wash and found that during the drain cycle, the water started to come out of the pipe where the drain hose from the washer goes in. He went & bought a new rubber seal type attachment for the drain hose, but it still leaks. We went down and snaked the line, didn't seem to have been clogged and then ran a hose into the drain pipe at full speed and the water drained out perfectly. thinking we must have cleared a clog, re-hooked everything up and again, as soon as the washer drains, the water fills the drain line and starts leaking out the top. We did notice that there had been tape on the connection before,was no longer in place, do you think we should try the duct tape method? Could there be an air lock that once the water forces through will then flow correctly? Any help would be appreciated

Beth McCarthy
- Bayville, New Jersey, USA

December 2011

A. Hi, Beth. I run this metal finishing website, which occasionally rambles into side topics like air locks, but I am not in the plumbing business and I know very little about it.

I duct-taped my own washing machine drain, but I'm sure this is discouraged by the washing machine manufacturer, as well as not really being the right answer. But it does sound like you have an air lock which you need to either have fixed by a plumber putting in a vent or at least an air-admittance valve, or live with by taping the hose. Good luck.


Ted Mooney,
Teds signature
Ted Mooney, P.E. RET
Pine Beach, New Jersey

January 8, 2012

thumbsdownTed, you should not give advice outside your area of expertise. Vent pipes or air admittance valves allow air into the system to prevent the traps from being siphoned and allowing sewer gas into your home. The air lock you describe should never exist in a properly designed system...the drain lines must always be sloped and never have a high point in the middle of the line. Furthermore, washing machines discharge indirectly into the drain pipe for a reason. By taping it up you are essentially creating a direct connection which is a code violation.

All of these issues are caused by one of two things....either the drain pipe is undersized and can't keep up with the discharge rate of the washer, or there is an obstruction in the pipe (clog, broken pipe, or roots) which is preventing it from draining properly.

James Ledyard
- Atlanta, Georgia, USA

January 2012

thumbsup2Thanks for clarifying the anti-siphon purpose of those valves, James. I have more respect for the skills and experience demanded of a plumber than you know: My father was a master plumber, and in those days you had to be able to beautifully solder-wipe a lead pipe joint to the full satisfaction of a 3-man "drill sergeant" certification board to pass the test. So when I was a kid there was an iron pot of solder cooking on the big propane burner in the basement almost nightly for a year as he practiced for that piece of the test, as one small part of his decades of experience and study.

I told the very first poster that this wasn't a plumbing forum; and I told Beth and others repeatedly, "I am not in the plumbing business business and I know very little about it".

Engineer's flow chart: Does it move?

  • Yes
    • Is it supposed to?
      • Yes => No problem
      • No => Duct Tape
  • No
    • Is it supposed to?
      • Yes => WD-40
      • No => No problem

I don't think anyone in the world believes that duct tape is a proper solution, and I thought I made it clear, again & again, that I know that duct taping the washer discharge hose into the pipe is completely wrong and discouraged by the washer manufacturer, but I did it as a desperate fellow homeowner with wet floors who couldn't afford to have a plumber run larger drain lines. In any event, it should be crystal clear on this go 'round that I'm not offering engineering or professional plumbing advice, just sharing tips with fellow homeowners who also can't afford to have bigger drain pipes installed.

But, yes, I have seen drain piping installed just exactly as I illustrated, with an air lock because someone thought they could run a drain pipe over the basement curb around their old coal bin instead of through it; I didn't make it up; it's where I learned about air locks, and why I warn other amateurs about them :-)

My job entails the obligation to courteously respond to people's questions to the best of my limited ability if no one else answers ... it would have been rude to ignore them and leave them hanging for 8 years until you showed up, so perhaps you shouldn't give advice out of your area of expertise either, advising website administrators to just leave posted questions unanswered if they are not professionals :-)

Thanks again, and regards,

Ted Mooney,
Teds signature
Ted Mooney, P.E. RET
Pine Beach, New Jersey

January 11, 2012

A. Of all the solutions and remedies in here there's one that was very easy and fixed the problem I've been having for years. That of placing a metal washer that restricts the flow of water enough to let the drains keep up. I'd suggest using aluminum or galvanized one that won't rust. There are probably other methods such as tapering the washer drain hose down to a quarter or half an inch. It doesn't seem to hurt the motor, water pump, or interfere with the timer. The washing machine still empties. I'd imagine there's a water level sensor or something to let the machine empty even though it takes a bit longer to do so.

It wasn't my idea; thanks to Brian E - Baton Rouge, Louisiana for the suggestion above.

Fred Young
- Ellwood City, Pennsylvania

January 17, 2012

A. I would have to agree that the problem seems that the older homes (mine is over 30+ years) have smaller drain lines that cannot handle the flow rate. I reduced the flow by fitting the line with a homemade reducer... never thought about simply placing a washer in the fitting.... that seems easiest way possible. At any rate, it's been working for the past three years with no more overflow! Thanks for all the ideas!

Gabriel Holter
- Gulfport, Mississippi, USA

January 18, 2012

Q. Just bought a new top loader HE washing machine. The drain hose is too large in diameter than the drain pipe. Any thought on how to avoid a leak? I connected the former drain hose to the new hose with a clamp, but it still leaks out when the machine first starts draining. Any thoughts, please? thanks

Paula Johnson
- Bluffton, South Carolina, USA

January 17, 2012

A. My washing machine drain pipe was backing up. I spent $325 to have a plumber "Hydroblast" the drain line & clean out the trap. When that didn't work, the plumber wanted about $1,000 to tear out the drain pipe and trap & replace it with larger diameter ones. I felt the problem was the vent as the washing machine drain does not have its own vent. I bought a GVII Anti-flood valve from Jirasek Sytems Corp. It took about five minutes to install it and it fixed the problem. It may not fix every problem but it's sure worth $31.00 to give it a try.

Sid Burks
- Loma Linda, California USA

January 24, 2012

My house was built in the 1950's and I have a 2 inch cast iron stack for the washer in my basement that is not vented very well. I just bought a new top loader washer and was having all of the backup issues as everybody here. I had the drain snaked and the vent checked from the roof. Everything in good shape. I just went to Home Depot and bought an 8 inch long 3/4 inch pipe nipple that wiggled perfectly into the 1 inch opening of the washer drain hose. I clamped it with a ring clamp and tested it. It was slightly better, but still backed up. I then screwed on a 3/4 to 1/2 inch reducer to the end of the pipe nipple, also found at Home Depot. Worked perfectly with no backup. No idea whether this will hurt the pump, but my guess is that it won't in the near term. Good luck, everybody. This is my first time trying any of this btw.

Tyler J
- SW, Virginia

February 13, 2012

When I bought my new washer (top loader) I noticed it didn't have a lint filter like my old one did. I asked the salesman and he said I would need to put some drain cleaner down the washer drain every 6 months or so.

I REALLY wish I had gotten my old machine repaired instead of getting this new one. I have had backups into my shower of "blue jean lint" the last 3 times I have washed....despite the drain cleaner routine. Lots of gurgling in the sink & toilet too when the washer drains. Makes me wonder about new-fangled

Joan Taylor
- OKC, Oklahoma

February 21, 2012

We have very successfully used a double layer of Bridal Illusion [linked by editor to product info at Amazon], about 6-7" square, rubber-banded over the end of a 1 1/2" discharge hose into our basement drain. We change it after EVERY wash load. It catches the lint, and saves on plumber bills. And, yes, the hose goes up above the height of the discharge on the back of the machine before it descends and curves around to the drain. If lint is causing your drains to become clogged, this is a simple, cheap solution. You can make a LOT of filters from a yard or two of illusion! Hope this helps someone!

Lora McClamrock
- Fort Wayne Indiana, USA

June 25, 2012

Q. My washer also drains all over the basement floor. It did not do so until either we got the top loader or when the furnace & air conditioner drains were also placed in the washer drain. It's been a long time so I cannot recall when it became a problem.

I really think an Air Admittance Valve would work but I can't use one with the other items in the drain. What are my options?

Where else can the other drain tubes drain to? If I make them long enough, can I have them drain in the floor drain that's about 9 foot further over?

I really would like for this constant wet floor can be done with.

Tamie Petersen
- Battle Creek, Michigan, USA

June 27, 2012

Q. I read all the posts. I went with the solution the plumbers posted and verified it with a local plumber and the plumber that works at HD. Still did not fix the problem. There is no clog, I snaked it before beginning. Any solutions?

Michael Robins
- Shelby Township, Michigan

June 22, 2013

A. What I did to solve the problem was to extend the drain pipe up about a foot. That way it gathers enough water to push through the air long before it spills over. No problem since.

William Phipps
- Chicago, Illinois

September 10, 2013

Q. Washing machine drains into washtub, machine wasn't working properly only 3 months old, had repair man there and said to put a PVC pipe on the side of the washtub as it wasn't draining fast enough and created vacuum and was sucking the dirty water back into the machine, never heard of this before,
Was told to put a 2 inch PVC pipe on the side to create air flow, can anyone tell me if this is proper and if so the best way to attach it and what size to use?

Michael B
- Milwaukee, Wisconsin

September 11, 2013

A. Hi Michael. We can only guess what the repairman said to you, but if the washing machine's discharge hose is sitting in a tub full of dirty water, I suppose it could suck that water back into the machine.

I think he's telling you that the end of the hose must be above the water level in the washtub. It sounds easy enough to cut the hose as he said so the end is above the water level in your slow-draining washtub. Good luck.


Ted Mooney,
Teds signature
Ted Mooney, P.E. RET
Pine Beach, New Jersey

September 20, 2014

Well I live in a mobile home in a park; the sewage lines were backed up, but the lines are cleared out. Now when I do laundry my washer backs up into my tub and drains my toilet, but I can use the tubs, kitchen sink, and both toilets. Can someone tell me what to do?

wanda kruse
- cedar springs Michigan

September 2014

A. Hi Wanda. It sounds to me like the lines were only partially cleaned out and things are not draining freely (perhaps tree roots in the drain pipe).

See, the main drain line is supposed to be empty (full of air, not water). If you do not run any water for a while, any water in the drain pipe gradually seeps through the partial blockage and the pipe becomes empty. Now if you flush your toilet, the waste has some place to go (into the empty pipe), but if you keep running the water, the pipe gets filled because the waste is only seeping out, not flowing out properly.


pic of Ted Mooney
Teds signature
Ted Mooney, P.E. RET
Pine Beach, New Jersey

November 22, 2015

Q. I have mini vents installed in every bathroom in the house. Sometimes if I am running the shower and then the toilet is flushed, the toilet will overflow. What can be done to make the water flowing system independent so I don't have to go around telling people to not flush when showering or running any other water lines in bathrooms?

Kim Howard
- San Diego, California

January 11, 2016

A. The solution to stop the all the bubbles while the drain is happening is to ensure that the drain hose is firmly pushed down your drain pipe so that there's no room for bubbles. I had the same problem with slot of bubbles after the drain but once I firmly place the hose down the drain pipe, the bubbles were gone... Hopefully this helps.

Mark S. [last name deleted for privacy by Editor]
- Los Angeles, California

February 9, 2016

Q. My washing machine drains into a dedicated drain field. It had been on a slab outside the back door with the drain hose dumping into a 4" drain line that had a 4" vent stack. I laid a foundation and added a full laundry room in the same place. The vent stack was cut off, sealed and concreted over by the plumber who installed the wall faucet/drain unit. The machine drain hose still empties into the same drain line but now there is no vent. He also installed a laundry tub on the outside wall of the new room sitting right above the 4" drain line and tapped into that line to drain the tub (used 1.5" PVC but did not install a trap). Now when the machine drains, the water backs up into the tub. If venting is the problem I'm wondering why the tub drain line itself doesn't act as a vent? Would it do any good to install a vent line...and where? Thanks for any help or advice.

Unfortunately, the plumber is stiff-arming me about coming back to do the job right.

Vince Moore
- El Paso, Texas USA

April 27, 2016

Q. Hi,

We live in a flat. Every time the neighbour upstairs uses the washing machine (at least twice a day), our kitchen sink explodes, especially I believe when the water gets drained from the washing machine. It makes dreadful noises and stinks from time to time. I must admit their old washing machine never did that, it all started when they bought and installed a new one recently. It really has become unbearable, the water backing up to the sink every so often, with the drain bursting with the bubbles and smell. Could you please help resolve this issue. Many thanks.

Natela Bruce
- UK

April 27, 2016

thumbsup2I would like to thank Mr Mooney for this blog. I had drain problems and I am on a budget. Your info was right on and helped me greatly. I think that it is wonderful that you try to help people instead of just trying to get more money out of people that can't afford it. A lot of people are smart enough to figure it out with a little advice and guidance. So much appreciated. S

Susan R. [last name deleted for privacy by Editor]
- Anniston Alabama

April 2016

Thanks for the kind thoughts, Susan. Most of us can't afford to share everything, but can afford to share something :-)


pic of Ted Mooney
Teds signature
Ted Mooney, P.E. RET
Pine Beach, New Jersey

ADD a Q or A to THIS thread START a NEW THREADView This Week's HOT TOPICS

Disclaimer: It is not possible to diagnose a finishing problem or the hazards of an operation via these pages. All information presented is for general reference and does not represent a professional opinion nor the policy of an author's employer. The internet is largely anonymous; some names may be fictitious and some recommendations may be deliberately harmful.

  If you need a product/service, please check these Directories:

JobshopsCapital Equip. & Install'nChemicals & Consumables Consult'g, Train'g, SoftwareEnvironmental ComplianceTesting Svcs. & DevicesUsed & Surplus

©1995-2016     -    Privacy    -    Search
How Google uses data when you visit this site.