Washing machine drain suds overflowing

Had a client this morning describe a problem for which I have no answer. So I thought I would post it here.

The problem:
When the washer drains they get suds, not actual water, overflowing from the drain opening. While no water comes out, it is of course wet.

They have had the builder out, who has supposedly for some reason scoped the pipe and confirmed no blockage.

They have had an appliance guy out who says everything is fine with the machine.

They have changed soap brands/type and amounts.

They brought the washer with them when they moved and did not have this problem in their old house.

While I can think of a number of reasons for this drain to back up and overflow, I can’t come up with any for it to cause just suds to overflow. The circumstances seem to indicate that it is a problem in the drain plumbing. A vent problem?

Any ideas?

Sounds like their using too much soap.

They tell you that they cut down the amount, but did they really?

I’ll bet it’s the soap amount.

Dish washing soap instead of dish washer soap will do it every time .
Try washing with no soap and if the water runs away I expect this is the reason.
… Cookie


Do you think they could be that idiotic?

Could also be their water hardness. Did they have “hard” water at their old home, and this home has very “soft” water? You can usually get “free” water hardness test strips at Lowes…just ask for them.

Yes seen it done more then once .
I give up on trying to be sure people do not make mistakes .
If it can be done some one will do it.

I have not lost the sugar yet but my grandmother did found it in the freezer.


In my younger years, my new wife and I tried regular dish soap in the dishwasher when we ran out one time. It was truly hilarious, and looked like a skit from an old I love Lucy show. Suds all over the kitchen. I even ended up having to take the dishwasher outside, and hoseit out, because rincing just made more suds. Idiotic? No, just ignorant. Sometimes what you don’t know, can be pretty funny.

What I don’t understand is that they didn’t have the problem in their old house. But now that they moved, there’s suds everywhere.

Whatever they were using and doing at their old house, I’m sure they brought their washing habits with them.

I’m baffled…

Hard water will not produce suds if real soap is used.

A simple test for soft water is to add a drop or two of real soap to a small vial and shake.
If it’s soft it with suds nicely.
If not there will be little or no suds and the water will be cloudy after shaking.

Detergents however will suds in soft or hard water.

I cannot say with absolute certainty how much or what type of soap they are using. I saw the laundry detergent box for what they use now. They say they are not using too much - who knows on that front.

I suggested all the basic things like running it a few times without soap, running some vinegar through it to help remove buildup, etc.

I don’t think this is a water thing, as I have lived around here for 25 years and worked in inspection or related businesses for 15 or so and never heard of this paritcular complaint.

My best advice was to get one of those newer drain hoses that have the molded rubber plug type thing that caps the drain and holds in the hose. I figure that will keep the suds in.

I wonder as said above they are comming from very hard water needed lots of soap now softer water needs less soap.
yes as you said run it no soap and see what happens .
… Cookie

Mr Weiss,
Is the washer drain entering into a standpipe? If it is, what is the length and diameter of the standpipe? Also if using a standpipe what is the distance from the trap of the standpipe to the 1st unobstructed vent?

I have seen short standpipes and flexible traps that were buried inside walls create this issue. The ridges on the flexible buried trap creates turbulence and excess suds. Also every time i have seen this it has been a 1.5" dia standpipe.

Hope this helps

Why be so quick to question a homeowner? Should look for a real solution.
We recently had the same problem and worked with our plumber to create a “test” drain with the exact same specs as the drain pipe in the wall. Still a gallon of suds overflowing in the test drain that had no obstructions (had exact same drain pipe and p-trap, but draining into a bucket). A tablespoon of liquid detergent for a large load in a top-load machine is NOT too much detergent. Same detergent used for 10 + years.
Comments that dismiss valid problems as being simply user error don’t help anyone.

There seems to be some confusion here about whether this a dishwasher or clothes washer, the OP’s reference to laundry makes me think we are talking clothes washer. Further to Don Peterson, where is the drain, in the floor? Is there a standpipe? Are suds coming out of the floor drain after draining into a stand pipe nearby, or are they backing up in the standpipe? Is the machine in the basement or in an upstairs laundry room? How old is the house? We need more information.

Drain pipe not high enough. Need a pic.

The thread is 7 years old Roy.

Darn! I didn’t pay attention.

There is no demand for a blind inspector that don’t pay attention to details:twisted:

But the problem is still not fixed…:wink:

That way I don’t havta write as many thing up. LOL !