Washing machine stinks!

[username_taken]

My washing machine smells like a sewer plant after the load is finished. I don't notice a smell when the machine just sits, only right after doing a load (smell & load used so much in one post ). Any idea of where it's coming from? The laundry is on the second floor of the house. I'm wondering if the odor is coming in from the plumbing vent. But that wouldn't make sense given that it's setup like all other machines- drain pipe out of the machine travels up a good 2-feet before it makes 90 degrees and comes to rest in the PVC drain pipe coming out of the wall. I frankly can't see a way for odor to make it from the vent to the machine with such a configuration; the drain pipe just sits in the PVC pipe, so no way air is going to work its way through a pipe with a sharp bend, then down 2 feet and into my machine. I can understand some smell, but this machine truly reeks when it stops and you open the door! Am I missing something? I've run bleach through it when doing whites and it still smells. The water is the same water that goes throught the whole house, and it doesn't smell. Any ideas?
Thanks

[Rhubarb]

What you have described is quite puzzling. It doesn't make sense, but the smell pretty much has to be coming from the plumbing vents. All I can think of is that the machine is creating a partial vacuum, perhaps during the spin cycle, that is pulling vapors from the vent stack into the machine.

The reason it doesn't make any sense is that the drain should be trapped, which would prevent any vapors from coming up from below, and since you've just drained the washer into it, the trap should be filled.

I'm not quite sure exactly how to test this theory, but I might try running an empty machine on the spin cycle and seeing if the drain hose is pulling air into the machine. If it is, your drain may not be trapped. If that is the case you might be able to create an external trap with the drain hose by allowing it to drop about 6 inches before looping up to the drain.

[Will Repair]

90 degrees or 180? Got to be 180!

I take it the drain is not sealed.

How is the rest of the upstairs plumbing? Toilet harder to flush? Bathtub take a while to drain? Or is everything still as it was before you noticed the smell.

Sure the smell is sewer? I googled 'washing machine smell' and got quite a few hits about washing machines that get smells, even from soap deposits.

[Jeep's Phoenix]

Do you use liquid fabric softener, by any chance? It can build up in the dispenser and get really nasty after awhile.

[username_taken]

Will Repair : 90 degrees or 180? Got to be 180!

- sorry, yu are correct, it is a 180 degree bend .

Jeep's Phoenix : Do you use liquid fabric softener, by any chance? It can build up in the dispenser and get really nasty after awhile.

never.

The plumbing is all fine. The smell is definitely a septic smell (like opening a septic tank).

Rhubarb : All I can think of is that the machine is creating a partial vacuum, perhaps during the spin cycle, that is pulling vapors from the vent stack into the machine.

I thought this too, but can't see it happening. There is no closure around the drain pipe when it goes into the PVC wall pipe- the thing just slips into it with a gap around it. However, it does go pretty far into the PVC wall pipe, about 6 inches or so. I suppose, in theory, that just enough air from the vent stack could be drawn up the drain pipe to cause the smell. But, the smell is pretty strong. Well, I'm truly puzzled by this. The machine is used a LOT (usually at least a load a day, sometimes 3), so I can't see any kind of septic process taking place in it. Hmmm...

Thanks for your ideas everyone. I'll post the answer if I figure it out.

[Rhubarb]

Originally Posted by username_taken

I thought this too, but can't see it happening. There is no closure around the drain pipe when it goes into the PVC wall pipe- the thing just slips into it with a gap around it. However, it does go pretty far into the PVC wall pipe, about 6 inches or so. I suppose, in theory, that just enough air from the vent stack could be drawn up the drain pipe to cause the smell. But, the smell is pretty strong. Well, I'm truly puzzled by this. The machine is used a LOT (usually at least a load a day, sometimes 3), so I can't see any kind of septic process taking place in it. Hmmm...

Thanks for your ideas everyone. I'll post the answer if I figure it out.

You missed the point. If the spin cycle is creating a suction on the drain hose, you WILL get sewer gas in the washing machine if your drain is not trapped. You wouldn't notice the problem at any other time since the gas would rise up the vent stack and exhaust outside. Even then, there wouldn't be much under ordinary circumstances because there wouldn't be anything pulling it up the stack. It would only be a factor if something was actively drawing a suction on the line. It bears looking into.