Your association should be responsible as the drain is inside the wall. Soap is made of fat and it clogs the drain but not so much that it backs the water up. This soap is food to bacteria and becomes a slimey moldy mess that emits awful fumes. Remedy: Your association needs to have the plumber pull the drain hose (you would be wise to replace it) and clean the drain. Then fill your washer with hot water and 1/2 a gallon of clorox. Once it fills and starts to wash, turn it off and let it sit for 10-15 minutes. Turn it back on and let it run through the cycle. I did this twice with bleach, then once with 1/2 gallon of vinegar and last with an entire bottle of Febreeze. I also saturated clothing in Febreeze (old towels) and put them in the dryer (odor hit the dryer because it's a stackable). If that doesn't work it may be the roof vent which is for sewer fumes, something a plummber must also deal with. Do not let your plummer push you around - mine swore it wasn't the drain and was stunned when it was. I had to fight him to make him pull the washer and check it.

If that doesn't work, it may be one of the things I eliminated in the process of finding the washer drain.
*I checked for old aerosol cans that might be leaking and pitched them and old paint/chemical cans.
*I ran water in all drains and sinks and shower to make certain there was water in my P-Trap (U shaped pipe under your sink that fills with water preventing rotten fumes from coming in your house).
*Had the water department confirm there were no clogs in the main.
* I called the fire department and they confirmed there were no combusitble gases. The odor hit them before they got in my front door and said they had never smelled anything like it. FYI...rotten eggs is what a meth-lab smell like according to them. If your neighbors are cooking and dumping it down the drain...well. You should call the non-ER line of the FD and have them check if the washer drain doens't do it).
*I had the association clean the dryer duct (this too is inside the walls and mine is legally responsible for cleaning this annually as it is a fire hazard).

I hope this helps.

Michelle In Orange County

: Help! I live on the 3rd floor of a condo building and the pipes leading to my washing machine stink badly during a wash cycle. Weird thing is, its not consistent - it seems to occur more often in the cooler months and not at all during summer. What the heck is going on? My HOA won't do anything because no one else reports this problem - not even the guy directly below me. I'm on the top floor - could that have something to do with it? Any advice would be greatly appreciated!!
: Thank you.
: Michelle
: San Diego, CA