I have a new home: about 3100 sq/ft, two story, slab on grade. It's now about 4 months old, but since the first week of moving in, when running the dishwasher or washer (laundry), the house fills with the smell of sewage. Both the washer and dishwasher are brand new units. I had the plumber come out, because I believed something was not properly flushed, etc. He told me the it was because the traps were dry and that I need to run water in all the traps everyday. I've been running all the trapped sinks, etc. in the house for a few minutes a day and it doesn't go away. I had the plumber back out and he said the same thing, that the traps are dry. I explained that I run the sinks, tubs, showers in the house everyday, and he basically said I am lying. I haven't had a second opinion yet, because I feel like this should be covered under the plumbing warranty. Does anyone have any ideas of what the problem could be? Maybe, the plumbing isn't properly vented somewhere? Perhaps something wasn't cleared properly? I'd love some ideas to go back to these guys to make sure they do or find the problem. I mean, it's pretty embarrassing to have people come over and only to be overwhelmed by the smell of sh....
You should not need to run water in all of the traps everyday to prevent them from drying out .... that is nonsense. The job of the vents is to prevent the traps from siphoning dry. If the traps are actually dry, it could indicate a problem with venting. There may be other possible causes of the smell as well. You should not have to figure out the problem yourself. I would go directly to the builder / whoever you bought the house from / whoever is responsible for the home warranty and indicate that the plumber has failed to resolve the problem. Be persistent and direct. Indicate that if he is not able to resolve the problem promptly, you will call in an independent professional to diagnose the problem, and pursue compensation in small claims court.
Can you see a trap on the WM standpipe? (It could be in the wall if the whole thing is finished.) IF the vents are installed properly, when you run water through a drain it will not affect the other traps. If things aren't vented properly, running water, especially fast on something like a WM, it can suck other vents dry. As mentioned, a trap might dry out via evaporation, but that would takes weeks, or maybe even longer, not in a day or less.
Thanks guys. I appreciate it. It didn't make sense to me either, as at my old house I had a bathroom that was use once a year, and I never had the problem.
I can't see the WM standpipe, as the walls are all finished.
I'll go back to the builder and push the issue more.