The house I live in is 14 years old and is connected to the municipal water and sewage system in the Toronto, Canada, suburbs. I am on my second dishwasher. The first one was a cheapo Whirlpool, the current one is a mid-priced Miele. Nothing too fancy, but not cheap too. Both of them have the same issue: after it rains, or while it rains for a long time, the dishes and glasses/cups come out stinking of rancid fish.
None in the household was ever able to feel any odors from tap water. And we do not feel any odd smell from the sink drains or from the toilets. We never had sewage backup, knock on wood.
What was suggested to me:
- That the drainage pipe out of the house and into the sewage could be cracked, and rainwater may be pushing sewage gases up the drain. But I would imagine the stench would be felt from the sink drains as well. We do not feel any of that. And the issue started as soon as we moved into the new house.
- That rubber gaskets in the dishwasher have deteriorated and let wastewater stagnate in the joints. I am also having a hard time buying into this theory, as both dishwashers had this issue since brand new.
I found a workaround with the new Miele dishwasher - if I stop the cycle right after the rinse is complete and before it begins to heat and circulate air out and into the drainage, the smell is either reduced to a minimum, or not there at all.
It also helped to add about 1 cup of white vinegar to the water once the cycle fills the pan. The smell was reduced, but not removed completely.
And finally, the smell was reduced significantly after installing the whole house filter from Vitasauls. The smell was horrible very often before that, and now it is noticeable only after it rained for a while.
I have a suspect, but that is inconclusive: the pleated drain hose of the dishwasher sounds like a perfect spot for breeding bacteria which arrives with the tap water, contaminated during the rain. But what can I do, if they all come with pleated plastic hoses?
I know that this is a very widespread problem with no one-size-fits-all resolution, but hoping for suggestion from anyone who experienced the same.
The picture below is very similar to my installation, both in the design of the sink drains, and the path of the drain hose to the stem on the drain pipe: