When the weather turns cooler or cold, our laundry room drain emits a very bad odor- like rotten eggs only worse. This has been happening for several years. What causes this?

I think your vent stack is slowly plugging up and you need to rod it from the roof. Before doing this insure that all drains have a p trap including a washer and that the traps have water in them. The water seals the trap preventing the gas getting inside. Slight chance your vent is cracked near the laundry. When we are in the heating season most homes have a slight vacuum caused buy the furnace or boiler. This vac pull on the sewer gas and your windows are closed so you aren't getting fresh air.

Why did you let it go on for SEVERAL YEARS ? I have lived in my house for seven years and have my washer and dryer in my kitchen. The only time I have had a bad odor is when I have left washing in the machine in the very hot weather. I just wash it again and put it in the dryer.

Tickle, did you read the whole post, she said the drain emits the odor.

Sorry, bellanger, but sometimes noses are not quite accurate, you, I did read the whole post... exiting stage right and waving...

It could be the vent but try this first. Most bad smells in tubs, lavatorys and showers are caused by rotting hair matted with grease from the soap and from rotting food in kitchen disposals Try this for the smell. Tonight before bedtine Take a 1/2 gallon of bleach and pour it down the drain and let set over night. Next morning ,(and this is important) flush out the drain with two large pans of boiling water to loosen the grease and flush the mess out. The bleach will make the hair slippery and began to dissolve it and the hot water will melt the grease and flush the mess away. Good luck, Tom