The problem of sewer regurgitation was found

The problem of sewer regurgitation has always been a nuisance. This year, I stayed in the new house on the floor, and every night the smell came out, and it appeared from time to time, and I felt that the bathroom was getting more and more smelly. Repeatedly looking for the taste of the taste, just can not find.

Later, after analysis, it was found that it was a problem with the smoke machine and the exhaust fan. Now the family, doors and windows are closed well, a smoke machine and exhaust fan are turned on, where does the air intake come from? Doors and windows can't come in, only through the sewer mouth. Therefore, if you need to open a smoke machine or exhaust fan, you must open a window. The problem is solved. I hope it will be helpful to my friends, but my family's problem is solved anyway.