Sewer Smell

[Jackfrostspam64]

We have an odor coming from the washer room. The city did a smoke test and smoke can clearly be seen coming from the washing machine box. Can a missing trap be the only explanation for this? Or is there another possible cause? Possibly no vent and the trap water being sucked out? They use the washer 3 times daily.

 

[Twowaxhack]

Missing trap, wrong kind of trap, compromised trap.

One or a combination of all three.