There are a number of reasons you can get an odor from a kitchen sink. One is a trap is loosing its seal everytime it is used. This happens because either the vent is clogged on the kitchen sink, or there is no vent. Every time you put water into the sink, it has to push the air ahead of it, because they both take up space. As the water in the trap develops a syphon, it pushes the air ahead of it down the drain. If the vent is clogged, it creates a vacuum after the water passes with has to be refilled with air. If it can't take it from the roof, then it will take it from the garbage disposal. So what has this to do with odor? Well the air that it draws in from the kitchen sink (rather than the roof) completely sucks the trap dry. Every trap is supose to have a cup of water in the bottom, that prevents air from coming back up from the sewer system. With no water in the U-shaped bowl of the trap, sewer gas is free to come back up into the home.

Another odor from kitchen sinks is mold, which can take place inside walls behind cabinets.

Good Luck

Raymond

Raymond VinZant Plumbing Prof.