What is the purpose of vapor traps?

Every water fixture in your house has a vapor trap. This "U" shaped pipe is clearly visible under sinks, and is present in some form on all lines draining to the sanitary sewer system. The "U" shape holds water, preventing gases from backing up from the sewer into the house through the drain.

Show All Answers

1. What causes blockages to occur?
2. Does it make a difference how much water gets into the sanitary sewer system?
3. What causes sewer odors inside the house?
4. What is the purpose of vapor traps?
5. What is the purpose of a roof vent?