Foul Odor in the House, P-trap Dry?

A P-trap is that “P” shaped pipe in between the sink and the drain going through the wall.  It is designed to hold water in the “P” shaped portion to block out foul smelling sewer gas from wafting up through your sink into the room. This P-trap concept is on your shower drain and floor drains as well.  

Suppose you have a bath or utility tub that is not used often or maybe the home has been vacant for a while.  The water ‘seal’ in the P-trap will evaporate allowing the stinky air from the sewer to get in the room.  It can be a difficult smell to diagnose because we don’t often think of a dried out P-trap being the culprit.  I’ve had vacant homes for sale with this issue. 

The good news is it is super simple to fix. Just turn on the water for a few seconds and the P-trap will fill up and again block the sewer gas from entering! Feel free to reach out with any home inspection or real estate related questions that come to mind!