There is a sewage smell coming from my bathroom. What could be wrong?
You don’t specify if the smell is there all the time or only if you run water. If it happens only while the hot water is running, you may have bacteria growing in the water line. Otherwise sewer smell is usually caused by water in the p-trap under the sink dropping below the point where the water forms a vapor seal. Make sure the p-trap is perfectly level under the sink and does not leak. Also check your toilet to make sure the water level is not unusually low. This would indicate a hairline crack in the internal toilet trap allowing water to leak until it is below the vapor seal mark.
We commonly receive question regarding smells in the bathroom area. You may want to remove the P-trap and clean it out. Often the trap will become partially obstructed and that will effect the vapor seal, not to mention the smell that will emanates from just the gunk in your P trap. It is not difficult to affect these clean up job. You simply need a large wash bowl to place under the trap to catch the water that drips out as you loosen up the connect to remove the trap. These trap can be removed with your hands, you do not require a plumber wrench or any other tool. Once you have taken it off, check to see the condition of the trap and clean it out thoroughly. While the P-trap is one culprit that you should check to see the you vent stack leading up to the roof is operating properly. Sometimes animals like squirrels or even birds will nest up on top of the vent piple that leads through the attic and out to the roof line. Any interruption in the flow of sewer gases out through the vent pipe will cause the odor to back up into your bathroom.