: In our town we have been experiencing some very bad sewer gas problems. However, only does the sewer gas seem to become evident when it's rain either very hard or for long periods of time. This past week we have had terrible rain and the problem seems to persist. We replaced the trap so we know that that isn't the problem. Is there anything else that could be causing our gas crisis? Please reply.
Just a theory but your venting may be trapping water which will plug it off.Venting is usually graded upward to prevent this,if your venting is backgraded or if it is sagging it could be collecting the rain water causing the traps to siphon.