Discussion Starter · #1 ·
House is on septic system. Tank is on north side of house but underground. Cleanout for the line to tank is also on the north side of the house. Sewer odors are only smelled when there is a north wind. 2 bathrooms. We have narrowed it down to the sewer smell only comes from shower/tub drainlines. Not the bathroom sinks, not laundry, not kitchen sink. We have tried everything. First we extended the roof vents higher, didn't work. Then we removed the vents from the roofline which was also on the north side of the house and replaced them with attic studer valves. Attic is well ventilated and has excellent air turnover. Then both bathrooms were remodeled and we found in both bathrooms that the p-traps were placed after the vent lines improperly on the tub/showers. Figured this was the problem since the sinks in the house all had p-traps under the basin which is why they weren't smelling. After both bath remodels with shower/tub p-traps and plumbing done to code, still getting the odor only when north wind blows. Only other thing we can think of is maybe doing a backflow preventer in the 4" line exiting the house to the septic tank but don't want to do that unless necessary. Any other ideas on how the odor is coming in?