I live in a two story house built in 1978 hooked up on sewer. When the clothes washer is used downstairs there is a sewer smell in the upstairs bathroom. I did not notice the smell was while the washer was used early on. So I have replaced the wax seal under the toilet. All the sinks,toilets , showers drain as they should. What should be my next step of elimination? Thanks in advance for reading my post and any suggestions.

If the washing machine discharges and you have the sewer smell it could be caused by a blocked vent and the washing machine is causing negative effect

In other words the seal of the traps upstairs are being compromised by back pressure and puling water (trap seal) out of the trap

Make sure all traps upstairs have water in them. Also, make sure all plumbing fixtures have traps. Look under sinks and shine flash light into shower drain. There should be standing water

Back to you

Milo

I agree with tieger plumbing, it is most likely a blocked vent. Call a professional to check it out if the problem persists.

Hey guys thanks for the replies. Recently I have had both vents on top of the house snaked 50ft. Ran water down both as well. Also snaked the clean out 50ft. We intended to snake the washer discharge pipe as well but the snake was to big. The smell in the upstairs bathroom is still there once the washer is used. Any other suggestions would be greatly appreciated! I look forward to any responses. Thanks


Make sure all traps upstairs have water in them. Also, make sure all plumbing fixtures have traps. Look under sinks and shine flash light into shower drain. There should be standing water

Back to you

Milo
Checked and all the traps upstairs do have water in them. Any other suggestions would be greatly appreciated.
Thanks

Tenman,
Are you connected to a central sewer system or a private septic system? My first step would be to open the soil pipe / sewer main cleanout to see if the same odor is present in the lowest portion of your dwv system.

I suggest performing a peppermint test - if there is a leak in your dwv piping it is easier to trace the more pleasant odor trail of peppermint; you can control the amount & timing...