Sewage ejector pump was installed in finished basement bathroom. Sewer smell emanates in house at different times. Not always. On occasion (infrequent) when pump goes, a little water backs up though the washing machine line.

The ejector pump has a vent, looks to be vented to the side of the house. A sink and shower drain to the ejector, the washing machine does not. The drains work fine, when I run the sink, the water in the shower trap does move slightly up and down. I am trying to find out if this is a venting issue... and advice how to eliminate sewer smell would be greatly appreciated

And now you can tell me about your vents, Are there any AAV's installed? You should have a vent off your lavatory that revents back into the house system and a dedicated pit vent that doesn't connect to anything. Is that what you have? Let me know, Tom

Yes... I am pretty sure... the Pit Vent looks like it exits side of house on first floor... not 100 % sure though it may tie back into to main vent stack (there is only 1 main vent stack in house)... the main house vent was not re-installed properly when roof was completed... once we fixed this vent... the smell was reduced quite a bit... however we recently had a new sewer injector installed and the smell now is seemingly worse than ever... only on occasion... it is almost a damp swampy smell as opposed to a sewer smelll

Check that pit vent and get back with the results. If It's been revented back into the house vent you've located your problem., m Good luck, Tom

Check that pit vent and get back with the results. If It's been revented back into the house vent you've located your problem.,,m Good luck, Tom

The vent line runs 3 right angles... one about 2 feet above the pit to the wall than up the wall than up seeming to a vent opening in the side of the house... I will try to test with a hose tomorrow

I teste the pump again, and the when pump ejects, water comes back up through the drain for the washing machine... just a little seems to bubble up... the washing machine does not drain to ejector pit... confusing... thanks for any help

If you have to pump the sewage up to the main then how does the washer discharge up to the main since the washer isn't draining into the pit? Please explain. Back to you. BTom

If you have to pump the sewage up to the main then how does the washer discharge up to the main since the washer isn't draining into the pit? Please explain. Back to you. bTom

The washing machine is higher than the drain and always drained into the main prior to the bathroom remodel and ejector pit being installed. My guess is they just left that line as is..

Thanks again


The washing machine is higher than the drain and always drained into the main prior to the bathroom remodel and ejector pit being installed. My guess is they just left that line as is..

Thanks again

Also I did test the vent with hose and the ejector pit is definitely vented to the side of the house. Thanks again

Here are some pictures... thanks again!


Also I did test the vent with hose and the ejector pit is definitely vented to the side of the house. Thanks again

Here are some pictures...thanks again!!

A few more pix

when pump ejects, water comes back up through the drain for the washing machine. You just told me that you have a partial blockage downstream from the washer. It's going to take quite a but of back pressure to back water up a 3' washer stand pipe. At the same time you have enough backpressure to give the water a 3 foot head you also have enough back pressure to expel sewer gas. I think you've just located the source of your stinky. I also see duct tape around the pit vent opening. Is sewer gas leaking from the connecdtion? Snake ( Not the hose) the drain line from the washer and see if old stinky doesn't go bye bye. Good luck, Tom

Yes and put all those wires in a junction box!

What is the duct tape for?

The seal to one stack was a little loose... slightly... the duct tape helped the seal...

The washing machine drain connects at a 45 degree angle to the ejectors descending line to the main. It does not drain to ejector pit. Shower and sink do not have dedicated vents just drain to the pit.