Sewer smell

[leahbenn7]

When we run our air conditioner units they blow in a sewer smell from rear AC - we have capped sewer vents but when wind blows you get the sewer smell - any suggestions of what else to check?

[wildmandmc]

Had this happen to me a few camping trips ago. Went outside an could smell it. Drained blk tank, then grey/galley tank. Short time later prob gone. Tanks were not full.
Is this happening all the time?
I read somewhere, that there is a vent flapper somewhere. perhaps it got stuck in the open position. << This happen on a 5'er.

[Lt Dan]

Check for AAV (Air Admittance Valves) under your bathroom sink. The odor could be coming from the gray tank which can be worse than the black. Failed AAVs is a very common problem. A way to test is is to cover it with a plastic baggie tied tight and see if the odor goes away. It may look similar to below.

[rag_ftw]

If you have a washer/dryer it can also be coming from that drain line.

[ArtJoyce]

Originally Posted by Lt Dan

Check for AAV (Air Admittance Valves) under your bathroom sink. The odor could be coming from the gray tank which can be worse than the black. Failed AAVs is a very common problem. A way to test is is to cover it with a plastic baggie tied tighting and see if the odor goes away. It may look similar to below.

+2 that was our issue. I bought enough new air admittance valves to replace all in the camper.

Also, if a trap becomes dry you will have an odor. In this warm weather if you are not using the shower or sink they can dry out. Add 2 cups of water to each trap.

[chuckbear]

What do you mean, you have "capped" vents? Does that mean your vents are closed off? We had a problem with sewer smell in the coach after never having a problem in the past. Wasps built a nest in one of the vents and it became almost totally closed off. After clearing it out, the problem is gone. Chuck

[leahbenn7]

It ended up being the washer unit and turned it on a cycle - seemed to help- thanks

[rag_ftw]

Originally Posted by leahbenn7

It ended up being the washer unit and turned it on a cycle - seemed to help- thanks

Good troubleshooting!
ALWAYS do the easy/cheapest stuff first!!