Recurring Sewer Smell when tanks are not full

[Hmbunk]

We have a 2020 Sandpiper fifth wheel and live in it full time. The last month we have had a few episodes of a horrible sewer smell in the kitchen/main area of the RV. The tanks are either half full or less than half full when this happens. We normally empty our tanks every few days and always put a tablet in the black tanks after flushing.
It seems to be coming from either the grey or galley tank. This morning it started, with the galley and grey tanks less than half full (we emptied last night). I went out and empty both tanks and the smell started to go away.

Can anyone help explain why this is now happening? It is very frustrating as I cannot handle our home smelling like poop!!!

[Flybob]

Do you have an inline vent under the sink? If so they can stick open. Simple easy replacement. See photo.

[ependydad]

Under the sinks is an air admittance valve. These often fail and allow tank gas into the RV. Quick and easy fix.

https://www.lowes.com/pd/Keeney-Plas...-Valve/1069119

[Thomas ho]

i put a plaatic bag over mine ,like a walmart sac. work great . have them on my mobile home valves also ,keeps septic odors at bay "away" "entrapped in a bag". "keeps the smell so far Away" must i go on!

[NMWildcat]

Originally Posted by Thomas ho

i put a plaatic bag over mine ,like a walmart sac. work great . have them on my mobile home valves also ,keeps septic odors at bay "away" "entrapped in a bag". "keeps the smell so far Away" must i go on!

That will mostly work unless you have it on tight enough to restrict air flow. Another option is to spend $7 bucks and replace it with a working AAV.

[5picker]

Originally Posted by Thomas ho

i put a plaatic bag over mine ,like a walmart sac. work great . have them on my mobile home valves also ,keeps septic odors at bay "away" "entrapped in a bag". "keeps the smell so far Away" must i go on!

Yes!... how does it admit air if you have it sealed off?

They are cheap... replace it/them.

[NJKris]

Grey tanks can get nasty. Hopefully you are careful to remove as much food debris as possible from dishes by scraping, wiping before washing, especially any animal fats, greasy stuff.

[ependydad]

Originally Posted by NJKris

Grey tanks can get nasty. Hopefully you are careful to remove as much food debris as possible from dishes by scraping, wiping before washing, especially any animal fats, greasy stuff.

Have you seen my kids do dishes? None of that happens.

[RobbieH]

Does your unit have a washer/dryer? In my coach I had the same issue and it was because the P trap for the washer was dry. Ran a load of clothes and problem resolved.

[NJKris]

Originally Posted by ependydad

Have you seen my kids do dishes? None of that happens.

I'm actually impressed your kids do dishes! Seems like most parents I know don't require their kids to do anything these days.

[Flipp]

Hi Hmbunk, I just had this same problem a couple months ago in my 2018 Sandpiper and replacing the air admittance valve fixed it. It was a PITA to get at it but an easy fix otherwise. I bought it at Lowes as others have mentioned...Flipp

[Danesville]

Try the Oatey Sure - Vent as they are great

[CaptnJohn]

Agree, change the valve! I have a bath and a half and have a spare for "in case". As far as the tablets~~ spme swear by them, I've not found any worth bothering with. I prefer the blue liquid and buy it by the gallon. Every 4th drain I use Campers, the powder that also works well. Don't forget the gray tanks too. Those are cheap compared to a stuck valve! You may want to wait until your tanks are 3/4 full or more to get a good clean out too. Lots of liquid to pull anything out is best.

[Hmbunk]

Originally Posted by Flipp

Hi Hmbunk, I just had this same problem a couple months ago in my 2018 Sandpiper and replacing the air admittance valve fixed it. It was a PITA to get at it but an easy fix otherwise. I bought it at Lowes as others have mentioned...Flipp

Thanks for all the input! I will for sure have the hubby check that out and get it replaced!!!

[lacamastraveler]

Originally Posted by Hmbunk

We have a 2020 Sandpiper fifth wheel and live in it full time. The last month we have had a few episodes of a horrible sewer smell in the kitchen/main area of the RV. The tanks are either half full or less than half full when this happens. We normally empty our tanks every few days and always put a tablet in the black tanks after flushing.
It seems to be coming from either the grey or galley tank. This morning it started, with the galley and grey tanks less than half full (we emptied last night). I went out and empty both tanks and the smell started to go away.

Can anyone help explain why this is now happening? It is very frustrating as I cannot handle our home smelling like poop!!!

I’m sure there were other replies but I didn’t go any further than Flybobs. We full timed for many years and when we experienced the problem you mentioned we just replace the filter he posted. Problem always solved.

[GFD47]

If your grey water tanks are really that nasty you might want to occasionally give them the same chlorine treatment that's recommended for your fresh water tank. The stuff that's creating that smell might not be all that healthy to have nearby.
Just sayin'...