Sewer smell inside Trailer but no in bathroom

Snowbunny

We purchased a 2023 Tab 400 Boondock from sellers.  They only used it twice and it sat for approximately 8 months without being used.  We took it to a campground in Florida for two nights.  It was very hot out so we used the AC the whole time.  First day we noticed a sewer smell in the trailer but not in the bathroom.  Next day the smell was worse but still not in the bathroom.  We have checked all over and cannot seem to find where the odor is coming from.  Any ideas?

pthomas745

If this is a sulfur smell, you need to check your batteries ASAP!  Overheating batteries can produce hydrogen gas that can smell like rotten eggs. 

If not: check the status of your gray tank.  If the tank is empty, it can produce some smells from various things biodegrading in the bottom of the tank. 

In general, what do you use for tank treatments? When (or if) have you ever sanitized the fresh water system?

elbolillo

@pthomas745 Since it is a '23 Tab 400, more than likely it has a Battleborn LiFePo4 battery installed. It would not be giving off a sulfur smell.

Any chance there is some kind of critter that has made a nest in some part of the Tab? Have you checked under the cushions by the air conditioning unit?

bergger

Are you hooked up to sewer at the campground?  If so make sure you have the black and gray tank valves closed.  Last year we were hooked up and I inadvertently left  the black tank valve open while hooked up.  After a while I noticed a terrible sewer smell and could not figure it out until I closed the black tank valve.  I guess the smell was coming up from the sewer connection and out of our black tank vent.  

Binghi

The odor likely is coming from the black tank. It’s possible that the previous owners did not treat the black tank water or emptied the tank and did not put in a new gallon or so of water to keep any leftover solids from drying out. A dried-out dirty black tank will stink like hell.

I would flush the tank out thoroughly several times using a hose wand or large container of water in addition to pumping a bunch of water through the Nautilus black water tank hose connection. Then prime the tank with 2-3 gallons of water along with a dose of black tank treatment like Happy Camper. Repeat if necessary.

pthomas745

@elbolillo Ah!  Thanks!  I had this on my mind this week as a "boiling battery" caused a couple of houses to be evacuated on my street for a couple of hours. 

Basil48192

I had the same issue in my 2021, 320S a few weeks ago.  I would open the door and immediately smell, what seemed to be, a raw sewage smell.  I keep my T@B very clean and always flush and sanitize.  I searched every crevice for water or any other source of the smell.  Everything was dry, clean, and odor-free.  
It turned out that I had a small propane leak from my stove.
Now, I know what propane smells like...and this did not smell like propane!.  However, when combined with the 'normal' smell of the closed up camper, I would have sworn it was stagnant water or sewage.
I found the tiny leak at the gas manifold that fed the burners and repaired it. 
No more smell!
I hope this helps.   

rh5555

Another place to check is the condensate drain from your A/C - make sure it is draining properly and not clogged.  Stagnant water can get to smell pretty bad...

WayneW

@Basil48192. I wonder why your propane detector did not go off. It seems like that should have detected the leak. A buildup of propane gas inside the trailer, a small spark and …….

enzo86

we are also chasing a non bathroom smell that seems to be coming from under the stove area. I can smell it pretty strong when we open the cabinets under the stove on our 2022 T@B 400.  I know it is not propane as we keep it off when not in use.

Basil48192

@WayneW.  Thank you!  I had the same thoughts.  But I never left my propane valve open when not in use and, once I detected the smell, I didn't leave it until I found the issue (same day).  Though it was enough to produce a smell when I first opened the camper door, I'm guessing that I never left it long enough to accumulate enough propane to trip the monitor. 
When I found the leak, it would barely form tiny bubbles in the soap solution that I applied (see the red arrow in the photo below).  It was a very tiny leak, but it was definitely the problem.  That being said...I am definitely going to check the monitor.  

@enzo86.  I didn't think mine was propane either because I could smell it even when the main valve was closed.  But, I found there was enough propane trapped between the valve and the burners to leak for quite a while...if it's a very tiny leak as mine was.  I would definitely check it.  Mine was a pinched or melted silicon rubber washer on the propane manifold 'saddle clamp' (yellow arrow in the photo).  The smell hasn't returned since I repaired it.  Hope this helps!