After dumping the tanks from camping this past labor day w/e, I noticed a really funky smell inside the trailer when I went in to add water and chemicals to the black tank. Almost a sewage smell.Ive never had any odor issues inside the trailer before.(its only 2 years old) I was still parked at the dump station when I went inside and noticed it. Couldn't smell anything outside. The smell was definitely coming from inside the trailer.Any thoughts on where it may have come from and why it happened? Maybe other have experience this too.

Did you have a vent open with a fan on?? If you did, when you opened the drain in the toilet, it will suck the vapors out of the tank into the bathroom.

No vent open, no fan on. I noticed the odor as soon as I walked into the trailer. Wasn't even to the bathroom yet to add water to the black. The place where I dump is an RV Dealer about 10 minutes from my house. It's about 20 miles from where I stayed this past w/e. (I like going there because there is hardly anyone there when I go and I can take my time and do a real thorough job rinsing the black tank.)

Make sure that you run a little water in all your sinks and shower. If the water in the drain traps has evaporated, any stink from the dump station will work it's way right back up into your rig through the plumbing if you open the gray water dump valve.

There should never be any sewer odor inside. Because you just used it, I will assume the traps have water. So I would check to see if you have check valves under the sinks instead of through the roof vents. They are notorious for causing problems like this. I hope you find it and its an easy fix.

powderman426 wrote: Because you just used it, I will assume the traps have water. So I would check to see if you have check valves under the sinks instead of through the roof vents. They are notorious for causing problems like this. X2 on the check/vacuum breaker valves... but I wouldn't assume all the traps had water. I recall hearing about an instance where a vacuum breaker stuck in the closed position and dumping would suck the water out of a couple of traps...

wheres that smell coming from? | Good Sam Community

29 Replies

rondeb
Explorer
Oct 03, 2013
We had a terrible odor and finally figured that it was from our shower drain. We never used the shower and the P-trap just became dry and was allowing the sewer smell to come into the RV.

Easy fix. Just pour water or we use "pink stuff" down the drain
bguy
Explorer
Oct 02, 2013
My TT has an Automatic Vent for each fixture including the bathtub. There's an access hatch on the front.
DE88ROX
Explorer
Oct 02, 2013
Well, last weekend was our last trip of the season. Orchard Beach State Park. On the shores of Lake Michigan. Manistee Mi. Anyone heading to the upper lower of Michigan and looking for a new place, check it out.

But anywho... Prior to dumping I checked all my traps, went about my routine at the dump station. went back inside and checked all traps again. No odor and all the traps had water in them.

This has only happened twice since buying the trailer new in 2012. Guess ill just chalk it up to be one of those things that make you go Hmmmmmmmm.

Thanks again for all the advise!!!

Think spring!!!
campigloo
Explorer
Sep 13, 2013
Did you give a teenage boy a big bowl of beans just before you left? LOL
DE88ROX
Explorer
Sep 13, 2013
Bobbo wrote:
DE88ROX wrote:
Thanks for all the input. I will definitely keep an eye on the traps before my next trip to the dump station. Which is in about 3 weeks!

After, after. Check AFTER your trip to the dump station. That is when you can tell.

Gotcha!
Bobbo
Explorer III
Sep 08, 2013
DE88ROX wrote:
Thanks for all the input. I will definitely keep an eye on the traps before my next trip to the dump station. Which is in about 3 weeks!

After, after. Check AFTER your trip to the dump station. That is when you can tell.
Old-Biscuit
Explorer III
Sep 08, 2013
Did you look under the kitchen and bathroom sinks for air admittance valves?
DE88ROX
Explorer
Sep 08, 2013
Thanks for all the input. I will definitely keep an eye on the traps before my next trip to the dump station. Which is in about 3 weeks!
Bobbo
Explorer III
Sep 07, 2013
Actually, there are not that many places the odor can be coming from.
1. sink trap (or shower trap) with no water
2. bad AAV (can also lead to #1)
3. no water in toilet bowl
4. bad seal of toilet to tank
5. bad seal of vent to tank, either black or gray
6. odor from roof vent being pulled back into RV
7. blocked roof vent

I had #7 that lead to #2 that then lead to #1.
Bobbo
Explorer III
Sep 07, 2013
If by dumping, the water is pulled out of the traps, your AAV is bad. If by dumping, the water is NOT pulled out of your traps, you have to investigate further. That is a simple test for one of many possible causes of the odor. That test failing does not point to any one other problem, it merely means the AAV is probably good.

If the AAV is bad, the act of dumping, itself, drains the trap.