Sewer smelly

Tghoover

Member
Hi all,

Full-timer here, and I recently noticed a sewer smell in the RV. I typically keep both my black tanks closed, and leave my gray tanks open and just dump the black tanks when they are full. I do a flush on them and add some of the RV deodorizers to the black tanks. I've done this for a couple of years. So this week, I started getting a sewer smell in the RV. I emptied the black tanks and did a rinse with bleach and water. I then shut all my tanks (black and gray) and the knife valve I have at the sewer/hose connection. The smell went away for a day and a half. The grey tanks started to get full, so I opened the knife valve (some liquid came out as the shutoffs probably aren't holding on my 2014 3875FB). I opened the gray tanks and drained them, and I left them open. In 5 minutes I had the sewer smell again. I shut everything again and the smell went away. I have made sure that all my traps have water in them.

Anyone have any thoughts on what this could be?

Thanks in advance! :cool:
 

travelin2

Pennsylvania Chapter Leaders-retired
Location of smell. Kitchen or bath ??
I recently had to replace the studor vent in the kitchen sink cabinet for that same reason. Stinky!!!!


Sent from my iPhone using Tapatalk
 

danemayer

Well-known member
Another vote for Studor valve as a possible cause. Kitchen islands for example often have a Studor valve instead of a vent pipe going through the roof. If the valve gets stuck open, odors from the tank get into the interior.

Another thing to do, because you have your gray tank valves open, is to let your sewer hose droop as it exits the connection to the trailer. That creates a p-trap in the sewer hose to block gases from the campground sewer system.
 

Fox

Well-known member
I've occasionally had that smell; my observations are it only happens when my black tank is getting close to full - and I flush - AND the bathroom exhaust vent is on.
For me that indicates it's time to pull the plug, followed by a tank rinse session.
 

Gary521

Well-known member
By leaving the grey tanks open, you are venting the campground sewer system up through your vent pipe. So if some one else is also doing the same thing, you have a nice air flow through the sewer system and guess what you are smelling.
 

Mark-Roberta 051995

Well-known member
Location of smell - Kitchen

Another vote for Studor valve as a possible cause. Kitchen islands for example often have a Studor valve instead of a vent pipe going through the roof. If the valve gets stuck open, odors from the tank get into the interior.

Another thing to do, because you have your gray tank valves open, is to let your sewer hose droop as it exits the connection to the trailer. That creates a p-trap in the sewer hose to block gases from the campground sewer system.


Any photos of this thing as I have the same smell from my island and kitchen only.
 

danemayer

Well-known member
I've attached a picture of a Studor Air Admittance Valve. To test, tape a plastic bag over it and see if the odor goes away.

I've also attached a picture of a HepVo valve which is a replacement for a p-trap that's used where space is limited. They can also fail.
 

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  • HepVo valve.jpg
    HepVo valve.jpg
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  • Studor Air Admittance Valve.jpg
    Studor Air Admittance Valve.jpg
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