Sewer smell when flushing toilet - Need fresh ideas

[MemeNPop]

2 years ago we purchased a brand new 2016 Big Country. From the first fill of the black tanks in this camper we have had a horrible odor when we flush the toilets after they get about 1/3 to 1/2 full. This happens every time we flush but it is definitely worse when its hot outside and gets progressively worse the longer the toilet goes unflushed like over night or if we are gone all day. We always keep the tanks closed until it is time to dump them. We do not have the smell at any other time like it is being pulled in from the air conditioner. We also do not flush the toilets with the air vent fan on.

We have had 3 other campers before this one and have never experienced this problem with any of them and we have never used any chemicals in our black tanks.

With this Camper we have tried multiple brands of Chemicals and Enzymes and The Geo Method.

We have had 3 different shops/service people try to diagnose the problem as well as speaking to heartland directly(who can only tell us it seems to be a venting issue). They always say we just need to add chemicals. The last one told us we need to flush the tank better and charged us a couple of hundred dollars to flush it properly for us resulting in no improvement in the smell at all.

We have flushed it every way possible, with the built in tank flush with a sani-king from the outside, down the toilets with a wand and even by opening the valve and running a hose down the vent pipe into the tank.

We have verified that the vents are not stopped up by anything. And we have also verified with a scope type camera that the vent pipes have not dropped down into the tanks. We did check the grey Studor valves under the sinks by placing plastic bags with rubber bands over them to make sure the smell wasn't coming from them and it is definitely coming out of the toilets when they are flushed.

We installed a 360 siphon on one and a camco cyclone on the other, neither of which helped.

The only time we did not have the smell was when we were installing these new vent toppers. We got called away from the job with the vent caps off of the pipes and couldn't get back to it for a few days. During the 3 days that the caps were off and the pipes were just open we had no smell at all.

Sorry for writing a novel. I have spent countless hours reading online but I am out of ideas.

Any Fresh ideas would be appreciated.

 

[danemayer]

Hi MemeNPop,

Welcome to posting on the Heartland Owners Forum.

Has anyone pulled the toilet and inspected for internal leaks, or checked the seal at the floor?

 

[Garypowell]

Sounds like you need to take the vent caps back off. I don’t have a clue why something that is supposed to have no or very little resistance to air flow would cause this problem.....but it seems to.

Try the vents open again for a few days to verify it was not a fluke and then try some wire mesh over the pipe to keep critters out and play with mesh size to find the optimum cover.

I dont think there should should be any concern over enough water getting in to be a concern.

 

[RoadJunkie]

On my first BH I had to seal the area between the vent tube and the annular space between the ceiling and the roof. The odor permeated down from that point. I used spray insulation foam to seal the area. You may also try THIS gizmo to help ensure the vent is functioning well.

 

[cookie]

I think that based on what you have already tried without success, I think that RoadJunkie has the answer to your problem. Sealing the area around the vent pipes to seal up the area leading to the attic.
I did mine years ago and it solved my problem.
Please do what Len has recommended.

Peace
Dave

 

[MTPockets]

On my first BH I had to seal the area between the vent tube and the annular space between the ceiling and the roof. The odor permeated down from that point. I used spray insulation foam to seal the area. You may also try THIS gizmo to help ensure the vent is functioning well.

We had same problem which was resolved by sealing around the vent pipes. Issue resolved with no reoccurrence after 4 years.

 

[MemeNPop]

Thank you all for your replies. We did make sure to seal all around the vent pipes when we installed the Lippert 360 siphon and the camco cyclone(the gizmo referenced in RoadJunkie's post).

We have not pulled the toilets but have disassembled the basement so that we could inspect under the toilets for leaks and we didn't find any.

I did read a thread in one forum (not sure if it was this one or on another site and I can't find it again) where someone said
that their problem was the vent pipes being too short. They added an extension and that fixed the problem. Does anyone know how high the vents should be above the roof and should the pipe itself sit slightly above or slightly below the cover that sits around it and holds the original cap(not sure what this is called so I hope someone knows what I am describing)

 

[Jim.Allison]

I have had this problem but nowhere near as severe as you have described. I don't know how this relates to you but I don't mix chemicals. Mine is temporary and seems to involve being transported in hot weather. My cure is to drain at first hookup, flow about 5 gallons of fresh water in all tanks add chemical liberally, problem solved. Like you I accumulate then drain.

 

[NYSUPstater]

Had a similar issue w/ our old Creek and we too added the "gizmo" which helped a lot. Sounds like OP has a prob w/ pipe not being high enough to create a "draw" if you will.....sorta like fireplace chimney flue where the top should be higher than peek to aid in draft.

 

[mcsquid86]

I have had this problem but nowhere near as severe as you have described. I don't know how this relates to you but I don't mix chemicals. Mine is temporary and seems to involve being transported in hot weather. My cure is to drain at first hookup, flow about 5 gallons of fresh water in all tanks add chemical liberally, problem solved. Like you I accumulate then drain.

I agree with Jim. I fill up 3-5 gallons of water with a few scoops of ordorlos before we leave on our trips, and I have no odor till we dump. I hope it is a easy fix what ever it may be.