Strong urine smell in pantry cabinets

[gerri819]

We have a 2021 imagine 22MLE that has developed a strong urine smell in the pantry cabinets and 3 drawers that are underneath. This sits beside the bathroom wall. We emptied/flushed the black tank now twice and treated with dawn and borax and run until clear. We maybe let the tank get 2/3 full before emptying but this is routine on a long trip. The bathroom does not have the smell and the toilet I can stick my nose down when flushing but no smell. It is just in the pantry and 3 drawers. We removed the bottom drawer and looked for any possible rodent. Nothing. The vent on the roof seems intact and no smell from that. I did check the air things caps under the sink in bathroom and kitchen and both were loose so just hand tightened them. So not sure if or where the black tank vent is but I bet it is in the wall between the bathroom and pantry. Mobile tech was called but no response as to a time to come out. Besides flushing the black tank
again, any suggestions.

[ThePowells]

gerri819 Welcome to the family and the forum! In many experiences, gray tank odor is worse than black tank. I don't have any knowledge of your floorplan or where your vents are, but on many of them they tie in together in the wall in order to have a single roof protrusion.

[JeffC]

I'd look for mouse droppings and then take a look at the underbelly for holes. We had the same problem until I plugged and uncovered generator hole in the chloroplast. We didn't have a generator but the factory in its wisdom had drilled the hole anyway.

[howson]

We have a 2021 imagine 22MLE that has developed a strong urine smell in the pantry cabinets and 3 drawers that are underneath. This sits beside the bathroom wall. We emptied/flushed the black tank now twice and treated with dawn and borax and run until clear. We maybe let the tank get 2/3 full before emptying but this is routine on a long trip. The bathroom does not have the smell and the toilet I can stick my nose down when flushing but no smell. It is just in the pantry and 3 drawers. We removed the bottom drawer and looked for any possible rodent. Nothing. The vent on the roof seems intact and no smell from that. I did check the air things caps under the sink in bathroom and kitchen and both were loose so just hand tightened them. So not sure if or where the black tank vent is but I bet it is in the wall between the bathroom and pantry. Mobile tech was called but no response as to a time to come out. Besides flushing the black tank
again, any suggestions.

You've done a good job troubleshooting--you've hit all the obvious. And you're right about the black tank vent. It's in the wall between the bathroom and pantry.

My guess is either one of the vents (there may be two, or at least that's what the drawings suggest) has come loose or the toilet is not completely seated to the black tank. When the tank reached a high enough level of fluid some leaked out.

Why is the smell getting into the pantry? The power distribution panel is at the base of the pantry. There's a lot of wires that come up through the floor behind it and typically GD does not seal around the wires--plenty of opportunity for air that is underneath the camper (below the floor but above the coroplast) to make it's way into the living space.

What you could do to try and verify is remove a few screws from the coroplast (that's the black sheeting underneath the camper) along the frame edge under the pantry area. Careful--there may be liquid sitting on the coroplast so don't take a "shower" by being right underneath! Once you have a bit of access stick your nose and flashlight up there. If residue from an overflow is the issue it should be obvious. Finding the exact source of the overflow (and eliminating the odor) will be a job.

Howard

P.S. Please report back once resolved!

[gerri819]

Howard, do you know where the black vents are?

[howson]

Howard, do you know where the black vents are?

The black tank vent (singular) is (I think) literally a pipe that goes from the top of the black tank to the roof. There's a small cap over the pipe in the roof.

My 315RLTS has three vents in the roof -- below is what two of them look like on top of my 315RLTS. (The three are for the washer gray tank, shower gray, and the rear-most is for the black tank.)

[gerri819]

Howard,
does the black tank vent ever get blocked? We have a mobile tech coming tomorrow and I think I have heard of people flushing it from the roof?
the smell has lessened some but is still there and is greater as the heat of the day progresses.

[Jlawles2]

gerri819 It is possible for flying insects to build nest in the vents. Be careful when exploring the vent as flying insects may catch you off guard and potentially lead to falling off the roof.

[howson]

Howard,
does the black tank vent ever get blocked? We have a mobile tech coming tomorrow and I think I have heard of people flushing it from the roof?
the smell has lessened some but is still there and is greater as the heat of the day progresses.

That's a possibility, but if the vent was truly blocked the potty wouldn't flush very well. I've never personally seen it or experimented by simulating a blocked vent, but if the air in the black tank has nowhere to go (when the toilet is flushed) there should be what some have described as "burping" as the air is forced back up past the contents making it's way into the tank.

I'm still leaning towards a vent pipe that is not 100% securely connected or a leak near the top of the black tank. Your mobile tech should be able to quickly determine if there's residue on the coroplast causing the smell.

Please let the forum know what your tech finds! It will be quite OK if I'm wrong...trying to troubleshoot via a keyboard is not the easiest thing to do.

[Tigger1]

gerri819

Not sure this is your issue but on our 2020 22MLE we have had a struggle with strong black tank odor. It has taken us awhile to figure it out.

First, I went on the roof and removed the black tank vent cover and put a garden hose partially down to see if it was clogged. My DW stayed in the trailer in the bathroom and could hear the water trickle down. This suggested a partial blocking at the bottom of the vent where it goes inside the black tank. I also took note that the vent cover had very little space for air to escape. So I ordered and replaced it with a white 360 Siphon RV tank cap as you can see in the photo.

We were still unsure why the partial blockage was occurring. After more research we came to realize that the blank tank vent is located in the wall behind the toilet abutting the pantry, as noted by howson above. In and of itself that is not an issue. However, our driveway is slanted downward and I have always, even on our previous trailers, kept the trailer nose down to take pressure off of the electric jack.

With our 22MLE this meant that whatever paper not completely cleared out from our previous camping trip was laying up against the vent pipe since the nose of the trailer was down. In the heat of the summer it dried out enough, even though we always keep a few gallons of water in it, to cause a partial clog resulting in the strong odor.

Once we came to this awareness we started parking the trailer more level. Between that and the 360 Siphon we have figured it out. We do use a combination of Dawn and Calgon along with a chemical packet. And I should add that we do a more thorough job of cleaning the blank tank before leaving the campground now.

[gerri819]

Tigger1 thanks for the input. The only place we smell it is in the pantry and drawers. Not in bathroom or even in the toilet. Very stumping for sure.

[gerri819]

Howard
the mobile tech came after we started having dripping from underbelly that was urine. He dropped the underbelly and the black tank and the “boot” that goes apparently from toilet to tank was cracked and then when the tank got full it leaked out. Does this make sense? He is ordering another that should be in Monday. Wonder if it was cracked all along and this was the first time the take got too full or it was something we did to crack it ??? Also I was surprised and no insulation etc in underbelly but made an easier cleanup.

[Country Campers]

gerri819

There is no insulation in the underbelly of an Imagine, just a foil sheet. The "boot" is just a large rubber grommet that the toilet pipe sits into, I am not even sure if it is clamped or not. It is possible that it is cracked but not from anything you would have done. If you could possibly get some pictures of this failure that would be great, we could pass it on to Grand Design, this is not something that I have heard of. I would also want to make sure that the tank is held in place and not sliding around which could cause damage to the pipe or boot. Please keep us updated.

Brian

[gerri819]

[gerri819]

This is what the tech found. The boot was bent like picture above and the pipe was sitting so that when tank would get full the fluids would leak out. Repair all done and not more smells. !!! He stated the tank was secure but not sure how that happened.