What's That Smell

[Hunter11]

And the saga continues......So we are sitting here in the Landmark watching TV last night when a strange smell hits us both. We look at each other and point fingers but soon realize the sewer smell we are blaming each other for is coming through the AC vents. Since we have not had anything go wrong in the last few days our joy turned to disappointment again. Looks like an another call to Heartland early Monday morning. This is really getting old......I mean getting OLD!

The smell seems to be mainly coming from the main AC unit vents but there was some coming from the bedroom AC vents. I had just drained and flushed the black tank two days ago so it was not full. I had to go out and drain the tank and flush it again in the dark last night to try and get the smell to stop which it did for the time being. I did notice when I walked outside to drain the tank in the dark (10:00 PM) that I could smell sewer. Nothing has changed in our normal black tank routine. I saw no leaks under the trailer so my thought at this point is we have a leak in the black tank vent pipe in the "attic" area causing the smell to get sucked into the return air and blown out the AC vents. At this point I am really at a loss on this unit.

 

[jbeletti]

Sorry to hear about this issue you're having. A suggestion on how to check this yourself to confirm your theory...

Go up on the roof with a phillips screwdriver and channel lock type pliers. There will be several small round vent caps on the roof. Try to determine which may be for the black tank. The vent caps I've seen before have a screw that hold the cap onto the vent base. Usually, there's a dab of sealant over that screw. Pry that sealant out and remove the screw, then pop the cap off.

What you'll be looking for is a vent where the PVC vent pipe has slipped down into the roof and is no longer connected into the vent base.

The fix is likely more difficult than finding the vent pipe that has slipped, though maybe, temporarily, you can grab the pipe edge with a pair of channel locks and pull it back up.

I believe the permanent fix is done from under the coach where the pipe goes into the tank.

 

[JanAndBill]

Not sure if this could be the same as your problem, but our BH has an auto vent (not vented to outside) on the bathroom sink. Not sure if the kitchen does or not, haven't ever looked. Sometimes if we leave the grey tank valves open, we will get sewer gas back into the trailer. The solution is to just dump the tanks then close the valves.

 

[Majestic]

We have different models, maybe similar plumbing. Notice the angle of the fittings.

This 1-1/2" vent pipe was slightly short. When it dropped down a 1/2" it lets fume into the AC cavity. We cut the connection out, installed an extra 1-1/2 splice to push the vent pipe all the way through the roof.

If this is your problem, we found it easier to wiggle the vent line around until it found the proper opening in the vent cap and wedged a 2x4 under it until we could get home and fixed. I know you are already home.

 

[Majestic]

Second pic didn't load

 

[tboy]

I had the same problem with my Key Largo, it was a easy fix for me . I took the caps off all the sewer vents on the roof and the vent that comes up above the washer and dryer had no caulking around the pvc were it goes through the roof, there was about a quarter inch gap around the pipe. I caulked around the pipe and never had the problem again, the odor was being pulled back into the ceiling when the air was on or when the max air fans were on.

 

[azbigfoot]

I had the same smell coming from my a/c vents. This is a common problem because the vent pipes do not fully extend out of the roof caps. I checked all three of my roof vents and all were below the cap level. This lets the sewer gas back into the roof to be picked up by the A/C units. I guess there could be a couple of solutions

1) Caulking where the vent pipe comes through the roof. To do a good job it seems like the vents (not just caps) would need to be removed, caulk around the pipe, and the reinstall the vents (with new dicor). It would be good to have someone post pictures of this process.

2) If pipes are long enough figure why they have slipped down and prop them up from below so they extend fully through the vent.

3) Splice in an extension to the vent pipe.

As a temporary solution I removed the cap like Jim suggested and then used some heavy foil tape from the inside of the sewer vent pipe to the outside of the sewer vent cover. This prevents the the gases from leaking back down into the roof and has stopped the problem until I get a chance to fix it properly.

Personally I think the vent pipes are installed too short at the factory because this problem seems to be too common on the forum.

 

[Hunter11]

I am headed up on the roof shortly with tools and caulk. Seems like every weekend since we got this trailer home I spend working on it.

 

[Tallyrver]

The DW was complaining about a bad smell the last time we were out, I figured it was the baked beans ...i just went in the rv and the smell is still there. Time to go up on the roof with some tools and see what's up.

Wayne

 

[Hunter11]

I just got off the roof and here are my findings. I pulled all four vent caps and they all had gaps around the roof vent where the pipes were cut off a little short. The W/D vent being the worse of the four. I caulked around all of the pipes where they come through and put the caps back on. I guess we will see what happens. I know they are in a hurry building these things but they could allow a little more pipe to come through after they cut it off.

I also removed the back wall of the pass thru storage area and checked all the drain pipes. They all seemed fine and no odors in that area.

 

[FordMan1966]

Well we have an odor in our 2013 Grand Canyon sometimes if I am flushing the black tank and the kitchen sink drain is open. The smell comes thru the sink drain. We pointed fingers as well the first time and even blamed our 2 Dachshunds. You also mentioned you have worked on it a lot. Well I just got use to it. It has taken almost 2 years to get the bugs worked out of ours.

 

[Hunter11]

You also mentioned you have worked on it a lot. Well I just got use to it. It has taken almost 2 years to get the bugs worked out of ours.

FordMan1966, that is not what I want to here right now with the amount of issues we have had in less than a month.

 

[910bro]

Hunter 11,
We are having the same odor issue in our '14 Monterey. I did pull the vent caps and yes, the vent stacks are short. Has the caulking done the trick for you ? I'll do the same, it can't hurt anything.

 

[Hunter11]

910bro, as of right now we have not had the sewer smell coming through the AC vents since I did all the caulking on the vent pipes Saturday (knocking on wood as I type). I am hoping this issue is resolved but want to wait a while before I declare it so. I would be interested in how it works out for you.