Sewer vent smell - need advice

[mrkoje]

I am having an issue with sewer odors in my trailer. They seem the strongest around the toilet. I've done some research on here and I think I've narrowed it down to the rooftop vent for the black tank.

Can someone please give me some advice on how I should or could repair this vent. The pictures below are for comparison between the rooftop vent for the gray tank (which looks normal to me) and the broken or incorrectly installed rooftop vent for the black tank.

Here is a picture of the gray tank rooftop vent:

Gray tank (normal looking vent)

Here is a picture of the problem black tank vent. It may be hard to see from the picture but the black hose/pipe that should be above the roofline is approximately 3" below the roofline. It also seems that the vent cover is broken because there is a larger hole here.

Black tank vent (broken or not installed correctly)

Any advice would be appreciated on the repair. I think I will be replacing the cover with one of those 360 degree siphon types that I've read about.

I haven't taken the entire vent cover assembly out yet because of the weather today. I don't have a replacement yet and I didn't want to leave it off over the night.

[mrkoje]

I've had the black tank pretty darn close to full and nothing out of the ordinary. I'm not sure I'm 100% on what you mean by a burp. I'm taking it as gases escaping from the toilet opening when flushing. When I flush it does get smelly but it doesn't make an audible sound!

[Old-Biscuit]

If black tank vent line slipped down into tank....toilet would 'burp' at a tank level less than Full.

If black tank vent line was just installed short at roof linedue to 'craftsmanship' :S then you should be able to fill black tank completely full and not have toilet 'burp'

[westend]

Good place for a tape measure. Measure from floor to ceiling, add ceiling -> roof dimension, add 3/4" for flooring. The vent should be in the tank at least two inches. You don't want the vent against the bottom of the tank, either.

[mrkoje]

ScottG wrote:
Your pic makes me wonder if the black tank vent has somehow slid down into the tank.

I can see the end of the pipe that makes it way into the tank. It's about 3-4" below the roofline. Not sure if I should attempt at moving it and risk pulling it out of the tank (In case they cut the pipe short at the factory and said screw it) or do I just make an extension with some 1.5" flex tube or PVC etc..

[ScottG]

Your pic makes me wonder if the black tank vent has somehow slid down into the tank.

[mrkoje]

That's what I'm going to do. Question is did the original black pipe start out looking the gray tank pipe and fall down or was it never installed correctly. Can the "pipe" fall down?

I would presume that it was installed correctly and it got knocked out of place and then wedged itself under the roof. I want to be cautious moving or tugging on it though because I would hate to pull it right out of the black tank. I think I would have a bigger issue then I'm dealing with now if that happened!

[Home_Skillet]

You will need to extend the existing pipe up above the roof.
Maybe find a pvc pipe that will fit snug into the black pipe.