black tank roof vent

[lowroller]

Can you run water down the roof vent to clear anything that may be blocking the ventilation..?

[bigb]

Originally Posted by lowroller

Can you run water down the roof vent to clear anything that may be blocking the ventilation..?

If the pipe has no leaks or breaks in it, and it should not unless it got damaged or was poorly installed, yes. Are you getting odors?

[wyocamper]

You could also use a long dowel rod or similar, or a tape measure. I was able to shine a light down mine and see the bottom of the tank.

[lowroller]

Yes, Hoping cleaning the pipe will help. Thanks for your reply.

[lowroller]

Thanks. I have a chimney sweeping set-up. I think I'll try just the rods from the set.

[be happy]

While you have the old cap off you might want to think about replacing it. I had an odder problem and replaced the cap with one that spins with wind direction.
Camco Cyclone Rotating Sewer Plumbing Vent

[Morich]

If this is a motorhome, you can also findthe parts here:
https://catalog3d.winnebagoind.com/menu/Parts.htm

Seeing how things are put together can help spot suspect points?

[bigb]

A few different issues can cause odors, if your bath sink drains into the black tank there is often a Studor type valve under the sink, these can wear out and leak. Another issue is some toilets leak air through the flush valve or through the assembly seam at the bowl, like the Aqua Magic V. No 100% cure for that as I found out with my Aqua Magic V which I even replaced with a brand new one, just poor design. There was another model which I believe is a Dometic 300 that has a poor design and traps waste in the assembly, If I recall there was even a recall on some of them. Pressure in the tank caused by air being forced down the factory vent while moving exacerbates the situation and we would only smell it when driving , but in my case a Lipper Siphon Vent on the roof stopped it.
Also don't rule out gray, it can smell bad too. I knew mine was black though, definite difference in the type of odor.

[Mtn Charlie]

Empty P-traps can also cause tank fumes inside the RV. We never used our clothes washer, so I removed the washer drain hose from the drain pipe and capped it.