Black tank vent 2021 Fuzion

[Mike Honcho]

On our 2021 Fuzion 427 the toilet in the master always has an odor when flushing. Has done this since day 1. We treat with campa chem just like old unit. Back toilet does not have this issue.

So we finally got in for a list of warranty items. On this issue they say I have to clean tank more often and treat contents better. They say the vent is connected correctly. Maybe so but is it connected correctly is my question. Maybe its attached but hole not cut in? I did a large building controls project where we had zero airflow on a whole floor. Tin knockers attached all branch ducts to main without ever cutting the hole in the duct!

So have searched all over for pictures or video's of how this connection is made so I can try to fix. But I come up with nothing. I don't know if connection is a fitting that vent pipe gets glued to and requires a hole cut beneath it or if it's a fitting that vent pipe goes down through and into the tank, possibly in too far. It definitely acts like a blocked vent. Also the tank empties fine.

I'm stumped and the dealer will not investigate further.

[NH_Bulldog]

The fitting on top of the black tank is pre-installed and the pipe fits down into it from above. The easiest way to check is to get up on the roof, pull the vent cap off and shine a light down the pipe and into the tank.

Another couple of thoughts; have you checked the AAV under the sink for proper seal and operation? Depending on floorplan configuration, some sinks and showers drain into the black tank either on purpose or by accident. Another thing to check is the toilet seal on the floor.

[Mike Honcho]

Thanks for quick response.

I have a separate grey tank forward for sink and shower. Kitchen and Half bath share second gray tank. Separate Black tank for 1/2 bath so the black forward is only toilet, vent, and drain.

Is it possible that the vent pipe extends too far down (as in not adjusted properly before securing) into tank? If so it would allow drain but once level is high enough it would be blocked.

[Mike Honcho]

Update on research. Watched a video on black tank replacement to get a look at vent connection. It is basically a large rubber grommet that inserts into hole in tank providing a rubber "boot" that the vent pipe slides through. So at this point it seems the pipe is down too far in the tank. Probably on the bottom if it was never adjusted before cutting excess at the roof.

Looks like a fix I could do but first I'll have them check this when I go back for rest of warranty work.

[firestation12]

Originally Posted by Mike Honcho

On our 2021 Fuzion 427 the toilet in the master always has an odor when flushing. Has done this since day 1. We treat with campa chem just like old unit. Back toilet does not have this issue.

So we finally got in for a list of warranty items. On this issue they say I have to clean tank more often and treat contents better. They say the vent is connected correctly. Maybe so but is it connected correctly is my question. Maybe its attached but hole not cut in? I did a large building controls project where we had zero airflow on a whole floor. Tin knockers attached all branch ducts to main without ever cutting the hole in the duct!

So have searched all over for pictures or video's of how this connection is made so I can try to fix. But I come up with nothing. I don't know if connection is a fitting that vent pipe gets glued to and requires a hole cut beneath it or if it's a fitting that vent pipe goes down through and into the tank, possibly in too far. It definitely acts like a blocked vent. Also the tank empties fine.

I'm stumped and the dealer will not investigate further.

If you have a powered ceiling vent running with all windows and doors closed, it is possible to create a negative pressure inside the camper, which will pull odors from the black tank each time the flush lever is operated. An open window on the lee side of the camper may produce the same effect. There are aftermarket roof vent caps that create a venturi effect to enhance vent performance.

[notanlines]

Without going into complicated, scientific methods to check on your black tank, simply climb on the roof with 5 gallons of water and pour it straight down the vent stack. If it flows into the tank and out your drain towards the sewer it is the very best that the manufacturer could do. It is simply no more complicated than that. The poster who brought up the negative pressure idea was probably the one that has The solution to your problem.

[Mike Honcho]

Well, found the smoking gun I think. After several exercises with shop vac on toilet end and on the roof I used a section of metal snake to prove out I could get all the way down into the tank. Then put a back bend on the end so I could feel tension when the end of snake went into vent pipe. Pulled up and it was about 11 inches, so pipe was not on bottom of tank like I was thinking.

So being finished I yanked out the snake. Well on the way up it snagged a white solid piece of what came out of a hole saw cutout. So all that getting nowhere and then just pure luck probably fixing it pulling the snake out. Using camper for 3 day trip this weekend and will post back if it's fixed or not. I'm betting it is.

[Scttw]

Originally Posted by Mike Honcho

Well, found the smoking gun I think. After several exercises with shop vac on toilet end and on the roof I used a section of metal snake to prove out I could get all the way down into the tank. Then put a back bend on the end so I could feel tension when the end of snake went into vent pipe. Pulled up and it was about 11 inches, so pipe was not on bottom of tank like I was thinking.

So being finished I yanked out the snake. Well on the way up it snagged a white solid piece of what came out of a hole saw cutout. So all that getting nowhere and then just pure luck probably fixing it pulling the snake out. Using camper for 3 day trip this weekend and will post back if it's fixed or not. I'm betting it is.

Wow, what a stroke of luck, update right there!

[Mike Honcho]

That was it. Problem solved.

[ASCTLC]

That's a stroke of luck alright.

My vent pipe wasn't even attached when I got mine. it was "Used - Like New" when we bought it as most stickers were still on it. Obviously out of warranty but not too much a biggie for me since I can tackle most any repair with a little determination.

But when I pulled the thin wooden bulkhead that separated the Pass Thru from the belly I saw the black tank vent was run in the wall but wasn't attached to the rubber boot connecting to the tank. That would have been one chitty mess had the black tank been used before I saw it. Luck was on my side that day too.