Black water smell on second trip

[Wolfpacker76]

So, the first trip out in our 2012 Surveyor SP 260 went great, however after having the camper home for a few weeks the black water tank began to cause a horrible odor in the bathroom. If you flushed the toilet, it would take a few seconds and the odor came up the toilet and was unbearable.

I had black water flushed the tank for 20 minutes before we came home last time. No matter how long or how much I flush them this past weekend the odor wouldn't go away. I've heard of the Eco treatment and what not, but first i crawled up on my roof and found the vent cover screwed into the small vent tube, actually blocking off the small tube. Is that a problem? I would think that would prevent fresh air ventilation. Maybe something the dealer missed on the PDI? The grey water vent was not like this, meaning the lid was screws into the small vent hole, thus the grey water does not stink.

Am I on to something here or is there another cause I should be looking for? I had used the dark blue chem solution Forest River provided with the camper in the black tank along with a few gallons of water before it sat for a month.

Finally, according to the photos, should the hole in the cap be directly above the small vent tube, or should the cap be turned to prevent rain water from entering it? Thanks in advance, and forgive me for any typos, posted this from my phone.

[Herk7769]

The "small vent tube" is a plastic stand off to receive the screw that holds the cap on. Sounds like they just jammed the cap on blocking it off. The cap is there to keep rain water from entering the vent.

Oh, and if that cap was jammed on the vent pipe so as no air could come in; THAT is why your tank stank.

[Wolfpacker76]

Originally Posted by herk7769

The "small vent tube" is a plastic stand off to receive the screw that holds the cap on. Sounds like they just jammed the cap on blocking it off. The cap is there to keep rain water from entering the vent.

Oh, and if that cap was jammed on the vent pipe so as no air could come in; THAT is why your tank stank.

So, the screw was NOT supposed to be screwed into the small vent hole? Just making sure I understand correctly. Does the small tube allow air to enter black tank and the larger hole allow air to vent out? I took the screw out, the cap is held on by plastic clips anyway.

[OldCoot]

Originally Posted by herk7769

The "small vent tube" is a plastic stand off to receive the screw that holds the cap on. Sounds like they just jammed the cap on blocking it off. The cap is there to keep rain water from entering the vent.

Oh, and if that cap was jammed on the vent pipe so as no air could come in; THAT is why your tank stank.

Is the vent not double acting by letting air out during flushing and to let air in when dumping?

[Herk7769]

Originally Posted by Wolfpacker76

So, the screw was NOT supposed to be screwed into the small vent hole? Just making sure I understand correctly. Does the small tube allow air to enter black tank and the larger hole allow air to vent out? I took the screw out, the cap is held on by plastic clips anyway.

No sir. The "vent hole" business was your quote. It is just a place to hold the screw that holds the cap on. Air does not go in or out of that small hole. The BIG hole is where the "venting" takes place. I would make sure wasps have not built a nest in the vent pipe though.

Also I am assuming you are talking about black tank odors.
You do realize that gray tanks can smell bad too.

Make sure there is water in the toilet bowl at all times.
It is needed to make an airtight seal.

I had an odor once in the camper that took me a week to track down. A soapy dish cloth was left under the kitchen sink (yea, I know... my fault again). Man did THAT smell bad after being in a closed camper for a month.

[youroo]

I see (2) problems, 1 vert.black vent pipe is too short and 1 vert pipe is too long. The proper length is stated on the vent cap,most of the time. Youroo!!

[Wolfpacker76]

Oh no, definitely black tank. Smell was horrendous when flushing toilet. Shined a flash light down big vent hole, didn't see any blockage. A little curious if some solid waste didn't get cleaned out during tank flush after last trip. Like I said, flushed tank with black water flush hookup a few times during our trip this weekend and smell didn't subside much.

Keep hearing about bacteria forming in black tank to keep odor down, maybe camper is too new for this yet? Not sure, maybe I'm reading too many different threads about black tank odors, making my head spin.

[Wolfpacker76]

Originally Posted by youroo

I see (2) problems, 1 vert.black vent pipe is too short and 1 vert pipe is too long. The proper length is stated on the vent cap,most of the time. Youroo!!

Soooo, how do I fix this, since pipe is not adjustable? Take back to dealer?

[youroo]

I have seen many vent pipes instaled wrong. Your (Short pipe) could be setting on the bottom of the tank,how,they let it fall before the glue set up,they cut the pipe too long,ect. They also cut the pipe too short where it will not even go thru the ROOF,thus water runs in the (Boot) area. I have not seen it (ALL) but I have seen a (LOT)! Yes measure the pipes if they are not (2-21/2) long above the flange (Like stated on your CAPS) take it back to the dealer. Youroo!!

[jimh]

it's hard for me to tell if u r vented or not. there should be a small space between the cap and pipe. sense the space is under the cap, u may not be able to see it. the screw just insures that the cap doesn't fly off. what i'm looking at appears normal...but i'm not there.

do u put tank treatment in the tank while in use? r u containing ur black water until u r ready to leave or it fills which ever comes first? the answer to both of these questions should be yes.

[Herk7769]

Originally Posted by Wolfpacker76

Keep hearing about bacteria forming in black tank to keep odor down, maybe camper is too new for this yet? Not sure, maybe I'm reading too many different threads about black tank odors, making my head spin.

Time for one or two 72 hour RV-Digest-It treatments and flushes.
RV-Digest-It.com - RV-Digest-It

[youroo]

With a 20 min.rinse and the smell is still horridness no Magic brew is going to fix this. You still have POO in the tank. What did the Clear elbow flow look like? Try someone depressing the toilet valve and keep it open before you open the Dump valve,this will bypass the roof vent. There could be a plastic disc covering the discharge passage also,from where they drill the holes in the tanks. Youroo!!

[Wolfpacker76]

Originally Posted by youroo

With a 20 min.rinse and the smell is still horridness no Magic brew is going to fix this. You still have POO in the tank. What did the Clear elbow flow look like? Try someone depressing the toilet valve and keep it open before you open the Dump valve,this will bypass the roof vent. There could be a plastic disc covering the discharge passage also,from where they drill the holes in the tanks. Youroo!!

The elbow had clear water when I flushed it a month ago. When I dumped the month old water (with treatment) when we first got to the site last Friday, the water was a pea green, with some dark colored flakes (sorry to be so graphic). I may have dumped the tank too often when we camped a month ago, but the heat was pushing 100 for a few days and the odor was starting to form.

The elbow was clear when I flushed this morning before I left the site. If the odor returns, what next?

[OldCoot]

Originally Posted by Wolfpacker76

The elbow had clear water when I flushed it a month ago. When I dumped the month old water (with treatment) when we first got to the site last Friday, the water was a pea green, with some dark colored flakes (sorry to be so graphic). I may have dumped the tank too often when we camped a month ago, but the heat was pushing 100 for a few days and the odor was starting to form.

The elbow was clear when I flushed this morning before I left the site. If the odor returns, what next?

I would try sticking your black tank hose down the vent with full pressure and have someone open the black tank valve and see if you get a good flow of water. That will show whether the vent pipe is open. I would also stick a tape down the tank till it hit the bottom and then try to snag the end of the pipe and see what the difference is. Pipe may be too close to the bottom and if that's the case, a trip to the dealer is warranted. Just a guess, but I would think you should have from 5"-6" difference at a minimum.

[youroo]

I bet you are on a seasonal site,if so are the tanks off camber to the dump valve? Trailers going down the road get a lot more action in the tanks. Youroo!!

[Wolfpacker76]

I'll try the tape measure trick and get back to you. No seasonal site, camper travels everywhere we camp, we store it at our house.

[Wolfpacker76]

Ok, I measured from the bottom of the vent tube (bottomed out on bottom of black tank), and then pulled up to where the tape measure would catch the bottom of the vent tube. I have exactly 5 inches of clearance from bottom of tank from end of vent tube. I guess that is enough?

Here is where I think I may have messed up, thanks to everyone's great input. 1) I haven't been leaving any water in the bowl to prevent odor from coming around the flapper seal. 2) I have been emptying my black water tank much too often, like once a day, not even 1/3 full. I makes sense that this is not enough time for the solid waste to break down. Most likely some poo may have been stuck in black water tank and didn't flush.

I'll give it a week or so and see if the odor returns like before. Check on this thread sometime, in case I have some more issues. Thanks FR Forum, you guys are a big help.

~Billy

[Herk7769]

Originally Posted by Wolfpacker76

Ok, I measured from the bottom of the vent tube (bottomed out on bottom of black tank), and then pulled up to where the tape measure would catch the bottom of the vent tube. I have exactly 5 inches of clearance from bottom of tank from end of vent tube. I guess that is enough?

Here is where I think I may have messed up, thanks to everyone's great input. 1) I haven't been leaving any water in the bowl to prevent odor from coming around the flapper seal. 2) I have been emptying my black water tank much too often, like once a day, not even 1/3 full. I makes sense that this is not enough time for the solid waste to break down. Most likely some poo may have been stuck in black water tank and didn't flush.

I'll give it a week or so and see if the odor returns like before. Check on this thread sometime, in case I have some more issues. Thanks FR Forum, you guys are a big help.

~Billy

Billy, you are very correct. By trying to dump every day, solids are piling up right under the drop tube and there is not enough water flow to push it out.

Not to be too harsh, but NEVER dump the black tank with less than 2/3 full light on (about 1/2 tank of water). If you need to dump sooner (like you are leaving to travel home that day and you need to dump empty); hold the flush lever down until the 2/3 light comes on. Then turbo-flush with a clear elbow until the water runs clear. It will but it will take about 15-20 minutes of flushing. (longer since you have a lot of gunk in your tank.)

Always leave water on the seal; as well. It is what keep the odors out as the goo disintegrates. Oh, did I mention RV-Digest-It? You need to be doing that right now until your tanks are clean.

[showtime0022]

Might try dumping some ice before towing. That way when in tow ice helps clean sides, also add chemicals a week or two before using. That why enzyme has time to grow and work.

[TexasBBQ]

Originally Posted by Wolfpacker76

Soooo, how do I fix this, since pipe is not adjustable? Take back to dealer?

Use an oscillating saw to cut it down a little.

Yes, the screw is used to secure the cap to the base.