Unbelievable stench from the Black tank

So, we finally get our RV delivered, they forget to detail half the RV and somebody did something to the black tank that has caused such a stench of methane you wouldn't believe it. I climbed up the ladder to the roof and there is no bad smell coming from the black tank vent but inside the RV holy cow the smell is unreal!!

So, I dump the tanks and the black tank take 4 minutes to empty, considering I dropped it off at the dealer with 5 gallons of fresh clean water in the tank this shocks me. I go buy a new hose strictly for flushing the black tank and proceed for the next hour to flush the black tank and even after all of that there is a methane stench inside the coach.

I run the fantastic fan for an hour, still it smells, there is obviously now a venting problem. The roof vent does not come off, it is mounted permanently so I can't check it for blockage. I run water through all the drains in the RV to insure this isn't some kind of backup in the gray water tank.

Tomrrow I will call the dealer first thing in the AM to see what they can do, everytim we run water by flushing the toilet the stench comes through the toilet, I know this has to be a venting problem but can't locate it. What a pain in the arse.

The "methane smell" is more likely coming from the gray tank and gets inside because a P-trap in a drain has gone dry or a vacuum breaker (air admittance device) is leaking air out.  There are vacuum breakers under the sink in galley and bath and they have a rubber "flapper" that con fail. Replacements are available at any home store or plumbing dept - it is a standard plumbing part.

P-traps can dry out if not used. If the rig has a washer or is plumbed for one, that's a likely source.

If there is no odor on the roof from the vent and you get the odor from the toilet, then the vent is either blocked or it has dropped down into the tank.  In either case it's not working and needs to be fixed.

I thought about the gray tank but the smell was coming directly from the toilet. It's obvious the dealer used the bathroom, A LOT. It was near full so I'm thinking something blocked the vent so I back flushed again for an hour after posting the thread last night and then waited until morning. This morning the smell is gone and when you flush it smells like water, I went for a long walk to insure I wasn't just used to the smell and thankfully I think we're good for now.

I also thought that maybe they let somebody from the dealer party in the RV, I've only owned it for 3 weeks so I can't imagine they would do that, the miles didn't change much but that doesn't mean they didn't take it somewhere. I honestly for their sake pray they didn't, but if they did I have no way of proving it. I want to concentrate on getting them to complete the delivery, we keep going back and this time they promised it was finished except for the debris awning. The fact they didn't bother detailing it and then claiming they did makes me question my purchase a bit. Everybody I talk to that has bought from this dealer says they are great, so everybody makes mistakes and it looks like they saved them all for my wife and I.

Anyway, they'll be getting it back tomorrow to make good on their promise, if they don't deliver it will be the last RV I buy from them.

It appears that whatever was blocking the vent has been cleared by the extensive back flushing.  You were lucky

Ned said:

It appears that whatever was blocking the vent has been cleared by the extensive back flushing.  You were lucky

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Agreed!! It was like living in the city dump where they vent off the methane, you could walk around the coach outside and smell it. Disgusting but thank God looks to be resolved.

I was getting a funky sewer smell when I first got my RV, too. Did everything you were supposed to do to clean it out and still a mild smell whenever i drained the blank tank. Just enough to be poohy  I was on the roof one day washing it and checking vents. I found bee hives in both tank vents. The black one was the worst. It had 3 hives in it  I got them cleaned out and haven't had a problem since. Couldn't hurt to check under the vent caps now and again 

in2adventure said:

I was getting a funky sewer smell when I first got my RV, too. Did everything you were supposed to do to clean it out and still a mild smell whenever i drained the blank tank. Just enough to be poohy  I was on the roof one day washing it and checking vents. I found bee hives in both tank vents. The black one was the worst. It had 3 hives in it  I got them cleaned out and haven't had a problem since. Couldn't hurt to check under the vent caps now and again 

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I wanted to, unfortunately mine don't come off.   

KlipschHead281 said:

I wanted to, unfortunately mine don't come off. 

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That makes it kinda tough. Mine were old and UV damaged. I broke them both while trying to pull them off  : I've since replaced them with the kind that slide inside the pipe. So far, no more bees. Why would you build your home in a pooh pipe anyway 

I had odor issues when driving, especially after first dumping both tanks. You might try the 360 Siphon Waste Vent, available at Camping World and other RV supply stores. They replace the OEM caps and:

"Any wind will create a low pressure, pulling out fumes. The design of the unit makes it physically impossible for high pressure or wind to enter the stack. Even when an RV is stationary, a slight wind will enable the 360 Siphon Fume Extractor to pull fumes from any holding tank." (Camping World)

They were easy to install; I simply removed the OEM cap, cut down some of the existing pipe so the 360 Siphon was no higher than the recommendation of the manufacturer and installed using the putty and screws that came as a complete kit. Probably took me longer to get out a hack-saw and tall ladder than to do the actual install.

I wanted to, unfortunately mine don't come off. 

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I think you will find  most will come off with a little work!!!  They may be well caulked and the attachment screws are buried under the caulk. Be prepared to replace those little white plastic cover type though, they will likely be destroyed in the process. I have 3 to do this winter as sun has damaged them to the point of no return...

In any event, I'm glad you got rid of the problem...

in2adventure said:

That makes it kinda tough. Mine were old and UV damaged. I broke them both while trying to pull them off  : I've since replaced them with the kind that slide inside the pipe. So far, no more bees. Why would you build your home in a pooh pipe anyway 

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The actual cap is bolted to the roof, I climbed up again in the daylight and saw that all the bolts were sealed over. So I should be able to remove the sealent and see whats up. Agreed, why build in a vent that vents off stink? 

New weekend, same stench, well, we finally picked it up for good from the dealer, we get it home and the stench is back. I don't get it, now we're at a place with only one dump station, also, somebody left our gray water tank valve open and it dumped into the hose which was still attached and thankfully the end cap is some how holding all that water in the hose.

I also found our front turn signals had been changed around and the parking lamps no longer worked, they were supposed to fix it, said they did fix it, yet when I picked it up, no lights. I fixed it myself, 25 bucks later all is good, however there remains the God awful stench..... again.... 

I had that problem, and we were not using RV appropriate tolet paper.  The solid waste and paper were stuck in the down tube of the toilet.  We learned to use the more expensive stuff and to flush a long time before leaving the restroom.  I hope things get better for you with your RV.  We are having electrical problems and are melting without AC here in Florida.

:-\

smittythebear said:

I had that problem, and we were not using RV appropriate tolet paper.  The solid waste and paper were stuck in the down tube of the toilet.  We learned to use the more expensive stuff and to flush a long time before leaving the restroom.  I hope things get better for you with your RV.  We are having electrical problems and are melting without AC here in Florida.

:-\

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Thankfully our AC is working, sorry to hear about yours having issues, I was having AC issues back on 7/3/10, not fun. We are at the Paul Wolff campground and I had to go buy a second 50ft drinking water hose because the hook up is so far away, the dump station is down so I can't backflush our black tank, so I ran some more fresh water into the tank making it about 3/4 full, added some natural treatment and deodorizer which seems to have helped for now, at least we can't smell it unles we go outside and come back in.

So, tomorrow morning going to head to the dump station and hopefully not get a bunch of people mad at me while I back flush and dump. I may consult another RV dealer to see if the vent is some how clogged up, nothing else makes sense.

smittythebear said:

I had that problem, and we were not using RV appropriate tolet paper.

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You do not need RV toilet paper, that stuff is a complete and total gimmick.  Anything single-ply or safe for septic systems will be safe for RV tanks.  Many of us use the standard Scott TP with no problems.  You still need to use plenty of water and avoid handfuls and handfuls of paper when you can, but paying $1/roll (or whatever that RV stuff costs) is not necessary.

I can attest to the stench as I was there.

OY!!!!!!!!

My much older RV however didn't stink while parked next to his.

/I'll be ribbing him for years on dat one

KlipschHead281 said:

Thankfully our AC is working, sorry to hear about yours having issues, I was having AC issues back on 7/3/10, not fun. We are at the Paul Wolff campground and I had to go buy a second 50ft drinking water hose because the hook up is so far away, the dump station is down so I can't backflush our black tank, so I ran some more fresh water into the tank making it about 3/4 full, added some natural treatment and deodorizer which seems to have helped for now, at least we can't smell it unles we go outside and come back in.

So, tomorrow morning going to head to the dump station and hopefully not get a bunch of people mad at me while I back flush and dump. I may consult another RV dealer to see if the vent is some how clogged up, nothing else makes sense.

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Luckily, no one was waiting while you back flushed.

Enjoyed draining both RV's with you.........

/not

scottydl said:

Many of us use the standard Scott TP with no problems. 

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What ever brand you buy, it will always be Scott's TP.

Marc L said:

What ever brand you buy, it will always be Scott's TP.

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Well... yeah    But my wife uses more of it, so maybe it's hers?!