[Jim/Chris]

Chip, flushing the tanks may help, but we’ve found that when it gets hot outside and those microbes down there shift into overdrive, the best way to prevent any hint of odor is a little shot of tank anti-stink. We use the green stuff that comes in gallon jugs from Walmart. It does not take much to do the trick. I usually put a shot in the gray tank, too.

[Corey]

we’ll give it a try.

[Chip & Pam]

Open the bathroom and kitchen cabinets under the sinks. Does the smell get worse? The vacuum vents under each. At the age of our coaches, they may need to be replaced.

Yes, the water connection in the sewer bay is a black tank flush. I never use chemicals anymore. An expert in the field said to let the bacteria work. I dump the black first. Once empty, I leave the black valve open then cycle the gray open for less than a minute, let it drain and repeat 4 or 5 times. I then close the black tank and finish draining the gray.

[Dick]

Gil

the vents under the sinks are ok. We tend to get the odor from the potty even when it holds water at normal level.

I will use your method when dumping the gray. Getting some gray up into the black to brak up waste is a great idea. As for chemicals, would the green stuff Byran mentioned have a positive or negative impact? I would think it would help when I flush the tank as we are unsure of when the last flush was. The goal is to clean up the tank, eliminate the odor but do no harm to the plumbing. We have banned any bleach or chlorine products due to post where it mentions PB fittings can fail from them.

Thanks for all the great advice.

Chip

[Archived]

My 1997 Royale did that it was the vent cap on roof ,it was not sealed good where the vent cap went over tube on roof I replaced with a cyclone vent it quit if you put something in tank use Happy Camper ,www.happycampersworld .com ,, no smell when you empty just do it once put done sink shower drains and in toilet it will take the smell right away, it’s a powder will not hurt any thing better than all the other stuff out there

[Liam]

Who would be the industry expert Gil and what documentation to you have to support his claim?

[Archived]

If there are sewer odors in the coach check traps and drains first. If they are not filled with water that drain becomes an open path to the holding tank. The obvious ones are the sink traps, but some coaches have icemaker drains and washing machine drains. If those appliances are not used the drains dry up and that could be the source of the odor.

But if the traps are full, then as Gil suggests check the air admittance valves. They are not looked upon with favor by the plumbing codes, but are necessary when a vent for a drain is required, but there is no way to connect to the building roof vent system. In our coaches the air admittence valves are sometimes used when the converter cannot plumb into the roof vent system such as under a kitchen sink. They do fail, but rarely do they fail open because a spring holds them shut. Usually they fail to open and the sink drains slowly.

If the traps are full, the air admittance valves are closed then start looking at the roof vent to make sure it is not blocked. But hope that the odor problem is not a leaky holding tank because that is the only think left to cause odors that I can think of. If you have an odor when you open the bay door you might have that problem.

[Archived]

Don’t try to fix the stink problem by scenting the holding tanks. Regardless of your decision of what you put in your tanks, you need to find the source of the odor. You’ve eliminated the below the sink cabinet vents, which by the way are perfectly acceptable by any building code that allows a sink to be installed in an island.

You have probably ran water in every appliance so that the pee traps have water in them. One thing to look at related to the pee traps is when does the stink occur. If it only occurs when the gray or black water tanks are drained, it could be restriction on the roof vents. Restriction here. although probably not common, would drain the pee traps when the gray water tank is drained.

The rood vent, as mentioned could be the source of the stink. The one roof vent is not that far from the toilet room’s ceiling vent. It’s possible for a breeze in the who direction to push stink from the tank vent to the toilet room vent. If this is the case, the directional stink vent attachment mentioned earleir may be beneficial.

[Archived]

Tom,

I’m not sure why you care, maybe you’re one that uses the chemicals. The expert used to frequent iRV2.com long ago, may still. I don’t remember her name. I think it was Peggie. She had reams of data. None on which I cared to keep as I didn’t need any of the source data that I really didn’t fully understand. I’m not going to debate her expertise given I don’t really care. You can do what you feel is right for you. BTW, the only thing she said is bad on septic systems is soap. It kills the crap eaters. If you have a seperate black tank this is really a non-issue. Of course, in an RV environment, we don’t let the contents in our tanks sit long enough to really promote any real breakdown of solids so tank configuration doesn’t really matter.

[needtocamp]

Nope, don’t use the chemicals either, but find it hard to believe there is any aggressive bug eating going on in our holding tanks when they’re emptied, flushed and cycled often while using the coach.

Those with a direct drop (discharge) to the black holding tank better not have the bathroom fan running when flushing, peeeuuuuu.

[Jim]

Some of the holding tank chemicals designed to control odors are actually going to kill bacteria and if the RV park has a septic system the chemicals may damage their bacteria. Bacteria in a sewer system and treatment plant are necessary, and some locales such as NYC use bacteria to digest waste (such as grease) that would create blockages.

[Jim]

These comments don;t directly address your issues, but when I’m in an RV parks, both tanks (or, in my present situation, my tank singular) are left open. I’ve had no issues with clogging/dirty tanks but I do use chemicals and slosh my tank thoroughly as I drive down the road.

[Dorene]

wow, thanks for all the inputs. Today after work, weather permitting, I’ll do a strait water flush. Hopefully that will remove any remaining solids in the black.

I need to check all of the vents y’all mention. Maybe we do have a failed The stink only happens when the black goes over 1/2 and the gray is 3/4. Temp fix is to dump early and often.

thanks to all

[Archived]

I didn’t mean to re-ignite the chemical/no-chemical debate that rages on all RV forums. I’m not a fan of chemicals. However, for those of us with an electric flapper toilet that creates a brief direct path to the black tank whenever we flush, a little bit of chemical fragrance is welcome in the heat of summer, regardless of how well our sewer system is sealed or how often we dump.

[AL]

Bryan,

Great point. Flapper base toilets are temporarily open to the holding tank during the flush cycle.