Intermittent waste tank odor

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jaredjensen

Member
Joined
May 25, 2020
Messages
12
Location
United States
Vessel Name
Rendezvous
Vessel Make
1988 Ocean Alexander 420 Sundeck
We have an intermittent waste tank odor in our new-to-us Ranger Tug R29 Classic with a fresh water Tecma Easy Fit toilet. The manual shows a joker valve where the toilet connects to the boat plumbing, but ours just has an open coupling with no valve. I'm unsure if it came this way from the factory or was changed by the PO.

My current theory is that there's enough of a dip in the hose from the toilet to the tank to create a p-trap, but that minor rocking, etc causes enough water to dump to the tank to lose the air block. This was evident the other day as we came off plane and got an immediate strong smell. Also notable, I added water to the bowl and noticed occasional bubbling. Unfortunately, I can't view the area under the head to confirm the hose routing.

I've already added a Big Orange vent filter and confirmed air flow through the vent plumbing, so I'm thinking we need to add a joker valve like this one:
https://marinesan.com/straight-check-valve/

Any advice is appreciated, thanks! Also, I just ordered "The New Get Rid of Boat Odors" and am looking forward to learning a lot.
 
Peggie will likely join in on your discussion.
Her book and knowledge is excellent so follow her recommendations.
My $0.02 is the filter will almost guarantee your tank will smell very bad and add to any smells backing up into the toilet. Best solution is to get adequate air flow in the vent to eliminate the smell at the source (tank).
Vents need to be as short, direct and large as possible with a mushroom through hull instead of the ones with screens meant for fuel.
I and others have had very good success with NoFlex tank treatment along with adequate air to the tank to promote aerobic breakdown and eliminate the bad smell associated with anaerobic breakdown.
 
Welcome aboard Jared! Yo I can see that others were quick to mention Peggie!
 
Welcome aboard. Peggie is the guru on things waste... She will join it sometime. Are you sure you don’t have a joker valve? They are not visible unless you take the discharge hose off. You really don’t want the filter in the bent hose. It will create more smell by stopping air flow in and out of the holding tank. Check you discharge hose for permeation. Use a clean rag with hot water in it, then lay the rag on the hose where it has a low spot. Let the rag dry and then take it and smell it. If it smells then replace the hoses with Raritan Sani Flex hose. Peggie will probably have more and better answers for you also.
 
Are you sure you don’t have a joker valve?
Yep, I've had the toilet out and can see straight down into the discharge hose. It's just a simple coupling.

You really don’t want the filter in the bent hose.
I'm no expert, but I found tons of people recommending the opposite, and vent filters are pretty common on boats and RVs. I'm inclined to keep the filter until it's proven to be a problem.

Check you discharge hose for permeation. Use a clean rag with hot water in it, then lay the rag on the hose where it has a low spot. Let the rag dry and then take it and smell it. If it smells then replace the hoses with Raritan Sani Flex hose.
I can give this a try, and I can also check to see what kind of hoses are installed now. However, I've had the discharge hose wide open when I removed the toilet and there was zero odor coming from it. This led me to the "temporary p-trap" theory I described above. If the hoses were permeated, I'd expected the odor to be fairly constant. But clearly I have much to learn here!
 

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I'm with Dave re NO Vent Filters!
You will be much better off if you can get air into the tank and avoid the smell completely vs trying to keep it in the tank.
This has become analogous to anchor disputes or twin vs single.
Those that have solved their smell problems w/o a filter are much better off.
 
I don’t call myself an expert either but I do have experience with this issue. Peggie IS the expert and she is the one that told me about 20 years ago to never have a vent filter. And she is correct. You want as much air as possible to get into the holding tank. Aerobic bacteria does not smell, however anaerobic bacteria smells horrible. Anaerobic bacteria occurs when there isn’t enough oxygen in the tank. Ideally you would have 2 vents and they would be very large and have one to each side of the boat for flow through ventilation. However the reality is that most boat builders use 5/8” vent hose out one side only. It struggles to provide sufficient oxygen to the tank, particularly when there is a filter in the hose. The filter even if it is clean obstructs air flow. Then if the sewage is allowed to slosh into the vent hose and into the filter, air flow can be obstructed completely. This can cause even worse problems than bad smells such as a crushed holding tank on pump out. So feel free to listen to all those who promote vent filters but please listen to the expert, Peggie Hall.
 
Get rid of the vent filter, make sure the vent is clear then do whatever Peggie tells you to do.

pete
 
Thanks for all the input! I see several recommendations to remove the filter. However, we had the problem prior to adding the filter, and it has at least solved the problem of odor escaping the vent without making the interior odor noticeably worse. So I'm inclined to not remove it until I know it's creating a problem, but will happily do so if I can reliably prevent odor from ever developing in the tank to begin with.

Bacchus said:
You will be much better off if you can get air into the tank and avoid the smell completely vs trying to keep it in the tank.
Maybe this is splitting hairs, but the purpose of the filter isn't to keep odor in the tank. Rather, it's to remove odor from the air on its way out of the tank so as not to annoy neighbors.

Comodave said:
Ideally you would have 2 vents and they would be very large and have one to each side of the boat for flow through ventilation.
Agreed. I struggle to see how a single 5/8" vent line will allow fresh air to enter the tank. I assumed it was instead for allowing expanding gas produced in the tank to escape, along with allowing air to be drawn into the tank during pumpout.

BruceK said:
All you ever wanted to know about toilets, and more:
Yep! As I mentioned, I ordered this book and will be learning a lot, I'm sure! I'm one of those idiots who usually have to learn the hard way.
 
You say the manual shows a joker valve but you don’t have one. One of the things the joker valve does is prevent odor from coming back into a dry bowl.

Maybe you should install one?
 
You say the manual shows a joker valve but you don’t have one. One of the things the joker valve does is prevent odor from coming back into a dry bowl.

Maybe you should install one?
That's definitely what I'm considering, but was looking for feedback before spending the $80 and time to install it. I read lots of reviews stating that the joker valves fail quickly or don't even seal completely when new, which is evident in this photo of a Jabsco valve on Amazon.

But it's a relatively cheap/easy thing to do and clearly indicated in the manual, so maybe I'll just give it a shot anyway.
 
I read lots of reviews stating that the joker valves fail quickly or don't even seal completely when new, which is evident in this photo of a Jabsco valve on Amazon.


HUH? That is not a photo of a failed Jabsco joker valve but rather a new one. The shape is different from the one you showed. Not all have the exactly the same configuration. Amazon did not show the thing properly.

However, yes, ALL joker valves will goof up. They are a maintenance item. They are meant to prevent back flow back to the toilet of what you just pumped out.

Better to have to change the joker once a year than deal with avoidable odours.
 
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Without a joker valve, sometimes called a duckbill valve in the discharge line, there's nothing to stop fumes coming up from the holding tank. If your toilet shows one in the owner's manual and you don't have one, that's your smell problem. I'd never put a filter on the vent line....you want free air flow and it allows you to backflush the vent line periodically at the dock.
 
That's definitely what I'm considering, but was looking for feedback before spending the $80 and time to install it. I read lots of reviews stating that the joker valves fail quickly or don't even seal completely when new, which is evident in this photo of a Jabsco valve on Amazon.

But it's a relatively cheap/easy thing to do and clearly indicated in the manual, so maybe I'll just give it a shot anyway.
Even in exorbitant Australia, a joker valve is $25.95. $14 in USA on Amazon. Jabsco builds `em with a joker valve designed in, it has multiple functions, you don`t have one, you have smells,you need to fit a joker valve. It`s one of the easiest head jobs ( smut humour to sweeten the message).
And check this thread:https://www.trawlerforum.com/forums/s3/head-identification-please-50994.html#post882999
 
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HUH? That is not a photo of a failed Jabsco joker valve but rather a new one.
Ha, yes, I'm aware of that. I said I read many reviews of people buying joker valves that didn't seal even when new, that they could see light through them, etc. The photo on Amazon looks like that brand new one isn't sealing tightly, so their reviews aren't surprising.

Ken E. said:
If your toilet shows one in the owner's manual and you don't have one, that's your smell problem.
Most likely. The fact that the odor isn't constant has been confusing the issue, like when it came out of nowhere immediately after coming off plane the other day. It's also odd that this is a fairly new boat (2012), and the toilet appears to be missing a key component. I'm not sure which is harder to believe: the factory chose to install a simple coupling or the PO chose to remove the joker valve.

Anyway, I'm going to throw in one of these this weekend and cross my fingers.
 
The bottom line here is that this is science. The tank craves oxygen. Filters, even when new, inhibit air flow. Not good.
I don’t call myself an expert either but I do have experience with this issue. Peggie IS the expert and she is the one that told me about 20 years ago to never have a vent filter. And she is correct. You want as much air as possible to get into the holding tank. Aerobic bacteria does not smell, however anaerobic bacteria smells horrible. Anaerobic bacteria occurs when there isn’t enough oxygen in the tank. Ideally you would have 2 vents and they would be very large and have one to each side of the boat for flow through ventilation. However the reality is that most boat builders use 5/8” vent hose out one side only. It struggles to provide sufficient oxygen to the tank, particularly when there is a filter in the hose. The filter even if it is clean obstructs air flow. Then if the sewage is allowed to slosh into the vent hose and into the filter, air flow can be obstructed completely. This can cause even worse problems than bad smells such as a crushed holding tank on pump out. So feel free to listen to all those who promote vent filters but please listen to the expert, Peggie Hall.
 
Thanks for all the input! I see several recommendations to remove the filter. However, we had the problem prior to adding the filter, and it has at least solved the problem of odor escaping the vent without making the interior odor noticeably worse. So I'm inclined to not remove it until I know it's creating a problem, but will happily do so if I can reliably prevent odor from ever developing in the tank to begin with.

Maybe this is splitting hairs, but the purpose of the filter isn't to keep odor in the tank. Rather, it's to remove odor from the air on its way out of the tank so as not to annoy neighbors.

FWIW, we've not had issues with vent filters... in 3 boats and 25-some-odd years. Yes, it keeps from blasting neighbors off their boats. No. it's never contributed to odors in our boats. No, they don't need replacing every year; we usually go between 3-5 years. Yes, Peggie doesn't like them... apparently for good reason... but we've never experienced the symptoms she describes.


That's definitely what I'm considering, but was looking for feedback before spending the $80 and time to install it. I read lots of reviews stating that the joker valves fail quickly or don't even seal completely when new, which is evident in this photo of a

$80?????????????????????????????????????????????????

I think we pay closer to $7 each, or maybe as much as that $10 Amazon price...

The joker valve is kinda self-closing under back-pressure, so even though it appears to be slightly open in that pic... I think the lips come together closer when they're working.

There are other brands, too; Raritan, etc. Practical Sailor did a review some years ago... IIRC, Jabsco's scored pretty well.

-Chris
 
There are as mentioned other Joker valves besides Jabsco units. They simply have a flat slit opening instead of the trilobe opening.

Raritan maybe? I remember the Practical Sailor article but gave the mag. away.

I use the Jabsco myself . WHen new it does not allow back flow. As the unit sits deposits will tend to hold it open more and more. That makes the pumping action less effective and will allow some back flow but without it the back flow will be worse.

Unfortunately all jokers are subject to deposits causing less effective action which is why there are a mtce. item.
 
We also have the Techma head (also on a 2009 Ranger 29) and have intermittent odors outside when flushing. We don't have a vent filter and are fortunate to not have ever had to pull the head apart. Your post says the odor is inside so I don't think whether you have a vent filter matters. I'd say the issue is something else.
 
We also have the Techma head (also on a 2009 Ranger 29) and have intermittent odors outside when flushing. We don't have a vent filter and are fortunate to not have ever had to pull the head apart. Your post says the odor is inside so I don't think whether you have a vent filter matters. I'd say the issue is something else.
There are those that swear by vent filters and those that swear at them! To each his own.
My experience is that if you have a smelly tank it is more likely to eventually find a way inside the boat. If the tank doesn't smell it's easier to avoid ever having it back up into the boat.
Vent filters guarantee your tank will smell terrible but it can be effective at containing that terrible smell until it finds another escape.
My preference has been to fix the smell at the root cause (more O2 to the tank) and I dont have the smell to ever be a problem inside or outside the boat.
 
jaredjensen -

Does your Tecma head have a setting to leave water in the bowl?
I just installed a marine elegance with a pvc discharge pipe pitched entirely to the holding tank. I elected to remove the joker valve right at the toilet since it reduced the pipe size, and -as noted- it will accumulate deposits and eventually stop working. The toilet has a setting to leave water in the bowl for a vapor trap.
 

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Jared,
I am surprised that Peggy has not posted yet, she must be busy.
You have received some good advice so far, but it sounds like you have your own ideas. If that is the case, even Peggy's good advice won't help you.
She has been on this, and other forums for a long time (sorry Peggy :)) explaining over and over why vent filters can be counterproductive! Believe her, or believe the "expert" on your dock (who bought his first boat last week), up to you.
If your tank and system are properly setup with good, unblocked, adequate venting, and your system is used and maintained properly, you should not be experiencing sewage odours inside your boat, nor much smell coming from your vent. Partially filtering odours coming from the vent from a poorly operating black tank is not really a solution, it is only masking the problem, and if it gets bad enough, the odour will find it's way inside the boat and the problem could worsen. Also the vent filter does not help with any odours inside the boat.

Most Joker valves work fine for a while and need to be periodically changed. How often depends on usage and maintenance. Look on this forum for posts regarding cleaning a holding tank (and system), originally posted by OC Diver (Ted). Following his suggestions may be a good place to start (cleaning the tank). If the toilet manual shows a joker, install one and maintain it. I suggest (as I am sure Peggy would) you remove the vent filter and ensure that the vent line is not blocked in any way (even partially). Wipe the hoses down as suggested to check for permeation (smell the rag). Change hoses if they smell. And start using Noflex tank treatment in your system.

A "clean" system, properly vented, using Noflex regularly should not smell.
JMHO, and up to you what you do now. Good luck.
 
THAT Smell....!

I decided to replace my AirForce vent line filter (after spending maaaanny hours trying to clean the fwd bilge areas, etc) and it was a fortuitous event. The PO, or whomever he hired, had failed to install a gasket on one end! As well as leaving that end less than hand-tight (Garden hose size/type fitting)
Replacement of the cartridge was easier than expected; loosened the hose clamps, unscrewed the threaded adapters (which spun in the hose ends), snapped the old cartridge out of the holders, snapped the new one in and installed new gaskets on the ends.
I seriously considered eliminating the filter (as recommended by a sage sailor in this thread) but that would be much more complicated.

We have an intermittent waste tank odor in our new-to-us Ranger Tug R29 Classic with a fresh water Tecma Easy Fit toilet. The manual shows a joker valve where the toilet connects to the boat plumbing, but ours just has an open coupling with no valve. I'm unsure if it came this way from the factory or was changed by the PO.

My current theory is that there's enough of a dip in the hose from the toilet to the tank to create a p-trap, but that minor rocking, etc causes enough water to dump to the tank to lose the air block. This was evident the other day as we came off plane and got an immediate strong smell. Also notable, I added water to the bowl and noticed occasional bubbling. Unfortunately, I can't view the area under the head to confirm the hose routing.

I've already added a Big Orange vent filter and confirmed air flow through the vent plumbing, so I'm thinking we need to add a joker valve like this one:
https://marinesan.com/straight-check-valve/

Any advice is appreciated, thanks! Also, I just ordered "The New Get Rid of Boat Odors" and am looking forward to learning a lot.
 
If you are getting air bubbles back through your toilet, no joker valve ,or duckbill will completely prevent air from seeping through from a holding tank. you have a vent hose that is being blocked by fluid from the tank for some reason ,and when it is not an issue in the vent hose the tank is breathing properly . But if the vent hose is giving any resistance of air escaping problems for the tank .it will choose the easiest way for the air to escape. I suggest you change your venting system for the tank. It is possible that if your toilet is discharging above the level of it's location. you may get some backflow that's left in the discharge hose. my guess is a venting problem .if you get the new sealand then filters ,make sure you take 50% of the foam at each end and cut it out so your filter can breathe easier. I do it every filter only place because it's too much foam being put in the ends now
 
Filters, however modified, inhibit air flow. Never a good idea. Just ask the Head Mistress. A healthy tank does not need a filter anyway.
If you are getting air bubbles back through your toilet, no joker valve ,or duckbill will completely prevent air from seeping through from a holding tank. you have a vent hose that is being blocked by fluid from the tank for some reason ,and when it is not an issue in the vent hose the tank is breathing properly . But if the vent hose is giving any resistance of air escaping problems for the tank .it will choose the easiest way for the air to escape. I suggest you change your venting system for the tank. It is possible that if your toilet is discharging above the level of it's location. you may get some backflow that's left in the discharge hose. my guess is a venting problem .if you get the new sealand then filters ,make sure you take 50% of the foam at each end and cut it out so your filter can breathe easier. I do it every filter only place because it's too much foam being put in the ends now
 
Definitely no filters. They inhibit air flow. You want more air flow into the tank, not less. If anything add a 2nd vent.
 
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