Head smell every time Vacu Flush is used...

2000 390 MS with Vacu Flush toilet. Now I am getting a foul smell every time toilet is flushed. Anyone know where the air filter is located on this boat? And what kind of filter am I looking for? In line?


Any help is appreciated from fellow 390 owners.



Gordon

It’s not that. Is this a salt water flushing head? If so, it’s the sea water that grows organisms that stink. This forum has a lot of good advice on the matter elsewhere.

On my other boats that use sea water to flush that is true, but my Vacu Flush toilet uses just 1 pint of fresh water from my water tank, so no organisms to die and smell.



Never had this problem before.



Is this an indicator my holding tank is full? The Raritan Accu gauge installed always says 1/2 full...kind of useless.

Is the odor inside the boat (for instance coming from the bowl when the "dome" is open), out the tank vent, or both?

Accugage is not a Raritan product...it was made by Snake River Electronics (now out of business about 10 years. It's relatively easy and inexpensive to replace a failed sender.

--Peggie
"If you can't explain it to a six year old, you don't completely understand it yourself." --Albert Einstein

And btw... Despite Dometic/SeaLand's claim to the contrary, 1 pint of water is not nearly enough to rinse waste out of the hoses and pump. At least 90% of VacuFlush problems are a result of using too little water.

Always leave the pedal down at least 3 full seconds following urine only...always add about half a bowl of water ahead of solid waste and leave the pedal down 7-10 seconds to rinse the system behind the flush.

I've written piece I call "VacuFlush 101" that explains how the system works (an amazing number of owners think they know, but don't) and how to prevent problems. If you'll send me a PM that includes your email address (no way to attach anything to a PM), I'll send it to you (and to anyone else who'd like to have it.).

--Peggie
"If you can't explain it to a six year old, you don't completely understand it yourself." --Albert Einstein

Peggy, the smell (extremely foul) appears to be external, so I am assuming coming from the holding tank vent. I can smell it in the cockpit, and also when on the fly bridge when the toilet is used. And yes, we do 3 seconds urine, and double that for solids, so water usage is a bit more than what the factory claims.


Any idea where that vent is located? On my 390, the only access to the Vacu Flush "box" is at the small floor hatch at the lower helm...you have to be extremely small to get down there.



Is that where I will find the holding tank vent filter? I had guests on board this weekend and was embarrassed by the foul fumes each time toilet was used...thank goodness for a windy day so had to deal with it for just 10-15 seconds...

You need more oxygen in the holding tank. Aerobic bacteria does not smell. Anerobic bacteria does smell quite bad. The vent will block airflow into the holding tank. Actually you need 2 vents, one on each side of the boat to promote airflow through the tank. If you cannot put 2 vents then use something like a Groco Sweetank. It pumps air into the tank and the discharge air coming out of the vent will not smell.

The holding tank is installed at least a couple of feet after the vacuum generator ("box")...there's a vent line coming off the top of it that goes to a thru-hull well above the waterline. Any vent filter is in it. You may have to hire a short skinny teenager to get to it to replace it. NEVER let the tank overflow out the vent...if a filter gets wet, it's not only toast immediately, but the charcoal can swell up and block the vent, which can cause major problems.

Dave is correct that you really need to increase the amount of oxygen in the tank, you'll find detailed info about how to do that in my book (see link in my signature). Meanwhile...What if anything are you using in the tank? Whatever it is, pump out the tank and thoroughly rinse it out and switch to a product called No-Flex Digester Noflex Digestor. It's getting rave reviews everywhere.

--Peggie
"If you can't explain it to a six year old, you don't completely understand it yourself." --Albert Einstein

HeadMistress said:

pump out the tank and thoroughly rinse it out and switch to a product called No-Flex Digester Noflex Digestor. It's getting rave reviews everywhere.

Click to expand...

We’ve been using Noflex Digestor for several months. It’s a great product. Strongly recommend.

Paul

Short term easy fix is to throw some KO at it. Mine stays odorless if being used regularly, but will sour sitting for a week. One shot of KO when I get on the boat and everything is good in an hour or two. Just picked up a whole gallon for free. The stuff also works on pet stains, and with overly gregarious Company VP’s(held to secrecy on that one).

suntansailor said:

Any idea where that vent is located? On my 390, the only access to the Vacu Flush "box" is at the small floor hatch at the lower helm...you have to be extremely small to get down there.

Is that where I will find the holding tank vent filter?

Click to expand...

The vent is often in the same general vicinity of your pump-out fitting, on the hull side, often maybe 12" below the rub rail.

If you can see the top of you holding tank, you should be able to identify the vent hose, usually smaller in diameter than the pump-out hose but generally running in the same general direction (assuming vent location as above).

Trace the vent hose toward the vent, and the filter should be in there somewhere. Likely a Sanigard (?) inline filter with garden hose fittings in each end. You'll probably have an access port somewhere to get to it, maybe in a bulkhead or behind a locker or etc.

-Chris

Make sure your vent hose does not have any dips where water can collect. If it does you'll end up with the equivalent of a trap you'd find under a sink. The water would block the free flow of air necessary to avoid tank smells.

A simple check for it is pull the vent hose off the filter (assuming one is present) and blow air into it. If you hear a gurgle there's water in there. Obviously you'd want to avoid breathing in through it, or putting your mouth directly on it. If there's water you need it removed. If there's no air flow then there's an obstruction. Check the hull fitting to see that it's clear of any debris (insect nesting, etc). I'd avoid using any kind of high pressure air otherwise you risk blowing the line off a fitting that might be very hard to reach.

If you have a filter, take if off and throw it away! Filters are the worse thing for a holding tank. They block to much fresh air and like comodave said you need plenty of fresh air. I have a 1 1/2 in vent on my boat and I use Noflex Digestor.
No stink ever. Noflex Digestor will clean you lines and tank also.

ghost said:

Short term easy fix is to throw some KO at it. Mine stays odorless if being used regularly, but will sour sitting for a week. One shot of KO when I get on the boat and everything is good in an hour or two. Just picked up a whole gallon for free. The stuff also works on pet stains, and with overly gregarious Company VP’s(held to secrecy on that one).

Click to expand...

I think KO works great, but it will only work in a system that has plenty of air exchange to provide enough O2. My guess is that the OP doesn’t have enough venting to provide that O2.

on our 390 we had the same issue except with electric flush. The vent line filter was in the compartment below the lower helm and towards the holding tank (amidships). I removed the filter completely and just connected the two lines together. Problem went away within a day or two.
John

Your vent is by the starboard side fuel fill. Remove the access panel and you will see it. It probably has NO filter. I installed an inline, homemade filter using PVC tubing, activated charcoal and filter mt;l. Found it on Youtube. Works great!
I would also replace the entire vent line while your at it.

kenk" If you have a filter, take if off and throw it away! Filters are the worse thing for a holding tank. They block to much fresh air and like comodave said you need plenty of fresh air." I'm with kenk,inline filter block air that is necessary. If possible add another vent line ,increase the existing vent diameter. You need air entering system not blocked by a filter.

If you cannot get a larger or 2 vent lines then get rid of any filters and put in a Groco Sweetank. It pumps air into the tank continuously so you don’t need the second or even a larger vent. Simple install took me about 45 minutes on a previous boat once you get over the fear of drilling a 2” hole in the top of the holding tank...

Comodave said:

Simple install took me about 45 minutes on a previous boat once you get over the fear of drilling a 2” hole in the top of the holding tank...

Click to expand...

I have to admit that this is what has kept me from doing it so far. I really hate drilling or cutting holes in my boats. Fear of really screwing it up. The Groco is great but I think if I get over the fear of drilling the hole I might just attempt a roll-your-own and save some money.

It would be easy enough to make your own. As to drilling holes in your boat, I would not have any problems drilling...

UPDATE:



All, thank you for all the suggestions. I found a "small" worker that was able to get down into that floor hatch at the lower helm. We located the vent tube from the holding tank, it was not blocked. There was no filter installed, so I installed the Dometic ECO filter and dated the install. Almost immediately the foul smell disappeared.



https://www.defender.com/product.jsp?id=2853136



The whole process took less that 20 mins to install and eliminated all the foul smells. I like simple solutions to boat issues...

Greetings,
Mr. S. As many have said already, toss the filter. It may have temporarily eliminated the odor BUT it is a band-aid fix. More air to feed the aerobic bacteria is the ONLY viable, long term solution.

I like simple solutions to boat issues...


As long as you're ok with just treating the symptoms instead of curing the "disease." The cure is also pretty simple on most boats.



--Peggie
"If you can't explain it to a six year old, you don't completely understand it yourself." --Albert Einstein

Vent screens

I have found that many boats have a screen in the vent outlet. The first time the holding tank vent line gets "stuff" in it ,the vent stops venting well. Pull the screen out and chuck it. This should allow more air/oxygen in.

For what it is worth.... What are the conditions of your blackwater hoses? As they age they can get soft and sticky and allow orders to permeate the hoses. Worth checking and possibly replacing as you troubleshoot.

suntansailor said:

2000 390 MS with Vacu Flush toilet. Now I am getting a foul smell every time toilet is flushed. Anyone know where the air filter is located on this boat? And what kind of filter am I looking for? In line?


Any help is appreciated from fellow 390 owners.



Gordon

Click to expand...

As you can tell from reading the very many posts on “stink” here in the forum there are those who strongly advocate curing the problem thereby eliminating stink and those who prefer to just eliminate the stink and ignor the problem. I am in the “just eliminate the stink” camp.

I chucked the original filter but the replacement cost was in the $90 range. I solved my stink by purchasing a water filter along with a replaceable charcoal cartridge and put that into my vent line. No more stink. I don’t care that there may be stink in my holding tank nor do I care that there may be stink in my home’s ceptic tank as long as we do not have to smell it. And we do use fresh water flushes both on the boat and of course at home.

Comodave said:

It would be easy enough to make your own. As to drilling holes in your boat, I would not have any problems drilling...

Click to expand...

Here's my DIY "Groco" tank aerator - see Holding Tank Aeration
Bacchus Projects

Only change is I replaced the copper tube w a PVC. I've also found a manifold w/ many small holes doesn't seem necessary - just get the air into the tank.
The 12V aquarium pumps are pretty cheap and reliable. This one has run 24/7 for several seasons. When it dies I'll just order a replacement.

I tried the noflex on a really poorly installed vacuflush system. Both the boat owner and I were amazed. He said his boat has always stunk after a flush. After noflex there was no stink at all.

Bacchus said:

Here's my DIY "Groco" tank aerator - see Holding Tank Aeration

Bacchus Projects



Only change is I replaced the copper tube w a PVC. I've also found a manifold w/ many small holes doesn't seem necessary - just get the air into the tank.

The 12V aquarium pumps are pretty cheap and reliable. This one has run 24/7 for several seasons. When it dies I'll just order a replacement.

Click to expand...

Yours has been in the inspiration for trying to create one myself. I had already thought I’d use PVC instead of the copper and also thought that it wouldn’t need a lot of holes to provide enough O2.

I just haven’t figure out how to put a hole in the tank that I could seal well.

Drake said:

We’ve been using Noflex Digestor for several months. It’s a great product. Strongly recommend.

Paul

Click to expand...

+1 on Noflex. Solved our odor problem very well. Also, if one owns a holding tank, Peggy's books are the bible. Lots of info surrounding all aspects of keeping the system healthy.

Sidebar - we used to flush the tank when getting pumped. We no longer do that. I think we were flushing all the 'good stuff' each time and had to dose the tank with extra Noflex. Now we just continue with the Noflex at a regular dosage. We live aboard and travel a lot. Thanks to Poseidon, we seem to get the tanks churned up a good bit along the way.