Vacu Flush Puzzle

Last year, when my holding tank cracked, I took the opportunity to replaced all of the hoses, much of it with hard pipe, put a new piston on the pump, changed the vacuum switch and rebuilt the valve/ball assembly...basically went through the whole system.

Now, I've got an odor, quite rank, that seem to be coming from the toilette when it's flushed. This in turn gets picked up by the air handle and distributed, with force, into my daughter's stateroom, and the galley.....yuck.

The only part I had not replaced was the base seal, so today I removed the toilette to replace the seal, which while ready to be replaced, showed no signs of leakage.

I was going to pull the base, but it's pretty well bedded. The area under base is inaccessible, but looking at the diagram of the system, there doesn't appear to be anything that can leak under there, without losing vacuum, which it doesn't. There's also nothing in the bilge that I can find.

I checked the vent hose, and the filter, which while old, can be blown through so I don't think it's a pressure build up at the tank.

So where can this puff of ill wind be coming from? Any ideas?

there is absolutely no way any odor can escape from a vacuflush head or plumbing, since it's under vacuum. it has to be the vent from the holding tank.

Or,you have a leak near the top of the tank which allows air to escape. Check the fittings, make sure they're sealed and tight, especially the tank level gauge fittings.

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Originally Posted by Pascal

there is absolutely no way any odor can escape from a vacuflush head or plumbing, since it's under vacuum. it has to be the vent from the holding tank.

Or,you have a leak near the top of the tank which allows air to escape. Check the fittings, make sure they're sealed and tight, especially the tank level gauge fittings.

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I agree that it's impossible, which is why I'm stumped. For "air" to escape, it has to be on the outlet side of the pump.

I've gone through the fittings on top of the tank...even stuck my head in there while someone flushed. Tightened the top access plate....checked the level gauge. No smell from the top of the tank.

After replacing the base seal, and checking the vent filter, so far, so good. I'm wondering if the fittings on the vent filter were actually loose, which was "fixed" when I took it off and put it back in line, tightening everything down.

Lets hope!

Maybe it's not a smell caused by sewage, but the smell of stagnant A/C condensate that is not draining properly.

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Originally Posted by SKYCHENEY

Maybe it's not a smell caused by sewage, but the smell of stagnant A/C condensate that is not draining properly.

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There is an element of that...it drains, but the coils need to be cleaned....but this is distinctly different to put it gently, and comes and goes in about a minutes time.

I'm pretty sure I have it licked....

I gave every hose another turn on the clamps, and when I removed the filter to check it, tightended the fittings on it as well.

We'll know this weekend.....

I have had the same vent filter on my holding tank for about 15 years. I don't know what is inside it, probably activated charcoal. Do these ever go bad or fill up? Should they be changed once in a while? Never considered it before.

There were no OEM holding tanks in 1966, over-the-side was considered adequate back then. Had to add my tank to replace a functioning Lectra-San flow-through treatment device when no-discharge started coming in vogue. Seems silly to pay money to have a pump out only to have some municipality dump it back in the ocean virtually unchanged. Halifax NS has three sewage plants dumping raw sewage into Halifax harbor. One (!) was converted to primary treatment (strains big pieces out) this month and the harbor was opened for swimming. There is much discussion as to the wisdom of this. And already several beach closings due to bacteria.

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Originally Posted by Fanfare

I have had the same vent filter on my holding tank for about 15 years. I don't know what is inside it, probably activated charcoal. Do these ever go bad or fill up? Should they be changed once in a while? Never considered it before.

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The filters are indeed filled with charcoal. Their stated lifespan is one year. Since they are silly-expensive, I tend to change them when they start failing to do their job....it becomes pretty obvious to your dock-mates when it's time.

When I've changed them, I have found them to be saturated with water, I assume is from condensation.

If you overflow your tank before pumping it out, the filter will be ruined as well.

The environmental effects of overboard discharge have been debated for years. Here, on our lake, the geese and lakeside homes put more stuff in the lake than if every boat on it flushed overboard, but the focus remains on the evil boaters. We can't have the ability to pump overboard, but every time there's a water quality issue, they step up random checks, trying to find that one boat that's cheating, and poisoning the whole lake.

Don't get me wrong, I'm not a proponent of dumping overboard on inland waterways, just pointing out that whenever there's a problem, it's the boats that get looked at first.

yes it is charcoal and they are around $70... sealand says a year (gee... i wonder why) but most last 3 to 5 years)

problem is when they get wet (overflow) the charcoal becomes solid and block the vent resulting in a pressurized tank after a flush, and a collapsed tank when pumping out. not good to say the least.

you can buy charcoal (from aqaurium supply stores i think) and make your own for a fraction of the cost.

never tried to... I dont' have one on my boat. the vent is at the bow under the rub rail and i rarely smell anything coming out of it since we always have a breeze here in florida...

Now, when replacing the charcoal, is it acceptable to use Match-Light?

DAN

you probably already know this, but you can use a water filter for a refrigerator ice maker line. they sell these at home depot for about ten bucks, and it won't matter if they get wet. if you want a larger capacity you can use a regular home water filter with a carbon filter.