Lavac Installation

[newportknots]

Afternoon,

I'm about 90% of the way through an installation of a new Lavac Popular. I've got it set up so the head pulls flush water from the freshwater tanks on board. The inlet has a vented loop above the fresh water tank in a locker and runs directly to the toilet. The same is true for the discharge hose, which runs through a vented loop before a Y-valve either leading to a thru-hull or waste tank.

Here's my question: The Lavac documentation show both the inlet hose and discharge hose vented with a small vent plug. They direct you to drill a small hole on the crest of the loop and insert the plug.

Do my vented loops accomplish the same goal? Or should I use the plug method in tendem?

Thanks, Mike

[sailingdog]

I wouldn't have the Lavac pull water from the freshwater tanks. If there is any back flow, you could seriously risk the health of your family by contaminating the potable water system.

It would make much more sense to plumb it into the drain of the head sink, with a diverter valve that allows the head to either drain overboard or be used to flush the head. That would eliminate any risk of contamination whatsoever, and allow you to flush using grey water... which is a better use of fresh water resources on a small sailboat.

IMHO, you'd also be better off running the Lavac's discharge hose directly into the holding tank, and then putting the y-splitter in the pumpout hose of the holding tank and adding a diaphragm pump to the side of the "y" going to the seacock and through-hull.

This would give you a much more flexible waste handling system, since you could pump the holding tank overboard whenever you're out past the three-mile limit, and don't require a pumpout facility or boat. You really haven't lost any functionality, since anywhere you could have pumped the head directly overboard, you can empty the holding tank.

Using the vented loop may cause the Lavac to have some problems flushing properly.

[soulesailor]

The intake loop on my lavac, which comes directly from a thru-hull, has the lavac anti-syphon device. The output hose, which goes to a pump and then a diverter valve (one way to overboard, one way to holding tank) is vented with an anti-syphon valve I bought at a hardware store.

Both of these plugs work fine every time and there is no chance of creating a syphon on either side of the toilet, which is the low spot in the loop. Make sure your vented loops are above the SEAWATER level and not just your freshwater tank level.

Why are you using freshwater, by the way? That's gonna drain your tanks pretty fast and, as dog said, could create some problems. Remember Murphy's Law: if it can go wrong, it will.

[newportknots]

Dog - that is a flexible system and I like the idea of being able to pump out the tank myself past the 3-mile mark.

Soul - I went with freshwater to try and eliminate some of the odors associated with flushing with seawater and little guys living in the discharge hose. If I could use grey water that would be the best of both worlds.

So-plumb the intake of the Lavac to the sink drain with a diverter valve..hmm. Would that mean running water into the sink every time I wanted to flush?

[sailingdog]

You could use a diverter valve in the intake line and have both a saltwater option and a greywater option... That's how it is setup on my boat.

Otherwise, yes, you would have to run water into the sink every time you wanted to flush... but you do wash your hands after using the head, don't you???

Originally Posted by newportknots

Dog - that is a flexible system and I like the idea of being able to pump out the tank myself past the 3-mile mark.

Soul - I went with freshwater to try and eliminate some of the odors associated with flushing with seawater and little guys living in the discharge hose. If I could use grey water that would be the best of both worlds.

So-plumb the intake of the Lavac to the sink drain with a diverter valve..hmm. Would that mean running water into the sink every time I wanted to flush?

[newportknots]

Ah ha - that I do. Well, most of the time. = )

[sailingdog]

LOL...then you should be all set...most of the time...

Originally Posted by newportknots

Ah ha - that I do. Well, most of the time. = )

[mitiempo]

Use the Lavac supplied vent plug on the inlet loop, by itself and not in conjunction with the antisiphon vent you bought - the hole in the Lavac plug determines the amount of water left in the toilet bowl. Use the antisiphon vent in the outlet loop where ever it goes - overboard or holding tank.

[Valiente]

Once you get the hang of it, you will love your Lavac. It was what convinced my wife to buy our cutter...she said "is this the one that will flush a pair of jeans?"

A curious claim, really...