Levac plumbing question

[Fishspearit]

So the boat I bought has 2 levac heads, great, I hear wonderful things about them. But I've never used one before, and apparently no one at my marina has one either. I was having trouble getting water to fill the bowl when I pumped, noticed lots of hissing air noise, and finally discovered that both seawater lines had pinholes in them. Same place on both lines, at their highest point about 3 feet above the waterline before going down to the throne. After wrapping the pinholes with duct tape, I get water flowing back into the bowl, but still plenty of hissing because I didn't completely seal them. So, my question is, are these 'vents' in the loop necessary to keep from siphoning, and just a cheesy way of doing it? Or is it just a strange coincidence that they both got holes in similiar places? Is it ok with a lavac for me to replace the hoses and not worry about venting the loop?

[AdamY]

the holes are as designed.

you need to close the lid to create a vaccum and get water pumping in. there should be a sticker that explains how they work that came with the toilets we put our sticker on the wall.

they should hiss as this is how the siphon is broken. the bigger the hole the more water remains in the bowl. in this case "cheesy" to me translates to "brilliantly simple"

cheers,

[Boracay]

The anti syphon holes are essential.

Without them if you forget to turn off your seacock or don't notice, a below the water line bowl will overflow and sink your boat.

[hellosailor]

Lavacs are generally considered top quality thrones. I'd suggest contacting the maker to get an instruction/repair manual for them. The seal on the bowl/lid is a consumable part, yours may simply need replacement.

[Nauticatarcher]

If lid doesnt suck down to bowl and create vacuum uou need new lid seals, there is one under seat and one under lid, small pinhole breaks vacuum slowly and size of hole determines how much water is ileft in bowl

[Steve Pope]

Google "blakes lavac"everything you need to knows is on line.

[GordMay]

Lavac Toilet User Manual:
http://www.blakes-lavac-taylors.co.uk/pdf/lavac.pdf

Lavac Toilet FAQs:
FAQs

Lavac “Zenith”
Lavac Zenith

Lavac “Popular”
Lavac Popular

Blakes Lavac Taylors Email:
info@blakes-lavac-taylors.co.uk

[Fishspearit]

Thanks for the links GordMay. It seems that there is supposed to be a plastic bleed plug in the line to control the vacuum. From Adam Y's post it sounds like mine is not the only one where somebody just poked a hole in the hose rather than installing the bleed plug.

The seals on the bowls are in good shape.

Of course, the pinholes were put in the hose in a place where they pass through a difficult area to access. Oh well, better than working on the other end of the plumbing.

[hellosailor]

Fishspearit-
Some silicon or butyl self-vulcanizing tape, or some bicycle inner tube, should be able to wrap over that hole and securely close it up if you want to. It will conform and seal way better than duct tape will, and be easier to remove when you want to.

[Northeaster]

I bought and installed a lavac popular last year. I installed an antisiphon loop and valve in the fresh water hose, forgetting about their "valve". After having trouble pulling water into the bowl, with the lid down, I ordered a new valve from lavac. I was happy with the seemingly reasonable price of approx. $7, until I actaully received the valve in the mail! Trust me, you are not missing anything by having a pinhole in the hose, rather than the propper valve - as mentioned earlier, adjusting the size of the hole is supposed to control the amount of water left in the bowl.

[Fishspearit]

Just to clarify, it's my suspicion that the larger the vent hole, the faster the siphon will break, and less water will remain, and this

Originally Posted by AdamY

the bigger the hole the more water remains in the bowl.

is wrong? Or am I backwards, because it sure seemed like partially covering the hole made more water come in.

[Roy M]

Lavac toilets are the best, but they take a little adjustment getting used to. The place they are NOT good to have is a head that gets LOTS of use in a very short time (read: only toilet at a beer chugging party). The toilet depends on developing a partial vacuum when the bilge pump is activated. The waste is pumped out and the clean saltwater is drawn in by the creation of the partial vacuum. The seat and toilet lid are pulled shut, against the silicone rim seals. It takes a couple minutes for the seal to break, unless you have one of the following: a pet-cock (or similar valve) in the seawater INTAKE hose, or a damaged or dirty seal that allows wair to leak back in while pumping waste out. If you need immediate reuse of the toilet, insert a small petcock valve. The previous owner achieved a similar solution by putting a pinhole in the intake hose. The problem with that solution is that it dribbles salt water when being pumped. You can also draw a circle around the pinhole with a magic marker and place a finger over the hole while pumping. Wait a couple seconds after pumping to allow the water level to rise (you can judge that with experience) and then remove your finger to release the vacuum. Once you and your guests understand this principle, you will never go back to conventional marine toilets, unless you love complexity and frustration.

[Delezynski]

A quick note on using a Lavac...

We have been using ours for a LONG time and it works GREAT even when used often. Here is how we rigged and use it.

We put the water intake loop with a vacuum break valve in the head on the bulkhead above the Lavac.
We then removed the small flapper valve in the break valve. That leaves a small (apx. ¼ inch open hole).

The outgoing vacuum break is in another compartment.

To use:
open through hulls.
Put a finger over the in-head valve and pump the handle about 3 or 4 times (for us) with the lid closed.
Open lid to see water in the Lavac.
Use it as needed.
Close lids and once more put finger over the valve and pump a few ( 4 or 5 for us) times.
Remove finer and pump a few times and you have a dry bowl that is ready start again with no waiting.

Because of the lid seals, if you don't pump right away, you never get any smells from the unit.

Hope this helps!


Greg

[Boracay]

I installed the LAVAC with a holding setup using the KISS system.

I have forgotten to close the inlet seacock a few times and the boat still floats.

I mounted the holding tank a bit high so that it would drain properly.

Only problem is that it is hard to pump the extra distance and some sewerage always backflows unless real care is taken with pumping (Double pumping is helpful).

If I was to do it again I would go for a tank that was much wider with the top the shortest possible distance above the toilet.

If maximum holding tank capacity is needed it might even be worth while to install a second holding tank using an electric pump to empty the first tank as the increased capacity is probably mostly only needed at marinas.

[Roy M]

Boracay, How high is the lift? A Henderson or Whale bilge pump is easily capable of evacuating all of the waste at least three feet to the top of the holding tank. A couple pumps extra and you have only clear saltwater that might fall back into the toilet. Give it a try, and try to make the initial section of hose go entirely vertical, then drop down at 1/4" per longitudinal foot to the holding tank inlet.