Lavac Flush Water Problem

[bh100014]

I have been pulling my hair in trying to fix the problem with the sea water flush for the Lavac toilet on my sailboat. Any suggestions will be much appreciated! I've had this boat for nearly two years and the toilet has been working fine until this spring. It began to get harder and harder to draw the flush seawater in, and eventually there's hardly any water being sucked in at all. I've pretty well taken apart the whole system, multiple times, to find the root cause but so far no luck.
- The same seawater intake also feeds the Lavac in the forward head, which works fine, so intake is not a problem.
- The inlet hose runs from the seacock and loops to about 5 ft above waterline and to the toilet; the height seems reasonable.
- The inlet hose goes through two right-angle joints. The clamps are tight and there's no air leak that I can detect.
- There's a small red plastic plug inserted into the hose at the top of the loop and I assume that's the bleed value. The bleed hole must be very small as I can't see it. In any case I can detect no air leaks there.
- The Lavac seems to work fine and draws a vacuum just like my other head. The seat gets sucked down and stays down for 20 seconds or so. But little water gets drawn in, and the bowl stays empty regardless of how many strokes I pump.

Ideas?

Thanks
Ben

[mbianka]

Originally Posted by bh100014

I have been pulling my hair in trying to fix the problem with the sea water flush for the Lavac toilet on my sailboat. Any suggestions will be much appreciated! I've had this boat for nearly two years and the toilet has been working fine until this spring. It began to get harder and harder to draw the flush seawater in, and eventually there's hardly any water being sucked in at all. I've pretty well taken apart the whole system, multiple times, to find the root cause but so far no luck.
- The same seawater intake also feeds the Lavac in the forward head, which works fine, so intake is not a problem.
- The inlet hose runs from the seacock and loops to about 5 ft above waterline and to the toilet; the height seems reasonable.
- The inlet hose goes through two right-angle joints. The clamps are tight and there's no air leak that I can detect.
- There's a small red plastic plug inserted into the hose at the top of the loop and I assume that's the bleed value. The bleed hole must be very small as I can't see it. In any case I can detect no air leaks there.
- The Lavac seems to work fine and draws a vacuum just like my other head. The seat gets sucked down and stays down for 20 seconds or so. But little water gets drawn in, and the bowl stays empty regardless of how many strokes I pump.

Ideas?

Thanks
Ben

Ben:

I'd amost be willing to bet that your bowls intake fitting or intake hose is clogged with some marine growth or debris.

[rebel heart]

Gross picture, but check out the amount of buildup in my lavac's hoses.

Rebel Heart - Sailing, cruising, liveaboard blog and website - Eric's Blog - oh wet plumbing system, how foul and disgusting art*thou

[mbianka]

Originally Posted by rebel heart

Gross picture, but check out the amount of buildup in my lavac's hoses.

Rebel Heart - Sailing, cruising, liveaboard blog and website - Eric's Blog - oh wet plumbing system, how foul and disgusting art*thou

Rebel heart:

But. his problem appears to be with the intake side of the Lavac not the output side. BTW how many years was that build up in you hoses? Yikes!

[sarafina]

oh man. Dude, that is NASTY...


Our composting head arrived a week ago and is sitting in the hall (otherwise known as the haul...) waiting to go to the boat for install. We went with the c-head and are pretty excited. We can trade tips on effective usage ; -)

But them there hoses... way yuck ; -)

Worse than the diapers I bet!!

[HopCar]

Interesting problem. My bet is a blockage in the intake hose at one of the elbows. The red plug at the top of the loop is a puzzle. Normally you wouldn't have a vent in the intake hose of a toilet. The proper place for a vented loop is between the intake pump and the bowl and also in the discharge hose. The vents should always go in a pressurized hose, not a suction hose. Since you can't see a hole in the red plug, it probably isn't a vent.
This brings up the question of how do you prevent a Lavac from siphoning? You can't put a vent between the intake pump and the bowl as you would do on a more conventional toilet. Peggy Hall, where are you?

[rtbates]

The only time our LAvac doesn't suck in water is when the seat doesn't seal so we sit on it and pump. The only other reason possible is a blocked input line...

try sitting on it and pumping..

[rtbates]

Originally Posted by HopCar

Interesting problem.
This brings up the question of how do you prevent a Lavac from siphoning? You can't put a vent between the intake pump and the bowl as you would do on a more conventional toilet. Peggy Hall, where are you?

reach over and close the seacock!!!

Baring that there is, or should be per Lavac, a valve with a small hole mounted in the intake path at the top of the loop. This should break any siphoning I do believe.. The size of the opening determines how much water ends up in the bowl after pumping, so yes, it's breaking the siphon or else the bowl would over flow

[bbalan]

Returned to the boat after having been away for a couple of months. Was having the same problem as you. Turns out there were a lot of little fish living in my thru hulls and one of them got sucked up in the intake hose after I opened the thru hull and pumped the head. The fish was in the inlet to the BOWL itself. I was able to remove the intake hose and pull the fish out and all was well. But your blockage may be further in. Might try attempting to suck some bleach in through the intake.

The red plug is, indeed, the bleed valve. Very important part of the system. Make sure it stays clear... otherwise you get a little too much water in the bowl. (HopCar, this is the absolute correct place for the bleed plug on a Lavac).

I've had 2 Lavacs for 15+ years and they are awesome.

Cheers,
Bruce
s/v Migration
Lautoka, Fiji

[HopCar]

Bruce and Randy, That is interesting information about the vent in the Levac intake line. I guess that huge diaphram pump can handle the little bit of air introduced by the vent. On toilets with smaller pumps it's enough to cause loss of suction. Now that I think about it, I see that it would put a limited amount of water in the bowl when you quit flushing so you don't start off with a dry bowl the next time. Those Levac guys are pretty clever.

[PEACETIME]

Try removing the intake hose from the bowl and instead replace it with a short section ending into a bucket with water. Then try to pump and see if the unit works normally. If it does then you will need to trace the intake hose back to the Y that must be in the line as you said there are two lavacs using the same thru hull. Good luck

[bh100014]

Everyone, thanks for the input.
I put in a by-pass hose from the seawater intake to the bowl, and it draws water fine. So the problem is somewhere within the hose, even though it seems to keep the pressure (the seat does stay sucked down). I think I will just replace the old hose.

Ben