420: Backflow into Head

[Blc7]

I have a 2007 owner's version Lagoon 420. I've replaced the head on the owner's side with an electric head. Both heads (Jabsco) on the guest side are continually leaking water back into the head from the outflow hose which goes into the holding tank.

I've replaced the joker valves and base valves multiple times, I've even replaced the pumping unit on both. It seems like they work for 1 or 2 flushes then water seeps back into the head causing quite a smell (which my wife has informed me she doesn't like!).

I had my boat repair guy over today and his opinion is that it is a design flaw with the Lagoon 420 that the 4 ft or so of ~1.5 inch hose which goes from the head to the tank creates too heavy of a water column for the valve to keep from seeping in. He doesn't feel there is much to do about it.

Any suggestions??? I need to keep the wife happy!

[Wrong]

Originally Posted by Blc7

I have a 2007 owner's version Lagoon 420. I've replaced the head on the owner's side with an electric head. Both heads (Jabsco) on the guest side are continually leaking water back into the head from the outflow hose which goes into the holding tank.

I've replaced the joker valves and base valves multiple times, I've even replaced the pumping unit on both. It seems like they work for 1 or 2 flushes then water seeps back into the head causing quite a smell (which my wife has informed me she doesn't like!).

I had my boat repair guy over today and his opinion is that it is a design flaw with the Lagoon 420 that the 4 ft or so of ~1.5 inch hose which goes from the head to the tank creates too heavy of a water column for the valve to keep from seeping in. He doesn't feel there is much to do about it.

Any suggestions??? I need to keep the wife happy!

Solution:

[Blc7]

I don't think that would keep the wife happy.

[Delancey]

Not sure if it is a "design flaw" as at the top of the 4' of hose there should be vented loop. This arrangement should prevent back flow from an open seacock sinking the boat. Sorry, not a solution but an explanation.

We have a somewhat similar situation, a work around we live with is to give plenty of pumps after the dirty work so that the standing column is all clean water. As they say the solution to pollution is dilution!

[Wrong]

Originally Posted by Blc7

I don't think that would keep the wife happy.

Ditch the wife.

[Blc7]

Originally Posted by Delancy

Not sure if it is a "design flaw" as at the top of the 4' of hose there should be vented loop. This arrangement should prevent back flow from an open seacock sinking the boat. Sorry, not a solution but an explanation.

We have a somewhat similar situation, a work around we live with is to give plenty of pumps after the dirty work so that the standing column is all clean water. As they say the solution to pollution is dilution!

Thanks, Delancy. I'm not sure that backflow from this hose sinking the boat would be a problem. The hose flows into the holding tank which is then vented well above the water line. There is no vented loop in the hose from the head to the holding tank, but I'm not sure that would help.

And, Unfortunately, I've found it is even hard to pump enough water into the hose to dilute it much.

[ShaktisBoy]

Get a composting head and be done with all that nonsense. Airhead is my favorite for several reasons but there are plenty of people who like the natures head. Just keep in mind your dealing wih human waste on a on a boat not connected to any municipal waste system. There is no perfect system. On our boat the owners side has an airhead and my wife and i live aboard about 90% of the time. With just the two of us I must empty the unfinished compost about once every 3 months. Its not fun but it only takes 5 minutes. Unscrew 4 thumb screws, place large hefty bag over the entire unit and invert. Place unit back in its spot recharge with composting medium and replace thumb screws. Take the large trash bag place in 5 gallon bucket with lid with some small holes in lid and dispose of shoreside for final composting. In about 3 a 4 months the material is pretty much composted, i.e no smell. The guest side still has a standard marine head. That damn thing is constantly giving us a problem. We keep it because the idea of a dry toilet is just to wierd for some people to handle. They all have a misconception of a composting toilet being like an outhouse, when in fact it there is no smell in the head, the unit looks like a real toilet is simple to use and won't ever clog up. Depending on your installation you can get rid of one or both of your toilet through hulls. There is a removeable urine jug on all of these units,"you dont want urine to mix in compost" that has to be dumped more frequently, every 3 days or so. I hated that so I kept my existing holding tank, plumbed a line and 12v liquid pump from the urine jug to the top of the holding tank. Now with the flip of a switch I empty the urine jug into the holding tank. The holding tank now has only a single hose to the through hull "toilet out". The line your having an issue with has been cut short and corked. With this arrangement we can use the holding tank for several months without needing a pump out or having to go offshore to empty the tank. Pretty soon I think Im going to rip the guest side head out and do the same thing. If our guest arent open minded enough to give it a try I dont need them onboard.

Anyway good luck with this.

[HopCar]

That's often an issue when the holding tank inlet is higher than the toilet discharge.
Some people have added another check valve after the toilet but that doesn't work for long.

How about replacing the manual toilets with macerating electric toilets? You can then reduce the discharge hose from 1-1/2" to 1" so it will hold less water and it will be easier to pump clean water all the way to the tank.

Jabsco 12 Volt Toilet - 37010-0090

[Scott Berg]

Sealand check valves work much better than most for this

[Tim R.]

I have a similar setup and the joker has no problem holding back a column of water 3 ft. above the head. I am not sure if the toilet can handle this but what about a second joker valve?

[Blc7]

Originally Posted by HopCar

That's often an issue when the holding tank inlet is higher than the toilet discharge.
Some people have added another check valve after the toilet but that doesn't work for long.

How about replacing the manual toilets with macerating electric toilets? You can then reduce the discharge hose from 1-1/2" to 1" so it will hold less water and it will be easier to pump clean water all the way to the tank.

Jabsco 12 Volt Toilet - 37010-0090

This is exactly the conclusion I have reached, today. I am going to try an additional check valve (very inexpensive attempt at solution). If that doesn't work, I will replace the head with an electric. As I stated in the OP, I did that in the owner's side and I've had no problem. I was hoping for a less expensive solution, though.

[HopCar]

A little off topic, but not much, Practical Sailor tested Groco, Jabsco and Raritan joker valves. They said they are all interchangeable and that the Jabsco design was best at stopping back flow. I think Groco was their best value pick.

[Tim R.]

Originally Posted by Wrong

Solution:

My wife says "So Wrong"

I am surprised you allow yourself the luxury of a seat

[wsmurdoch]

Originally Posted by HopCar

A little off topic, but not much, Practical Sailor tested Groco, Jabsco and Raritan joker valves. They said they are all interchangeable and that the Jabsco design was best at stopping back flow. I think Groco was their best value pick.

I just re-read the article in the July issue of Practical Sailor. I can see the photo of the test setup where they subjected the three valves to a 30" water column and measured the backflow, but I do not see the results of the testing.

On the Jabsco they seem to like the three corner design saying, "Because of its unique three-corner design and softer compound, it opens wider (presenting 60-percent greater area than Raritan and Groco). It creates less pumping resistance and greater clog resistance than any other valve." But, they don't say anything about backflow for this valve.

I wrote Practical Sailor, and they say they will print the backflow results in a later issue.

I have a manual Groco that sometimes leaks back. I have thought about adding a quarter turn valve after the duckbill and before the vented loop, but I do not have a good place to install it.

[HopCar]

"But, they don't say anything about backflow for this valve. "

Well I was almost right. Darn that CRS.