Beneteau Sense 43 // lots of saltwater in head shower

[doschhar]

Hello dear Sailors,

I'm an fairly new owner of a Beneteau Sense 43 (2011) and came back to the moored boat after a few days on the road and found the head shower and area with the evacuation drain for the shower full of saltwater (~20 liters).

Normally I close all the valves but of course this time I did not (forgot the ones in the head)

I wonder how saltwater can come into the shower tub any other then via the evacuation opening on the bottom. Checked the system and found it highly unlikely with the pipe layout and pump etc in between ... all I could find was the evacuation felt a little clogged (cleared it).

Maybe someone can share his experience and bring some light into what might have happened.

Thanks for reading.
Harald

[Rohan]

That does sound strange. I assume your head uses raw water from outside? The only possibility that comes to mind is a mechanical/electrical problem that caused the toilet to keep picking up water and overflowing out of the bowl. But I am far from an expert here.

[tkeithlu]

Welcome to the forum, doschhar.

The shower pan is below the waterline, so you don't have to siphon water, right?

From the description, the gray water discharge is below the waterline, so there is a source. How about reverse through the discharge pump and up the drain to the shower pan? We're talking about a slow leak (thankfully; you diodn't find your boat hanging by the mooring lines), so a defect in the gray water stopcock would do the job.

I could be completely wrong; I'm just trying to produce some hypotheses you can test. Consider all the ways seawater can get into the boat. The water is coming in through one of them. Which are connected to the place the water went (the shower pan)? What is the route in each case? Remember that pumps are not seals- water can go backwards through vane and centrifugal pumps.

In the meantime, consider a leave-the-boat checklist, and check frequently until you find this sucker.

[Rohan]

This question could probably get a better answer in the plumbing and fixtures forum.


https://www.cruisersforum.com/forums/f115/

[doschhar]

Originally Posted by Rohan

This question could probably get a better answer in the plumbing and fixtures forum.


https://www.cruisersforum.com/forums/f115/

Thanks for the advice - lets see if I can move the post over there.
Hmm, unfortunately I can not move or deleete this post anymore.

Not sure if opening up multiple posts is a good idea either.

If an admin reads this please move this thread over

[doschhar]

Originally Posted by tkeithlu

Welcome to the forum, doschhar.

The shower pan is below the waterline, so you don't have to siphon water, right?

From the description, the gray water discharge is below the waterline, so there is a source. How about reverse through the discharge pump and up the drain to the shower pan? We're talking about a slow leak (thankfully; you diodn't find your boat hanging by the mooring lines), so a defect in the gray water stopcock would do the job.

I could be completely wrong; I'm just trying to produce some hypotheses you can test. Consider all the ways seawater can get into the boat. The water is coming in through one of them. Which are connected to the place the water went (the shower pan)? What is the route in each case? Remember that pumps are not seals- water can go backwards through vane and centrifugal pumps.

In the meantime, consider a leave-the-boat checklist, and check frequently until you find this sucker.

Yeah the only source is the head which needs electricity to run (boat was powerless) or backwards through the shower evacuation pluming. Not sure if the stopcock is normally back flow protected somehow. And yes the tub is below the waterline but water would need to get up about 1m - down through the pump and to the water outlet in the tub ... pretty long way and pretty big line ...

[doschhar]

Originally Posted by Rohan

That does sound strange. I assume your head uses raw water from outside? The only possibility that comes to mind is a mechanical/electrical problem that caused the toilet to keep picking up water and overflowing out of the bowl. But I am far from an expert here.

Checked - but pump runs with electricity and boat was powerless. Also bowl was not full of water ... looked normal.

[peghall]

Although sink drain thru-hulls are almost always below waterline on sailboats--and there are always seacocks on them, I've never seen a shower sump discharge thru-hull that was below the waterline even on a sailboat, 'cuz sea water would rise in the discharge line to the boat's waterline unless there's also a seacock on that thru-hull--which would be very unusual--or there is one that's left open except when in use. If the waterline is higher than the shower pan, that would account for the seawater flood in the head.


--Peggie

[doschhar]

Originally Posted by peghall

I've never seen a shower sump discharge thru-hull that was below the waterline even on a sailboat, 'cuz sea water would rise in the discharge line to the boat's waterline unless there's a seacock on that thru-hull, or there is one that's left open except when in use. If the waterline is higher than the shower pan, that would account for the seawater flood in the head.


--Peggie

Well the waterline is higher than the shower pan but not higher than the head. I disconnected the shower sump discharge line after the pump and could suck saltwater back through the system (so there is no back flow protection at the seacock?!). Unfortunately I could not test to suck back water with the pump in between (need additional pipe for that) ...

[peghall]

I don't THINK the head has anything to do with the flooding...it's coming in via the shower sump discharge and overflowing the shower pan. The seacock IS the backflow protection...keeping it closed except when the sump pump is running to empty the shower water should solve your problem.


--Peggie

[doschhar]

Originally Posted by peghall

I don't THINK the head has anything to do with the flooding...it's coming in via the shower sump discharge and overflowing the shower pan. The seacock IS the backflow protection...keeping it closed except when the sump pump is running to empty the shower water should solve your problem.


--Peggie

Yeah I would think so too. It still baffles me is how water can crawl up about 1 meter through a 1 1/2 inch hose, through a loop, back down through the pump and out of the shower pan. Boat was moored at port in good weather conditions.

My guess is that the hose was clogged at the seacock or outlet somehow, not fully just enough to keep the hose full of water after pumping out and starting a very slow flow back through the entire system. The shower pan rim being higher then the waterline (I guess can't really measure) - maybe by design or pure luck stopped the back flow and saved the boat from filling up with water lowering the sump even more and starting a devils circle of eventually sinking my boat ?!

Only explanation I can think of ...

What you think about adding an electric/magnetic seacock that closes automatically if the pump is not used. Would make me sleep much better. Without the pump running there is no reason to keep the cock open anyhow I guess?!

Thanks for reading.

[peghall]

What you think about adding an electric/magnetic seacock that closes automatically if the pump is not used.

I think you're asking if I approve of a device that would absolve you from assuming any hands-on responsibility for the safety of your boat (i.e. remembering to keep the seacock closed). No I don't...if for no other reason than, devices that can be ignored will be until you have to deal with the consequences of their inevitable failure.


Without the pump running there is no reason to keep the cock open anyhow I guess?


Exactly.



--Peggie

[Cadence]

Originally Posted by doschhar

Yeah I would think so too. It still baffles me is how water can crawl up about 1 meter through a 1 1/2 inch hose, through a loop, back down through the pump and out of the shower pan. Boat was moored at port in good weather conditions.

My guess is that the hose was clogged at the seacock or outlet somehow, not fully just enough to keep the hose full of water after pumping out and starting a very slow flow back through the entire system. The shower pan rim being higher then the waterline (I guess can't really measure) - maybe by design or pure luck stopped the back flow and saved the boat from filling up with water lowering the sump even more and starting a devils circle of eventually sinking my boat ?!

Only explanation I can think of ...

What you think about adding an electric/magnetic seacock that closes automatically if the pump is not used. Would make me sleep much better. Without the pump running there is no reason to keep the cock open anyhow I guess?!

Thanks for reading.

A "loop" isn't going to prevent a syphon.

[Cadence]

Originally Posted by Cadence

A "loop" isn't going to prevent a syphon.

I think your damn lucky the edge of then pan was above the water line.

[doschhar]

Originally Posted by peghall

What you think about adding an electric/magnetic seacock that closes automatically if the pump is not used.

I think you're asking if I approve of a device that would absolve you from assuming any hands-on responsibility for the safety of your boat (i.e. remembering to keep the seacock closed). No I don't...if for no other reason than, devices that can be ignored will be until you have to deal with the consequences of their inevitable failure.


Without the pump running there is no reason to keep the cock open anyhow I guess?


Exactly.



--Peggie

Got your point.