head plumbing E38

[Alex]

I am replacing the head and hoses on a 1981 E38. I cannot figure out where the vented loops originally were. The exhisting setup (not original) had none. I would like to have Y valve to overboard or to holding tank. It seems that to get the loop above waterline (especially at any heel, I will need to make new holes in cabnetry, I am not opposed to this, but think that there should be a way to route hoses as they were originally.

-Alex

 

[Loren Beach]

To vent or not to vent

FYI: in 1988 Ericson did not use a vented loop on either the inlet or outlet side of our head plumbing. We always shut off the thruhulls when not aboard, as a precaution.

When underway I check the toilet frequently for evidence of back-filling. (Being over a certain age, I inspect the head rather more regularly than a younger person would, in any case!)

My point, and I do have one... is that your original installation might not have had those loops. Note that these extra lengths of hose and their specialized valving can introduce new (and sometimes messy) failure points into your head plumbing system.
It's a "generally good idea", but not... unreservedly.

My .02 worth,
Loren in PDX

 

[Frank Langer]

Loren,
I was interested to hear that even later Ericsons did not add vent loops for the head plumbing. I have always read that vent loops are an essential safety precaution to avoid backfilling in both the intake and the discharge hose.
In my own experience, where I also close the seacocks before leaving the boat for extended periods, I did run into a potentially serious problem. While on the boat for the weekend, with seacocks open, I made a quick trip to the chandlery for a part that is normally readily available, but needed to go to several places as they were out of stock. On my return two hours later (yes, I have been known to browse at the chandlery ), the head had overflowed and created about 2 inches of water on the floor, almost overflowing into the main cabin (clean seawater, fortunately). One of the valves in the head itself was corroded, so it was no longer operating properly, and sucking water in through the intake hose. While I was fortunate to catch it before it became a larger problem, if this had been overnight, my bilge pump would have been very active by morning! :0305_alar
Given my experience, I am now convinced that vent hoses are an important precaution.

Frank.

 

[Alex]

vented loop

I was trying to clear a clogged Y valve and had operated the head, also in poor repair. I left the head valve (wilcox headmaster) in "flush", and the intake seacock open (accidently) while I left to get lunch. I returned an hour later to find the bowl slowly filling and within an inch of overflowing. Seems the valves on head were very corroded, hence the replacement. I will be installing a loop on the intake side, it may end up being in the open behind the head, seems to be the least cluttered, but a little unsightly. This will be a liveaboard, and the head is used often.

-Alex

 

[Glyn Judson]

Head overflow and potential boat sinking, yikes!!

Alex, The owner of E31 hull #33 and I had the exact same Groco head installation except that I fitted a vented loop as you speak of and he didn't. My loop is a 3/4" bronze Groco on the forward bulkhead behind and above my Groco K-H head. As it's on the intake side, water can only be pulled past it if the vent hole is covered with an index finger. The loop is at about chest height, almost on the center line of the boat and normally covered by a bath towel on a hook hanging over it. The beauty of this method of loop use is that as soon as the vent hole is released, water in the intake hose returns to its safe lever way below the loop. My Groco bowl is about 1/4 of an inch above the waterline. The same Groco K-H head in hull #33 was about 1/4 inch below the waterline and as happed to you but worse, the owner came back to the boat from a quick trip to West Marine to find the cabin sole awash in 2 to 3 inches of water. This happened to him twice in two weeks so he resolved not to rely upon his memory to close the raw water seacock. So he and I fitted that same loop in his boat which gave him great peace of mind. Glyn Judson E31 hull #55, Marina del Rey, CA

 

[wheelerwbrian]

My 88 E38 has a vented loop, either up behind the sink or up in the cabinet (I think its the sink) -- I can't remember which. In any case, we close the head seacock and the sink seacock, since both can go under the waterline when heeled to starboard, but usually leave it open when we're aboard at anchor or docked.

 

[rwthomas1]

The head intake hose, 1" dia, has a loop that peaks just under the lavatory sink countertop before it heads back down to the intake on the Raritan head. No vent in the loop. There is no Y valve in my system. The head dumps into the holding tank. There are two outlets to the holding tank. One leads up to the deck pumpout fitting. The other leads up to a Whale manual pump installed in the bulkhead just behind the head. The Whale pump dumps the holding tank contents overboard through a 1.5" thru-hull. This thru-hull is attached to a 90* bronze fitting and then a ball valve. It is the only non-flanged seacock on the boat. There is simply no room in the head cabinetry to install a proper flanged 1.5" seacock. I am okay with this since there is no way the thru-hull, etc. would ever be subjected to serious side loads. The 1.5" discharge hose leads up the inside of the hull to just above the waterline and then back to the Whale pump. We never leave seacocks open when we are not on the boat. There has never been any problem with this setup siphoning, backflowing etc. The seacocks are closed when sailing. Check the pic out. RT

 

[Frank Langer]

Rob, although closing the seacocks when away from the boat or under sail is a good precaution, it seems to me that there is still the potential for your intake hose to act as a siphon if you leave the seacock open while at the dock. In my limited understanding, the only way to avoid that is to install a vent of some kind on the intake hose. Am I missing something?
Frank.

 

[Alex]

Thanks Rob,

That is similar to my setup, without the whale pump. I installed the head to holding tank direct without a Y valve. I closed and capped the 1.5" seacock, I will install a whale pump and second discharge line from the holding tank at a later date.

Still not sure what to do with the intake. My lavatory cabinet has a shelf below the sink, so the loop could not get above waterline (without drilling holes). Even above waterline without a vent it could siphon, and with a vent no water could be pulled by the head. I think the vented loop should be between head pump and bowl, this puts it in view. I may put a shutoff inline between head pump/bowl, as a second safety.
-Alex

 

[rwthomas1]

Alex,
I should have noted that the intake hose you see in the pic, the lower right hose, feeds the head intake. It does in fact pass through the shelf above it then it makes a 180* turn and returns down through another hole just a few inches away from the first. The 180* turn is touching the bottom of the countertop.

Frank,
You may be right. I have no idea. Is there supposed to be a vented loop on the top of the 180* turn in the intake hose? How would this work with the hand pump trying to suck water in? Wouldn't this leak and prevent suction? I don't know..... When I replaced all the seacocks I just replaced the existing hoses with new in the same configuration. Maybe it doesn't siphon due to the one way valves in the head? Or am I just lucky? We are sort of seacock phobic. They are closed far more than they are open. RT

 

[Frank Langer]

Rob, I think we are all still trying to figure this out. Maybe someone more knowledgable will chime in to provide some answers. All the books seem to say that whenever a hose originates below the waterline, for either intake or discharge, it needs to be looped and vented. I understand your concern that this would interfere with suction of the pump; I have similarly wondered if this wouldn't lead to leaking out of the vent hole, even if the pump were strong enough to overcome the vent leak.
In the meantime, I think it makes sense to keep seacocks closed whenever reasonably possible, and to monitor regularly when they are open. But even so, one hears of boats sinking; in my own case, my head/toilet overflowed due to siphoning and a faulty valve in the head intake--fortunately I returned to the boat before it caused any damage, but I did have a full head and two inches of water on the floor in the head, ready to spill over the sill into the main cabin (after only being away two hours).
It's because of this experience, and wanting to ensure that I have taken all reasonable precautions, that I am interested in this issue.
Frank.

 

[ted_reshetiloff]

Vent on a suction line (Intake for the head) will suck air and not draw water, or will draw very little water. Do you have a vent on the intake for your engine cooling? Path of least resistance is for air not water if you put a vent on this line. Close the seacock when not aboard and maintain your head so it does not leak when aboard.

I have a big sign reminding folks to leave the head valve in the DRY setting when leaving the head. It does not leak and will not flood the boat unless someone leaves the valve on the head open. I still close the seacock also when not aboard.

 

[Frank Langer]

Ted, my boat began to flood (though I caught it in time) due to a faulty intake valve in the head itself--no warning signs, and could only spot it when I actually took the head apart to inspect the valve. While most of us close seacocks on leaving the boat for longer periods, I would guess that many of us leave the seacocks open when we are down the dock at another boat for a drink in the evening, or to run a quick errand, etc. Even though I had the head valve on "dry", the fact that it was faulty was enough to find 2" of water on the head floor after being away only two hours. I now close the seacock every time I leave the boat, even for an hour, but I suspect many don't do so.
Frank.

 

[Randy Rutledge]

What do you think?

Would an ant siphon valve work to prevent this??? Fuel lines have them and the fuel pump will overcome the valve. The valve would have to overcome the head pressure from the depth under the water line or would it be a balance if the valve was at the top of a loop??? The head intake pump should overcome a reasonable amount of valve pressure.

 

[Alex]

Head Suction

The Head will not pull suction if there is a vent between seacock and pump, but a vented loop between head pump and bowl will prevent siphoning. The problem then is that the loop is in plain view, and unsightly.
-Alex

 

[ted_reshetiloff]

Alex has it here. The siphon breaker needs to be on the pressure side not the suction. I have never seen a siphon break valve on a fuel pump and would surmise you would have a lot of air in your fuel if you got any fuel at all. A simple test. Take a manual bilge pump INTAKE side and attach some hose with a siphon break. Try pumping water through this settup. You might get some but you will get mostly air.