Heads - no anti syphon valve loop

[Sitesurfer]

Hi folks, I'm about to follow in Yngmars footsteps and install Tru-Design sea cocks and thru-hulls.

Bavaria 36 - 2002 - Owners cabin version (2 cabins with aft heads)

The waste pipe from the head (outlet) goes directly to the sea cock without a vented loop in - is this normal?
The inlet ditto, no loop in it.

If they are fitted normally - I'd really REALLY appreciate a shot of how and where, but first - below may change that.

I currrently don't have a holding tank and whilst a while back someone sent me an image of their holding tank I still have one little question about that.

I'm trying to work out from the Bavaria diagram where the holding tank should go from when fitted as new, the plan suggest that it goes in a the small gap inside the hanging locker - but it seems rather a small space, failing that it could be the bulkhead in the lazarette. Anyone got a photo of theirs to hand? It may be that I have to rip a wall down to get it in (but hoping not!).

My boat:


And the manual for my boat which is not the same as the diagram which shows the holding tank position.
(see below)

Note: am looking at a Tek Tanks solution, this would negate the need for the vented loop as it would be within the circuit - but might not be going to happen for 12 months so the first question is still valid.

[Yngmar]

The waste pipe from the head (outlet) goes directly to the sea cock without a vented loop in - is this normal?
The inlet ditto, no loop in it.

That's how it is on our boat, no problems with it. Both hoses are looped (not vented, just looped) upwards well above the waterline before coming back down, but no siphon breaks in them.

We have a holding tank on our 40 Ocean, behind the (removable) shower wall, in the curvature of the topsides. There's a Whale 3-way valve in the toilet outlet, which lets us choose whether the toilet output goes straight to sea or into the top of the holding tank. The holding tank is gravity drained, with a separate outlet seacock. This system works very well, we never had any problems with it (after initial cleanup of massive calcium deposits from previous owners).

I've just replaced the diverter valve (after 18 years it started to leak - acceptable service life). Was pleased to see that with our strict 30 pumps regime (calculated from hose length), we had zero calcium deposits in any of the three hoses connecting to the valve.

When we open the tank seacock to empty the tank, we always flush a large amount of water through, and looking in our wake that seems to empty the solids which don't always come out without the extra flushing. Doing this, it always empties completely.

Toilet paper obviously never goes into the toilet, but into a separate bin bag (with airtight lid).

This setup and usage has been working flawlessly for us for two years now. The only issue we had was prior to the 30 pump flush regime from calcium deposits, never any since, and some normal wear maintenance on the pump and now the diverter valve. Avoid toilet dramas ;-)

[Sitesurfer]

Thanks for that, it would appear that my installation is incorrect then as there is no loop upwards at all, the pipe just goes along the floor direct to the sea cock.

[Salty]

.
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That's how it is on our boat, no problems with it. Both hoses are looped (not vented, just looped) upwards well above the waterline before coming back down, but no siphon breaks in them.
.

I have a three cabin B36(2002) and with same arrangement as Yngmar, looped but not vented hoses. Previous boat (not Bavaria) was the same arrangement, looped but not vented.

There is a holding tank installed, but not connected - maybe a job for the winter.

[Sitesurfer]

Looks like my boat despite being same era as yours is very different, smaller Genoa, no loop in heads piping etc. How odd.

Beginning to wonder if PO has done a load of fiddling.

The only place the outlet hose could loop would be within the sink cabinet and I’m not convinced that there’s enough vertical room to get it above the waterline, needs more measuring clearly and more googling for images.

[Symphony]

There does not need to be a loop or vent in the inlet, but should be at least a loop in the outlet. Vent is not normally needed. With regards to the holding tank, the original (optional) system may well have been a pumped system with the holding tank under the saloon bunk - it was on my old 37 of similar vintage. I specifically did not order it as it is expensive and gives trouble, with several metres of pipe permanently full of sewage and reliant on a pump to empty. I fitted a gravity tank in the locker in the loo compartment. Bit of a tight fit and meant moving the water valves and pump a bit, but we managed a tank of 50 litres. Th outlet goes from the loo pump to an inlet on the bottom of the tank with a stack tube inside. The outlet to the original seacock is at the other end with the deck pumpout immediately above it to allow rodding if necessary. An inspection hatch was fitted on the top. The tank therefore acts as a loop above the waterline as all output goes through it and if you want to hold output just close the seacock. Essentially the same as the system fitted to current boats. Simple and works well.  An alternative may be to fit the tank in the cockpit locker on the bulkhead as is common on other types of boat with the same layout. This could be simpler to do and give you potentially a larger tank at the expense of some locker space.

Tek Tanks should be able to make one for you and may already have a design prepared for your model boat.

[Sitesurfer]

I'm just finding it really odd that the owners manual diagram above (which is the same as the one I possess on the boat) is so inaccurate with regard to the shape of the heads. Having said that - the galley is different to the plan and so is the table in the centre of the saloon. I'm wondering whether the diagram is for a different size model.

[Jeff Jones]

Hi - I installed a Vetus 60L (ww60w) black water tank on the bulkhead wall in the lazerette backing onto the handling locker in the head. it was a nice fit on my Bav34 which I understand may be the same hull as your 36. if your lucky I had some holes already drill for hose access.

[Sitesurfer]

Can I ask, that wall is exactly the same as mine I suspect - you placed the tank on the locker side? Bavaria seems to have left plenty of limber holes for pipes. I only ask as I suspect that's a pre-install image - do you have a post-install one for comparison? I'm very curious.

[Symphony]

One of the advantages of having the tank in the locker is that you can probably have the waste from the toilet going into the top of the tank which avoids an internal tube and the outlet immediately below the inspection hatch  There may also be room to fit a valve on the outlet so you don't need to use the seacock for the isolator when using the tank to hold waste. That means the hose from the tank to the seacock is not full of waste.

Worth looking on the Tek Tanks site as there is good information there on design and layout of holding tank systems.

[MarkTheBike]

Can I ask, that wall is exactly the same as mine I suspect - you placed the tank on the locker side? Bavaria seems to have left plenty of limber holes for pipes. I only ask as I suspect that's a pre-install image - do you have a post-install one for comparison? I'm very curious.

Hi Sitesurfer

I've got the same boat as JeffJones, with a tank fitted to that bulkhead. I'll be down there on Thursday so will photo and post if that's soon enough...

Cheers, M

[Impavidus]

Hi all. Just to add my two penneth. Both our bavaria's had direct hoses with high loops and no anti syphon vents. I questioned this directly with bavaria who said "We advise that these sea cocks are closed before going to sea and place advisory notice in the heads. If you have a holding tank this is vented and basically  has a vented loop via the heads breather tube that will prevent syphoning in heavy seas. The heads inlet on both our Bavaria's had no anti siphon valve. This was a problem on a really rough channel crossing on our 32, when the side decks were constantly under water. The heads inlet whent syphonic and let raw water into the heads. The shower drain pump coped but we then closed it off before setting sail as the sticker in english and german advised!

We have just fitted an electric toilet on Impavidus the supply hose now has a vented loop up high. In really rough weather close all your sea cocks except the raw water inlet to the engine .....     

[Sitesurfer]

Thanks all, I suspect that at some stage the PO has replaced the sanitary hose and decided to avoid the loop..
I will be replacing it all along with the seacocks in the next couple weeks!

I'm in no rush for the photo, it's purely for research and gratefully received.

Although I am curious where the high loops actually are - the sink cabinet doesn't seem like it has enough height to accommodate the loop above the waterline.

[Sitesurfer]

Ok.... so I’m officially a numpty.
I just arrived at the boat and thought “let’s check that loop” ... and wouldn’t you know I have a dirty great loop in the hoses! I literally never clocked that before today.

I take back all comments about PO.