Missing Vented Loops?

[71Percent]

Looking at a 20 year old Jeanneau with what appears to be new 1.5" white sanitation hose (the cheap sort). Found a diagram in the manual which looks exactly like what's in the head, but after reading Peggy Hall's book I noticed there is not a single true vented loop in the system - is this normal or someone taking a short cut?

[Uncle Bob]

Originally Posted by 71Percent

Looking at a 20 year old Jeanneau with what appears to be new 1.5" white sanitation hose (the cheap sort). Found a diagram in the manual which looks exactly like what's in the head, but after reading Peggy Hall's book I noticed there is not a single true vented loop in the system - is this normal or someone taking a short cut?

Looks about right to me, toilet output goes to top of tank, which is above w/l, vent goes to top of tank, deck pump out connection from top of tank and gravity overboard discharge from bottom of tank.
The only place that you could put a vented loop is in the toilet discharge line at the top of the tank which is essentially not needed, the vent performing that function. The only time you may encounter a problem is when the tank is absolutely full. That design cannot syphon because everything is above the waterline.

[peghall]

A vented loop isn't needed in the toilet discharge line that only goes into a tank, nor in the tank discharge line if the tank is entirely above the waterline.



However, one IS needed in the toilet's flush water INTAKE...it belongs between the pump and the bowl and needs to be at least 6-8" above waterline AT ANY ANGLE OF HEEL, which on most sailboats puts it 2-3 FEET above the bowl. You'll replace short piece of hose the toilet mfr used to connect the pump to the back of the bowl with enough to put the loop where it belongs.

--Peggie

[71Percent]

Much appreciated!

[Chrisatlantic]

What would the function of the vent for the flush intake be? Wouldn’t that just introduce air when you are flushing the toilet?

[Bill Seal]

it belongs between the pump and the bowl

I assume the vented loop has a check valve to stop it from squirting sea water out while pumping.
Or maybe not

[Cheechako]

Originally Posted by Chrisatlantic

What would the function of the vent for the flush intake be? Wouldn’t that just introduce air when you are flushing the toilet?

Not a vent , a siphon break or loop. When pumping, the suction pulls the vent valve closed.
It keeps from siphoning the boat full if something fails. If the intake is below the waterline and the bowl is below the waterline.

[Bill Seal]

If, as Peggy recommends, the syphon break is between the pump and the bowl, there will be no SUCTION, only pressure.

[mvweebles]

Originally Posted by peghall

A vented loop isn't needed in the toilet discharge line that only goes into a tank, nor in the tank discharge line if the tank is entirely above the waterline.



However, one IS needed in the toilet's flush water INTAKE...it belongs between the pump and the bowl and needs to be at least 6-8" above waterline AT ANY ANGLE OF HEEL, which on most sailboats puts it 2-3 FEET above the bowl. You'll replace short piece of hose the toilet mfr used to connect the pump to the back of the bowl with enough to put the loop where it belongs.

--Peggie

Are we talking the pump on the toilet that pumps water for flushing? How do you route a vented loop there? Isn't it usually an integral path? I once had a Groco Model K and would have loved to do this but couldn't figure out how. I believe jabsco makes a solenoid actuated vent that closes when actuated so you can place between the thru-hull and pump, but I couldn't figure out an elegant option.

How is this different from any other seawater head? How does the holding tank being above waterline change the requiremnt of thr intake?

Peter

Peter

[Cheechako]

Originally Posted by mvweebles

Are we talking the pump on the toilet that pumps water for flushing? How do you route a vented loop there? Isn't it usually an integral path? I once had a Groco Model K and would have loved to do this but couldn't figure out how. I believe jabsco makes a solenoid actuated vent that closes when actuated so you can place between the thru-hull and pump, but I couldn't figure out an elegant option.

How is this different from any other seawater head? How does the holding tank being above waterline change the requiremnt of thr intake?

Peter

Peter

You route the hose between the toilet pump and the bowl up to a loop instead of direct to the bowl.
I have had boats where it is between the seacock and the pump and that works also if it's an easier install. However one I had felt like it was sucking bubbles, although it worked. So I suppose it depends on how well the vented loop valve works.

[peghall]

Are we talking the pump on the toilet that pumps water for flushing?

Yes. If it's a manual toilet (except for those like the Model K and the W-C Skipper), the vented loop needs to be between the pump and the bowl...see Figure 1 on page 3 of the owners manual Jabsco Twist 'n' Lock Manual Toilets (it's the same for all manual toilets). It needs to be at least 6-8" above waterline AT ANY ANGLE of HEEL, not just when the boat is at rest, which on most sailboats puts it 2-3' above the bowl.This requires replacing the short piece of hose the toilet mfrs use to connect the pump to the back of the bowl with 2 pieces of hose long enough to mount it that high.

It should be installed in the same location on electric toilets that have a bowl bolted to the pump/motor assembly. All china "thrones" need a solenoid valve with vented loop installed in the flush water intake line.

How does the holding tank being above waterline change the requiremnt of thr intake?

Neither the location of the holding tank nor anything else to do with it has anything to do with toilet flush water intake. Nor is a vented loop needed in the toilet line if the toilet only flushes into the tank, does not flush directly overboard.

--Peggie

[mvweebles]

Originally Posted by peghall

Are we talking the pump on the toilet that pumps water for flushing?

Yes. If it's a manual toilet (except for those like the Model K and the W-C Skipper), the vented loop needs to be between the pump and the bowl...see Figure 1 on page 3 of the owners manual Jabsco Twist 'n' Lock Manual Toilets (it's the same for all manual toilets). It needs to be at least 6-8" above waterline AT ANY ANGLE of HEEL, not just when the boat is at rest, which on most sailboats puts it 2-3' above the bowl.This requires replacing the short piece of hose the toilet mfrs use to connect the pump to the back of the bowl with 2 pieces of hose long enough to mount it that high.

It should be installed in the same location on electric toilets that have a bowl bolted to the pump/motor assembly. All china "thrones" need a solenoid valve with vented loop installed in the flush water intake line.

--Peggie

If pump is on suction side of vented loop, assume something like this is needed

https://www.amazon.com/s?k=Jabsco+37...f=nb_sb_noss_2

Not the best reviews.....lot to be said for a modern hi-quality freshwater head such as the Raritan Marine Elegance I suppose.

Peter

[peghall]

Raritan does not use Jabsco solenoids nor any other Jabsco parts in their Marine Elegance or any other Raritan toilets.


--Peggie

[mvweebles]

Originally Posted by peghall

Raritan does not use Jabsco solenoids nor any other Jabsco parts in their Marine Elegance or any other Raritan toilets.


--Peggie

Are there other options for a solenoid actuated vented loop? When I was looking, the jabsco was the only one I could find.

The Elegance has a raw water option (I believe). If the head is mounted below waterline, how is the intake vented?

Peter

[peghall]

It does have a raw water option that requires adding a remote intake pump. The ME "Installation, Operation and Maintenance Instructions" (aka "owners manual") sayeth that "Sea Water Models installed below the waterline MUST have a vented loop installed between the intake pump and the toilet bowl." Raritan Marine Elegance Owners Manual


--Peggie