We're replacing the toilet (bought the Raritan PHII base to use with existing bowl) and the waste hoses in our 1983 C36. The PO had a vented loop running up the wall in the head after the toilet and before going to a Y valve--1 line to the holding tank, 1 to the discharge thru hull.
I'm a bit confused/unsure of what is best/necessary. We have 2 thru-hulls for waste: 1 from the macerator and the other for direct discharge (when legal to do so).
The plumbing diagram for the Raritan (and some other online articles) emphasizes the need for a vented loop after the toilet when the toilet is below the waterline. The C36 manual for the plumbing of the head doesn't appear to show one.
I plan to reinstall hoses in the same configuration but question if the vented loop is needed? Is it possibly necessary for the instances when the Y valve is sending discharge directly thru the hull? Would it not be necessary if we plumbed straight to the holding tank?
Doug
I believe our toilet seats are very close to the waterline. If you have a Y-valve that is selected to "sea" and if the seacock is open, the loop prevents flooding when heeled and the vent may prevent flooding from siphon.
For boats that don't have a Y-valve and simply dump into the holding tank, a loop on the discharge line is not fit by the factory.
Nick Caballero
Retired C36/375IA Mk II Technical Editor
Thanks, Nick. I continue to read up on proper design and function (especially Peggy Hall's contributions on sailboatowners.com), and it seems that there is a valid purpose for that loop from the toilet to the Y. So we're going to replumb it.
The other thing I'm now curious about is a vented loop from the line to bring sea water in to flush with. The existing line goes directly from the thru hull to the toilet. I'm seeing comments about having a vented loop for that as well.
There is a vented loop back in there, but it's currently plumbed for pumping the shower bilge. That doesn't make sense.
I'm wondering if someone previously didn't connect the hoses correctly during a replumb?
Hey Doug. A vented loop on the intake is recommended for toilets that are close to or below the water line. Keep in mind that the proper place for this vented loop is not in the section on hose that runs from the seacock to the inlet valve, but rather in the section of hose that runs between the inlet valve and the toilet bowl. This is the way the MKII is factory done.
Nick Caballero
Retired C36/375IA Mk II Technical Editor
Hi Nick
my 2006 C36 MkII #2282 was not fitted with a 1.5" waste Vent.
The 1.5" waste hose runs directly to the Holding Tank.
In the early days of next week, I will commence correcting that.
Can you tell me if the Vent is positioned above the top shelf in the cupboard behind the toilet?
Thanks
Bruce Stanley/Sydney Australia
Hi Gary
thanks for that height info.
It seems best practice to put it as high up as pos.
Rgds
BruceS
NEW Question re 1.5" Vent Head Lo0op
can anyone tell me:
1> which side of the Cabinet does the 1.5" hose entre?
2> which side wall is the Vent Loop secured?
Thanks
Bruce Stanley / Sydney
Bruce,
It is located in that cabinet and I believe it is just above the top shelf, but not exactly sure. The 1st shelf would be above the waterline as well so that would be high enough.
Gary Bain
S/V "Gone With The Wind"
Catalina 36', Hull #: 1056, Year: 1990, Engine: M-35
Standard Rig
Moored: Boothbay Harbor, Maine
Home: Auburn, Maine