Jabsco Head

[captden]

Thanks to all who answered I ended up buying a new pump and installed now it works great, you guys were right it was the easiest fix just took ten min. to do. Thanks again
captden

[HopCar]

You're right Zeehag, if you remember to turn the lever to dry bowl every time, you don't need the vented loop in the small hose. It's sort of a belt and suspenders thing. If you or a guest forgets to set the lever, the vent could save you from having to clean up a big mess. You are also correct that if you just install it in the intake hose as scpct appears to have done, it will make it hard to pump. Actually in that installation, all he would need to do is cover the vacuum breaker with a finger tip while he pumps with the other hand. This is similar to what hylyte has done. The other way is to put the loop in the hose that connects the pump to the back of the toilet bowl. That way you don't need to cover the vent. Hylytes solution is a little more elagant as his plumbing is hidden. I don't think I've ever heard of a boat sinking because of unwanted flow through the toilet intake, after all your bilge pump should be able to handle it. I have heard of people having to clean up a lot of water because of it. The discharge is another matter. That's an 1-1/2" hose and a lot of water could come through it.

[sctpc]

Originally Posted by zeehag

fwiw--you STILL have to remember to turn the lever.... one lever or another doesnt matter. the simplest and easiest installation is the one i read from the jabsco manual-- no vented loop on the skinny hose. only on the out(fat) hose.

Ok the pro has done it wrong (another k to try and fix it) It all started when I did nearly sink due to the siphon over flowing. So anyway I did put my finger over the top holes and still got no suction, I pored in a bucket of water with the toilet still in fill mode and it pumped out the water and still not suction,
1. could the small suction hose be to high out of the water?
2. could I try and prime the toilet pump some other way
3. get a new toilet
4. take the small hose off and connect it strait back to to the pump, problem back to start.
5. you have a better idea

[HopCar]

sctpc it really sounds like air is getting in on the suction side. Did it work before the vented loops were installed? If it did, start at the seacock and tighten all of the hose clamps and be sure the vacuum breaker is screwed tightly to the loop. Gently tighten all the screws on the pump. If it didn't work well before the vented loops were installed, rebuild or replace the pump. Don't worry about covering the hole on the big loop. It doesn't have any effect on your current problem.

[sctpc]

[QUOTE=HopCar;720470] Did it work before the vented loops were installed? yes the head worked perfectly it was simply the thought of coming to see my boat under water due to the fact the seacock could not tell if it was off or on that made me replace them.

we have 50k wind in melbourne today so ill have to wait till next week to get out to my lady and ill check the clamps then.

The big loop squirts the sea water out the top when I pump so id hate to use the head anyway.

[HopCar]

You've got a problem with the big loop. It shouldn't squirt water. Take apart the vent and see if you can spot the problem. It's supposed to let air into the loop and nothing out. Yours look like Forespar Loops but all the Forespar loops I've seen are black. Are yours painted? Here is a link to the Forespar website with lots of good information on installing and maintaining vented loops: Boat Marine Plumbing Vented Loop Thru Hull
Scroll down, watch the video, read the instructions and teck tips. Note that they suggest that the loops be mounted on the centerline of the boat. They also recommend that the loop on the small intake hose be mounted between the pump and the bowl.

[peghall]

I dunno where you got THAT idea, Karen...'cuz EVERY manual toilet mfr recommends a vented loop in the intake if the toilet is at or below the waterline...NOT in the line between the thru-hull and the pump, but between the pump and the bowl. See the drawings in the installation instructions:

Jabsco: Jabsco manual toilet instructions

Raritan PH II: http://www.raritaneng.com/pdf_files/ph_II/L04v0505.pdf

Raritan Compact: http://www.raritaneng.com/pdf_files/...actIIv0502.pdf

Thetford Comfort Mate: Only way to get to the manual for this toilet is to click on the link to download it from this page (intake plumbing instructions with drawing are on page 14): ComfortMate Manual (PDF)

I could post a bunch more, but I think that's enough to prove that a vented loop DOES belong in the "skinny hose."

[zeehag]

funny how mine never ever had a vented loop in the skinny hose-- i have owned a few boats since 1990 and never had a problem with head-- never ever had a vented loop in the inlet hose. only outlet hose.

[svHyLyte]

Originally Posted by zeehag

funny how mine never ever had a vented loop in the skinny hose-- i have owned a few boats since 1990 and never had a problem with head-- never ever had a vented loop in the inlet hose. only outlet hose.

Because things have been done improperly aboard some yachts is not affirmative evidence that they should be done improperly. Sometimes one can "get by", other times not--as in the case of our slip neighbor, a Jeneau 42, who arrived at his boat one day last year to discover water up to the level of his seat-cushions. (His batteries had evidently given up the ghost supporting the automatic bilge pump over the prior week.) Twenty+grand in repairs later, he now has a $15 USD anti-siphon loop on his head.

[nigel1]

Originally Posted by svHyLyte

Because things have been done improperly aboard some yachts is not affirmative evidence that they should be done improperly. Sometimes one can "get by", other times not--as in the case of our slip neighbor, a Jeneau 42, who arrived at his boat one day last year to discover water up to the level of his seat-cushions. (His batteries had evidently given up the ghost supporting the automatic bilge pump over the prior week.) Twenty+grand in repairs later, he now has a $15 USD anti-siphon loop on his head.

Now there's a good incentive to close the skin valves when leaving the boat.

[zeehag]

a vented loop in the intake defeats the purpose of the intake-- prevents intake of water to the bowl. a vented loop on the outflow is proper and prevents the inflow of water when it not welcome.
i have never sailed or been onboard a boat with a vented loop in the intake. not evr. nor willi own a boat with a vented intake hose. i WANT to wet pump my bowl. sorry. is fact as well as common sense.
sorry, peggy, my instructions never stated make a vent in the incoming loop. only in the outgoing loop

anyone coming aboard my boat who FORGETS to turn the lever is not invited back to my boat sinking party...LOL

[svHyLyte]

Originally Posted by zeehag

a vented loop in the intake defeats the purpose of the intake-- prevents intake of water to the bowl. a vented loop on the outflow is proper and prevents the inflow of water when it not welcome.
i have never sailed or been onboard a boat with a vented loop in the intake. not evr. nor willi own a boat with a vented intake hose. i WANT to wet pump my bowl. sorry. is fact as well as common sense.
sorry, peggy, my instructions never stated make a vent in the incoming loop. only in the outgoing loop

Oy Veh! Round'n round'nround we go....

[HopCar]

Zeehag, you're not understanding that the small vented loop does not go in the suction line between the pump and the seacock, it goes in the pressure line between the pump and the bowl. You don't really need it if your toilet is always above the waterline or if you always switch the lever to dry bowl and if that silly little valve in the toilet doesn't fail.

[nylajo]

Originally Posted by zeehag

a vented loop in the intake defeats the purpose of the intake-- prevents intake of water to the bowl. a vented loop on the outflow is proper and prevents the inflow of water when it not welcome.
i have never sailed or been onboard a boat with a vented loop in the intake. not evr. nor willi own a boat with a vented intake hose. i WANT to wet pump my bowl. sorry. is fact as well as common sense.
sorry, peggy, my instructions never stated make a vent in the incoming loop. only in the outgoing loop

anyone coming aboard my boat who FORGETS to turn the lever is not invited back to my boat sinking party...LOL

Once the water has passed through the pump it is no longer an incoming hose, it is now a pressure hose and the vented loop will work as it should.

[peghall]

Maybe I can explain it so she'll finally get it...

Karen, you're correct that vented loop in the "skinny hose" interferes with the toilets ability to prime and pull in water. That's why the vented loop can't go in the line between the thru-hull and the pump...it has to go between the pump and the bowl. Most marine toilets come from the factory with a short "skinny hose" coming off the top of the pump that runs to a connection on the back of the bowl. That hose has to be replaced with new "skinny hose" that's long enough to put the vented loop high enough to keep it at least 6-8" above waterline at any angle of heel, same as a vented loop in any other line going to a below-waterline thru-hull.

Marine toilets only PULL water in as far as the pump... so if there's a vented loop in the line between the through hull and the pump, pumping the toilet would pull air into the line...you have that much correct. But what you're missing is that the pump then PUSHES the water to the bowl...and a vented loop does not interfere in any way with water being pushed through it. If you look at the drawings in all the installation instructions I posted, you'll see that none of 'em show the vented loop between the thru-hull and the pump...that it's ALWAYS between the pump and the bowl. If you don't have one, you really need to install one...and be sure there's an air valve in the nipple so it can't squirt!