Jabsco Head

[Seahunter]

If the bowl is higher than the WL there's no way for water to siphon into the bowl, whether or not the "switch" is on or off. If below the WL, it will only fill to the WL level. This is why most head fixtures are mounted on a pedestal raising them above or close to the WL. Regardless, the anti-siphon valve should always be located higher than the WL is expected to be or to get.
If you have a holding tank without or a faulty existing anti-siphon valve on the flush line and you have a faulty joker valve at the head fixture (a common problem); you'll end up with a nasty surprise. Using a head lubricant every once in a while (or Canola oil) will keep the pump parts and joker valve in decent condition. Checking the anti-siphon valves and tank vents at least every 6 months on the west coast or seasonally on the east coast will prevent the nasties and at minimal, reduce "that" odor.

[peghall]

If the bowl is higher than the WL there's no way for water to siphon into the bowl, whether or not the "switch" is on or off. If below the WL, it will only fill to the WL level.

On a sailboat the waterline can change as much as a foot or more as the boat heels, putting a toilet that's AT the waterline when the boat's at rest waaay below the waterline while undersay...which can make things verrrry interesting if the boat stays on that tack for very long.

Checking the anti-siphon valves and tank vents at least every 6 months on the west coast or seasonally on the east coast will prevent the nasties and at minimal, reduce "that" odor.

Only "seasonally" or "every six months???" Holding tank vents should be backflushed EVERY time the boat is washed and/or pumped out if you want to keep the vent open. I'm sure there must be the occasionally "faulty" joker valve, but I've never seen one. I have seen zillions of worn out jokers valves, though...and nothing can prevent that. They only last a year or two at most.

Most people think a joker valve's only function is to prevent backflow, but it's actually THE most important degradable/replaceable part in a manual pump. Without it, it would impossible to flush the toilet. So if you want to keep a toilet working anywhere near spec, the joker valve should be replaced annually as preventive maintenance.

Btw...why should it matter whether you're on the east or west coast?

[nylajo]

"Btw...why should it matter whether you're on the east or west coast? "



I must say that had me baffled also.

[Seahunter]

peghall, no matter what you think should be done every time the system's flushed; it's almost NEVER done. My suggested timeline is for those that have NO clue. "the anti-siphon valve should always be located higher than the WL is expected to be or to get" covers "On a sailboat the waterline can change as much as a foot or more as the boat heels....".
As a live-aboard, expect to change the joker valve every 5 -6 months. As for east and west coasts; on the east coast most boats are winterized for the season and sanitary systems should at minimal be inspected and repaired at this time. On the west coast as systems are rarely even looked at until there's a problem (because it never freezes), there's a significant difference between the obvious and the "oh crap!".

[Jacana]

Originally Posted by HopCar

It would help to know the model of the toilet. I think HyLyte is on the right track. Take a look at the wet bowl / dry bowl lever and valve assembly. It could be letting air from the rim of the bowl back into the intake side of the piston. If air is getting in, it will never pump water and it wouldn't affect the discharge side. This is a very common problem. Next time I wouldn't mess with trying to rebuild it. You can buy a whole new pump assembly for the newer Jabsco manual toilets for about $56.00. Two hose clamps, four screws, less than ten minutes and you've got a new toilet.

Where can I buy Jabsco pump assembly for $56 my local price is $189 for pump complete or a complete new Mk111 Jabsco toilet for $199.

[HopCar]

Jacana, this is the pump assembly I was refering to.
Jabsco Toilet Pump - 29040-3000
Seahunter, What are these terms you used, "winterized" and "freeze"?
HopCar, Miami Florida

[peghall]

As for east and west coasts; on the east coast most boats are winterized for the season...

Except for all the boats in North and South Carolina, Georgia, Florida or the the Gulf of Mexico. You apparently are not among the few people who know that more than 50% of registered boats in the US are on INLAND lakes and rivers, most of which are far enough south to permit 12 month boating. I was in Atlanta...never winterized in 26 years.

[sctpc]

well two months later I got the marina to look at it and they say it was air in the line, and the big vent is not working so they will order a new one.

[peghall]

WHAT "big vent?" Vented loop??? Why would that need replacing? It may need a new air valve, or may even have installed in the wrong place, but it doesn't make sense to replace a piece of curved PVC.

"Air in the line" as a diagnosis doesn't make much sense either... That simply means the pump won't prime, but doesn't explain why. They may have gotten it to prime, but it's gonna lose prime again--as all toilets do when they sit--and you'll be right back where you started.

Marinas usually have pretty good engine mechanics, but rarely is there anyone who has a clue about how marine toilets actually work. You're gonna end up paying 'em enough to buy 2 new GOOD toilets to try this and that and THEN end up buyng a new toilet anyway.

[sctpc]

Originally Posted by peghall

Vented loop??? Why would that need replacing? It may need a new air valve, or may even have installed in the wrong place, but it doesn't make sense to replace a piece of curved PVC.

You're gonna end up paying 'em enough to buy 2 new GOOD toilets to try this and that and THEN end up buyng a new toilet anyway.

yes the large Vented loop, I have no idea its new! and it cost me $1300 to change the toilet through hull and raw water intake and two sinks and it worked before, but I nearly sunk the boat as it siphoned water over the toilet into the boat thats why I did it.

[Seahunter]

Originally Posted by peghall

WHAT "big vent?" Vented loop??? Why would that need replacing? It may need a new air valve, or may even have installed in the wrong place, but it doesn't make sense to replace a piece of curved PVC.

Ms Hall, there's no need to talk down to the poster; obviously he's new to the mechanical engineering of his heads, but is learning the fast and hard way. As for the "vented loop", Jabsco manual heads require a vent installed loop, please refer to Jabsco installation instructions for manual toilets. http://www.ittflowcontrol.com/files/artdoc5841.pdf

It's not uncommon either to have to replace waste lines after a number of years especially when flushing with raw water which leaves behind a build up calcified salt and marine growth that not only layers up on the inside of the lines (creating restrictions), but causes deterioration (especially to the vinyl type hose) allowing bleed through (symptomatic of a smelly bilge). This is why it's important that any moving parts should be exercised, lubricated frequently and systems flushed occasionally with fresh water.

[peghall]

You missed the point entirely...I'm not talking down to the poster, I'm taking aim squarely at a marina yard who obviously doesn't have a clue how the toilet works and is charging 'em a fortune ($1300 to install a manual toilet???? I'd buy a plane ticket and fix it myself for half that much INCLUDING the plane fare!) to prove it! It shouldn't be necessary to replace an INTAKE vented loop...and "large loop" obviously refers to the DISCHARGE vented loop! I tried when they first started this thread two months ago to offer some constructive help...there's not much more I can offer than to warn 'em off continuing to pay their marina through the nose NOT to fix it!

But if YOU have more constructive advice to offer 'em at this point, how 'bout offering it instead of criticizing me?

[sneuman]

Originally Posted by donradcliffe

I had the OP's problem, but it only showed up on the tack which put the head on the high side of the boat. Just put in a new pump assembly (I always carry a spare) and problem solved. If you want to spend the time fussing, its probably the wet/dry lever system, but since a new assembly isn't much more than a rebuild kit, why bother.

My experience with the Jabsco heads is that the mean time to failure is about 2 years, same as the Raritan, but a lot cheaper.

That long for the Jabscos? My Raritan has been going fine now for 4 years. Outlier, I guess.

[peghall]

If you can get two years out of a Jabsco manual, you're doing well. I don't know which Raritan toilet you managed to kill in two years, but you'd have to really WORK at it to get a PH II to fail in less than about 20 years!

[svHyLyte]

Originally Posted by peghall

If you can get two years out of a Jabsco manual, you're doing well. I don't know which Raritan toilet you managed to kill in two years, but you'd have to really WORK at it to get a PH II to fail in less than about 20 years!

Peg,

I admire your persistence on this and other threads. I have found that once having offered a suggestion and/or perhaps answered one or two follow-up questions on a subject with which I am well acquainted, there is no pay-off in continuing to respond to nay-sayers. In this case, most all of us older sailors/water-men/-women know Marine heads are not very complicated devices and properly maintained there is no reason why they should not last a very long time. Some, however, will manage to kill even the most robust equipment by doing exactly what the more experienced or knowledgable suggest against. No point arguing the matter. As was once observed, one can argue with a mule but it accomplishes nothing and irritates the mule.

FWIW....