Electric head operation

Dave_E · 10-02-2017, 12:28 PM

Hi All,

The good ship has 2 heads, the fwd head has a 15' run to the holding tank and the aft head has a 10' run. I plumed 1.5" hose throughout. Haven't got things hooked up yet and never had electric heads before. So here is a seemingly dopey question.

If I flush the fwd head with a 15' run to the tank... I'd have to keep the button pushed for more than a few seconds to get the contents back to the tank. I'm going to assume that you push the button... clear the bowl for a few seconds, the hose somewhere back along that 15' is always going to have goo in it (especially low spots), correct? Hens the need for really good hose?

Those of you with bigger boats, how long do you flush your electric heads? Those of you with manuals... how many pumps?

Thanks - Dave

DHeckrotte · 10-02-2017, 12:57 PM

For starters, read the instructions on installation of the heads. Continue by calling the mfr if the instructions leave you in doubt.

Smaller dia hose would reduce the amount of sewage left to settle in it. So would sloping the hose from head to tank. And eliminate sags in the run.

**Shrew** · 10-02-2017, 01:25 PM

We flush until the bowl is clear. We'll flush the entire line prior to a pump-out or if we're going to leave the boat for a few days. (If we're going to leave the boat for a few days we typically get a pump-out anyway).

Flatswing · 10-03-2017, 06:58 AM

I believe Peggy Hall's advice on this was to flush longer, to leave clean water in the lines. Pump out more often as a result.

Pgitug · 10-03-2017, 08:32 AM

Am I wrong or is this the perfect scenario for a vacuflush system? If you use electric toilets and flush the line each time you are putting more than a gallon of water in the holding at every flush. With a Vacuflush system that does not happen. Correct?

catalinajack · 10-03-2017, 08:44 AM

And the long lines stay filled with crap. Whether vac or elec, a sufficient amount of water needs to be put through the lines to push everything through.

Rufus · 10-03-2017, 10:23 AM

When I re-plumbed the black water system on our boat I had two objectives in mind. Minimal water usage and a water trap (clean water in the bowl) to preclude odors in the boat. There's only one realistic solution and that is a riser immediately after the head discharge line. So the basic design is....head discharge...to riser (about 2.5 feet)....to vented loop...to downhill run to the tank. That meant completely rerouting everything. The risers/loops fit in the cabinets beside the heads so they're out of sight. The (mostly hard PVC pipe) lines to the tank required new elevated holes through bulkheads. Big effort, but worth the trouble over the long haul. Reduced water usage and no stink.

HeadMistress · 10-03-2017, 10:26 AM

The boat should have two holding tanks, each within about 6' of a toilet...'cuz except for the Tecma, Raritan Elegance, Raritan Atlantes and maybe a couple of others, 6' is as far a bowl contents will move in the amount of time anyone will leave his finger on the flush button or pump a manual toilet without a lot of help from gravity.

There is a way to give most toilets that assist from gravity: Any toilet, manual or electric, that's working anywhere near factory specs can lift bowl contents up to 4'. So unless you want to either move one tank and add a second one or replace the toilets with ones that have pumps powerful enough to push waste to the tank, the only solution is to run the toilet discharge line straight up from the toilet and over a loop that's high enough give you at least a few degrees of downhill slope to the inlet fitting on the tank. That will allow you to flush only long enough to push the bowl contents over the top of the loop....gravity will get it the rest of the way. Follow that with another quart or so of water to rinse the hose behind the flush. Once a day, flush a full bowlful of clean water.

And btw...sanitation hose is the last place you want to try to save money if you only want to have to do this job once. What did you buy?

Am I wrong or is this the perfect scenario for a vacuflush system? If you use electric toilets and flush the line each time you are putting more than a gallon of water in the holding at every flush. With a Vacuflush system that does not happen. Correct?

Nope. The VacuFlush suction only pulls bowl contents as far as the pump...the pump then has to push it the rest of the way to its destination--tank, thru-hull or treatment device. The pump will only run as long as it takes to re-establish the prescribed amount of vacuum between the bowl and the pump...so if the run from the pump is too long for it push waste that far before it shuts off, that's as far as the flush will move till the next flush. It takes considerably more water than SeaLand (now Dometic) claims it needs to keep the plumbing rinsed out. Using too little water is leading cause for at least 90% of problems with it.

I've written a piece I call "VacuFlush 101" that explains how it works (an amazing number of owners think they do, but don't) and how to prevent problems with it that I'll be glad to send to anyone who wants to send me a PM that includes your email address...no way to attach anything to a PM.

Peggie
"If you can't explain it to a six year old, you don't completely understand it yourself." --Albert Einstein

HeadMistress · 10-03-2017, 10:33 AM

When I re-plumbed the black water system on our boat I had two objectives in mind. Minimal water usage and a water trap (clean water in the bowl) to preclude odors in the boat.

Traps are needed in household toilets because there are no valves in household toilet. The joker valve in marine toilets eliminates the need for a trap. You'll never have any odor from the tank or discharge line if you replace it annually. That also provides you with the opportunity to check the inside of the discharge hose for any sea water or hard water buildup in it.

Rufus · 10-03-2017, 10:55 AM

Quote:

Originally Posted by HeadMistress

When I re-plumbed the black water system on our boat I had two objectives in mind. Minimal water usage and a water trap (clean water in the bowl) to preclude odors in the boat.

Traps are needed in household toilets because there are no valves in household toilet. The joker valve in marine toilets eliminates the need for a trap. You'll never have any odor from the tank or discharge line if you replace it annually. That also provides you with the opportunity to check the inside of the discharge hose for any sea water or hard water buildup in it.

Sorry, joker valves leak and stink. They're also an unnecessary maintenance item. Further, if a loop/riser is used as I (and I believe you) proposed, there will be water left in the bowl by default as it will drain back from the riser/stand pipe. By the way, I added a second (aft) holding tank during my redesign. However, it wasn't absolutely mandatory to achieve my objectives. Once the water is over the loop/riser, gravity does the rest.

DHeckrotte · 10-03-2017, 11:14 AM

I'd add my guess/expectation that, while a joker in good condition and squeaky-clean might tend to be airtight, one that's been in service won't be. Further, a joker that is installed so that the fluids that have passed are allowed to fall back on it, as is the case with a riser/loop in the system, will tend to close/seal because of the weight of the fluids. A joker that's impaired by age, salt, deleterious substances, etc. won't be airtight nor fluid tight, but will do most of its job - most of the time; a continued passing of clean water will make its performance more adequate.

FoxtrotCharlie · 10-03-2017, 11:22 AM

I do believe the Head Mistress said joker valves won't leak 'if replaced annually'

Dave_E · 10-03-2017, 11:35 AM

Good input Everyone, THANKS! Unfortunately, our boat isn't big enough to have 2 holding tanks. I do have a trap on the fwd head and no smell (even using salt water). The back head had no trap and it smelled! Thanks for the joker valve input, I will replace both immediately. Agreed with not skimping on the quality of the hose!

Thanks - Dave

Rufus · 10-03-2017, 11:52 AM

Quote:

Originally Posted by FoxtrotCharlie

I do believe the Head Mistress said joker valves won't leak 'if replaced annually'

I do believe the Head Mistress is incorrect. Without a standpipe/elevated loop solids come back and stick in the valve unless gallons of clean water are pushed through. That's not the real world. (The original post was about high water use per flush).

The standpipe/loop design is what boat manufacturers should have been installing in the first place. They didn't because it was less trouble and expense to string flexible hose willy nilly. Also, I've never seen any old recommendations from the head manufacturer's to use this preferred method from the gitgo. The Head Mistress didn't get the flick until I started advocating this ten years ago.

HeadMistress · 10-03-2017, 12:55 PM

I do believe the Head Mistress is incorrect. Without a standpipe/elevated loop solids come back and stick in the valve unless gallons of clean water are pushed through.

Water--and waste--do run downhill, whether in an uphill run from the toilet to the tank or from the top of the loop, if the toilet isn't flushed long enough to push the flush over the tank.

Apparently you were never on any of the sailboat sites where I've been recommending a loop in the discharge line since 1997 because it's almost impossible to have a downhill run to the tank on most sailboats.

Rufus · 10-03-2017, 02:09 PM

Quote:

Originally Posted by HeadMistress

I do believe the Head Mistress is incorrect. Without a standpipe/elevated loop solids come back and stick in the valve unless gallons of clean water are pushed through.

Water--and waste--do run downhill, whether in an uphill run from the toilet to the tank or from the top of the loop, if the toilet isn't flushed long enough to push the flush over the tank.

Apparently you were never on any of the sailboat sites where I've been recommending a loop in the discharge line since 1997 because it's almost impossible to have a downhill run to the tank on most sailboats.

Yes, water does indeed run down hill.

What's the point of a raised loop in a sail boat where it's almost impossible to get a down hill run to the tank? You just said a joker seals reliably. I'd think sail boaters would object to water in the bowl given heel angles. (There will be water from the up hill side of the loop that drains back to the bowl).

HeadMistress · 10-03-2017, 03:09 PM

What's the point of a raised loop in a sail boat where it's almost impossible to get a down hill run to the tank?

It does two things: Provides the same assist from gravity while reducing the amount of flush water needed that I described in post #8, and prevents tank contents from running back to the toilet when the boat heels. Yes, a function joked will keep it out of the bowl, but the loop provides the downhill run to send it back to the tank when boat uprights or changes tacks instead of leaving it to sit in the line to permeate it.

Rufus · 10-03-2017, 04:38 PM

Quote:

Originally Posted by HeadMistress

What's the point of a raised loop in a sail boat where it's almost impossible to get a down hill run to the tank?

It does two things: Provides the same assist from gravity while reducing the amount of flush water needed that I described in post #8, and prevents tank contents from running back to the toilet when the boat heels. Yes, a function joked will keep it out of the bowl, but the loop provides the downhill run to send it back to the tank when boat uprights or changes tacks instead of leaving it to sit in the line to permeate it.

This only makes sense if in addition to the loop there is a constant slope downhill run from the loop to the tank no low spots. But in post #15 you said this is almost impossible to achieve on most sailboats. Which is it?

HeadMistress · 10-03-2017, 04:59 PM

It's almost impossible to have a direct downhill run from the toilet to the tank on most sailboats because the toilet on most sailboats is at or below the waterline and most sailboats have bilges that are too shallow for a tank. So creating the constant downhill run from a loop immediately after the toilet that's slightly higher than the tank is the whole point of installing the loop, rufus.

Rufus · 10-03-2017, 05:32 PM

Quote:

Originally Posted by HeadMistress

It's almost impossible to have a direct downhill run from the toilet to the tank on most sailboats because the toilet on most sailboats is at or below the waterline and most sailboats have bilges that are too shallow for a tank. So creating the constant downhill run from a loop immediately after the toilet that's slightly higher than the tank is the whole point of installing the loop, rufus.

I think a light just went on for you...and I believe your earlier remark that it's almost impossible to achieve a down hill run in a sailboat also applies to a raised loop. It was very difficult to achieve in a 45' power boat. By the way, your statement that the loop provides the downhill run to the tank is technically inaccurate. The downhill run is provided by the exit line from the loop. Obviously a loop can be installed by itself without a downhill run and provide the benefit of a guaranteed clean water stink barrier in the bowl. And if an owner is OK with sewage in a low spot in a hose line and pushing it toward the tank with each subsequent flush, this is an option. Far better than a joker.