One of our projects before spring launching is to install a macerator pump and new hoses. Our boat has one manual head, and here is the current set-up (sorry I don't have a diagram or photo): The output from the head goes to a siphon-breaker (upsidedown "U") and then to a Y-valve which lets you select either direct connection to a thru-hull (with seacock) or the holding tank. The holding tank discharge has a hose leading directly to a deck-mounted pump-out fitting. We want to re-plumb to the following configuration: The output from the head will go directly to the holding tank. The holding tank discharge hose will connect to a Y-valve where we can select either the deck-mounted pump-out fitting or the new macerator pump which will then connect to the seacock/thru-hull for use when we are offshore. So, I have two questions: Does it make sense to make these changes for functionality and reliability? Will we still need a siphon-breaker and if so where should it be installed? Thanks, Nancy
Re-Configuring and Re-Plumbing
- Thread starter NancyD
- Start date
- Status
Yes and Yes...
If you are going to be sailing where overboard discharge is permitted, and your sailing patterns require holding tank emptying away from the marina, a macerator is probably worthwhile. If I read your proposed routing of hoses correctly, that's the way they should be run. You DO need a vented loop in the toilet to holding tank/thru-hull unless your boat is so big that the toilet discharge will never be lower than the holding tank input and/or thru-hull at ANY angle of heel, pitch or yaw. Don't forget you also need one between the toilet pump and the bowl, on the INPUT side as well. Since you're replacing your hoses, have you considered using PVC pipe? Flexible hoses will always get permeated and become odiferous, but PVC won't. I have no idea if you could use PVC on your boat (because of routing and/or space considerations), but the link below is to a nifty installation on my boat model - I'm going to do this just as soon as my hoses start stinking.
Cheers, Bob s/v X SAIL R 8
If you are going to be sailing where overboard discharge is permitted, and your sailing patterns require holding tank emptying away from the marina, a macerator is probably worthwhile. If I read your proposed routing of hoses correctly, that's the way they should be run. You DO need a vented loop in the toilet to holding tank/thru-hull unless your boat is so big that the toilet discharge will never be lower than the holding tank input and/or thru-hull at ANY angle of heel, pitch or yaw. Don't forget you also need one between the toilet pump and the bowl, on the INPUT side as well. Since you're replacing your hoses, have you considered using PVC pipe? Flexible hoses will always get permeated and become odiferous, but PVC won't. I have no idea if you could use PVC on your boat (because of routing and/or space considerations), but the link below is to a nifty installation on my boat model - I'm going to do this just as soon as my hoses start stinking.
Cheers, Bob s/v X SAIL R 8
You really don't need the Y valve at all
on the discharge from the holding tank. Since the macerator has a seacock, just put a T where you were thinking of putting the Y valve. The cap on the pump out is closed if you're using the macerator. The seacock is closed if you're using the pump out. Simpler, one less valve to get stuck with "crap." .
on the discharge from the holding tank. Since the macerator has a seacock, just put a T where you were thinking of putting the Y valve. The cap on the pump out is closed if you're using the macerator. The seacock is closed if you're using the pump out. Simpler, one less valve to get stuck with "crap." .
"T"
My boat is set up the way Stu recommends with a "T" instead of a Y valve. I have found that when pumping the tank at the Marina some of the waste stays in the short section of tube between the bottom of the T and the seacock. I have bought a y valve and will install it when it warms up a bit.
My boat is set up the way Stu recommends with a "T" instead of a Y valve. I have found that when pumping the tank at the Marina some of the waste stays in the short section of tube between the bottom of the T and the seacock. I have bought a y valve and will install it when it warms up a bit.
Since you can legally dump the tank very rarely...
That is, only when you're in open ocean at least 3 miles from the south side of LI, it makes sense to remove the y-valves that allows you to choose between flushing directly overboard or going into the tank...'cuz you have to go into the tank every where in LIS. You will need two vented loops--one in the head intake (between the pump and the bowl) and a second one between the overboard discharge pump and the thru-hull. You do NOT need one between the head the tank. I strongly advise using a y-valve instead of just a tee fitting in the tank discharge line...and put it as close to the tank as possible. A y-valve allows you to cut off the flow of waste from the tank to the pump to service the pump. Since the only time anyone ever discovers that the pump isn't working is when a tank is full, being able to do that can come in very handy. Since you can only dump the tank when you're offshore in open ocean, the pump is likely to sit a long time between uses. Lack of use will cause a macerator impeller to get stuck tight to its housing, requiring frequent replacement. So IMO, yuu'd be better off installing eithr a manual diaphragm pump or an electrica diaphragm pump instead.
That is, only when you're in open ocean at least 3 miles from the south side of LI, it makes sense to remove the y-valves that allows you to choose between flushing directly overboard or going into the tank...'cuz you have to go into the tank every where in LIS. You will need two vented loops--one in the head intake (between the pump and the bowl) and a second one between the overboard discharge pump and the thru-hull. You do NOT need one between the head the tank. I strongly advise using a y-valve instead of just a tee fitting in the tank discharge line...and put it as close to the tank as possible. A y-valve allows you to cut off the flow of waste from the tank to the pump to service the pump. Since the only time anyone ever discovers that the pump isn't working is when a tank is full, being able to do that can come in very handy. Since you can only dump the tank when you're offshore in open ocean, the pump is likely to sit a long time between uses. Lack of use will cause a macerator impeller to get stuck tight to its housing, requiring frequent replacement. So IMO, yuu'd be better off installing eithr a manual diaphragm pump or an electrica diaphragm pump instead.
Woops, I was wrong
w/o the Y valve servicing doesn't work. Sorry, wrong recommendations, Pegie's right.
w/o the Y valve servicing doesn't work. Sorry, wrong recommendations, Pegie's right.
Thanks All - I understand everything except
The vented loop on the intake - it seems like the pump and the bowl are one integral unit. I don't think there is any loop there now. Can someone give me more details as to exactly where this would be installed?
The vented loop on the intake - it seems like the pump and the bowl are one integral unit. I don't think there is any loop there now. Can someone give me more details as to exactly where this would be installed?
Vent loop
Check the Jabsco web site below. Fugure 1 shows you how. http://www.jabsco.com//prodInfo/overview/43001_0507_01_03.pdf
Check the Jabsco web site below. Fugure 1 shows you how. http://www.jabsco.com//prodInfo/overview/43001_0507_01_03.pdf
Hi Peggie, why do you need a vented loop...
between the overboard discharge pump and the through hull? We do not have one on our boat and we've never had a problem. Of course the through hull is only open during discharge. Our boat has vented loops between the raw water intakes and the heads, but that's it. Our overboard hose comes directly from the tank to the macerator pump to the through hull, all of which are below the waterline. Terry
between the overboard discharge pump and the through hull? We do not have one on our boat and we've never had a problem. Of course the through hull is only open during discharge. Our boat has vented loops between the raw water intakes and the heads, but that's it. Our overboard hose comes directly from the tank to the macerator pump to the through hull, all of which are below the waterline. Terry
One reason...
ABYC standards call for vented loops on all below waterline connections (Yes, I know boat builders don't always do everything the standards call for, but that's another issue). A GOOD surveyor doing an insurance or pre-purchase would almost certainly require it, 'cuz it's a safety issue. Another reason: you're careful to make sure the seacock is open only while the tank is being dumped...but seacocks CAN leak, and people are fallible. If the next owner of your boat isn't any more knowledge than most of today's typical first time owner, he won't know he needs one, and will also decide it's easier to leave the thru-hull open. All of which are the reasons why ABYC standards call for a vented loop there. Btw...if your head intake vented loops are between the thru-hull and the pump, they're in the wrong place unless your toilet is a Groco Model K or a W-C Skipper. When the vented loop is between the thru-hull and pump, the pump pulls in air through then vent in the loop...that interferes with the pump's ability to prime. And, fwiw, the Strait is the only place in your waters where it's legal to dump a tank...'cuz that's the only place anywhere in the San Juans where it's possible to be more than 3 miles from an island in any direction.
ABYC standards call for vented loops on all below waterline connections (Yes, I know boat builders don't always do everything the standards call for, but that's another issue). A GOOD surveyor doing an insurance or pre-purchase would almost certainly require it, 'cuz it's a safety issue. Another reason: you're careful to make sure the seacock is open only while the tank is being dumped...but seacocks CAN leak, and people are fallible. If the next owner of your boat isn't any more knowledge than most of today's typical first time owner, he won't know he needs one, and will also decide it's easier to leave the thru-hull open. All of which are the reasons why ABYC standards call for a vented loop there. Btw...if your head intake vented loops are between the thru-hull and the pump, they're in the wrong place unless your toilet is a Groco Model K or a W-C Skipper. When the vented loop is between the thru-hull and pump, the pump pulls in air through then vent in the loop...that interferes with the pump's ability to prime. And, fwiw, the Strait is the only place in your waters where it's legal to dump a tank...'cuz that's the only place anywhere in the San Juans where it's possible to be more than 3 miles from an island in any direction.
Hi Peggie, I guess I should look into the ABYC...
standards, because the only though hulls that have the vented loop on our boat are the heads. I thought the purpose of the vented loop was to prevent siphoning after the raw water pump completed is work. Our vented loop has a solenoid operated valve that closes the vent to allow the pump to draw raw water, then opens when the motor shuts off, which stops any siphoning. In the three surveyors that have had involvement with our boats vented loops have never been an issue other than with the heads. So, by the standard you refer to, raw water that is pumped for the propulsion engine, Genset, heat pumps, macerator, plus sink drains, should all have vented loops? Something seems fishy here, with all due respect. I fail to see how a vented loop is going to help prevent raw water from siphoning back into the holding tank when the waste water is being ejected from the boat. It defies the law of physics to my simple mind. I guess I need to take Hunter to task because the vented loops for the head are between the through hull and the pump and I could be wrong but I'm pretty sure our heads are not of the two models you mention. Terry P.S. I do not dump in US waters because most all marinas have pump out stations. Different story in Canadian waters (Gulf Islands, Discovery Islands, etc.) where we do most of our cruising. Few marinas there have pump out stations and are non-existent the further north you go. Also, FWIW, there are places in the San Juan Islands (other than the Strait of Juan de Fuca) where you can be at least three miles from an island in any direction.
standards, because the only though hulls that have the vented loop on our boat are the heads. I thought the purpose of the vented loop was to prevent siphoning after the raw water pump completed is work. Our vented loop has a solenoid operated valve that closes the vent to allow the pump to draw raw water, then opens when the motor shuts off, which stops any siphoning. In the three surveyors that have had involvement with our boats vented loops have never been an issue other than with the heads. So, by the standard you refer to, raw water that is pumped for the propulsion engine, Genset, heat pumps, macerator, plus sink drains, should all have vented loops? Something seems fishy here, with all due respect. I fail to see how a vented loop is going to help prevent raw water from siphoning back into the holding tank when the waste water is being ejected from the boat. It defies the law of physics to my simple mind. I guess I need to take Hunter to task because the vented loops for the head are between the through hull and the pump and I could be wrong but I'm pretty sure our heads are not of the two models you mention. Terry P.S. I do not dump in US waters because most all marinas have pump out stations. Different story in Canadian waters (Gulf Islands, Discovery Islands, etc.) where we do most of our cruising. Few marinas there have pump out stations and are non-existent the further north you go. Also, FWIW, there are places in the San Juan Islands (other than the Strait of Juan de Fuca) where you can be at least three miles from an island in any direction.
Hey Terry
Because the overboard discharge is used infrequently, I removed my vented loop between the manual discharge pump and the thru hull. The loop was taking up space in a hanging locker and was just more hose to stink. Upen the thru hull value, pump overboard, close the thru hull valve. Pump and shut off valve are next to each other, so I won't forget to close the valve. Peggy told me it wouldn't pass survey. I am satisfied with this set up. Sink drains don't need loops because bottom of sink above water line, so can't fill up and overflow.
Because the overboard discharge is used infrequently, I removed my vented loop between the manual discharge pump and the thru hull. The loop was taking up space in a hanging locker and was just more hose to stink. Upen the thru hull value, pump overboard, close the thru hull valve. Pump and shut off valve are next to each other, so I won't forget to close the valve. Peggy told me it wouldn't pass survey. I am satisfied with this set up. Sink drains don't need loops because bottom of sink above water line, so can't fill up and overflow.
Small Vented Loop
If we install a small vented loop between the pump and bowl like in Peggy's photo, can the hoses go down (below the waterline) before they go up? We would have to mount the loop on the other side of a bulkhead, behind the head.
If we install a small vented loop between the pump and bowl like in Peggy's photo, can the hoses go down (below the waterline) before they go up? We would have to mount the loop on the other side of a bulkhead, behind the head.
Down is fine....
as long as the TOP of the vented loop is 6 or more inches above the waterline at any angle of heel. FWIW, my surveyor wrote the following as an 'advisory recommendation' when I bought my boat: "Provide vented loop protection to toilet intake and discharge." The discharge vented loop is there to keep the holding tank from emptying itself into your toilet - is that important to you? Terry, I've never heard of the setup you have, but as long as the solenoid works, it sounds like your toilet will as well. Vented loop on the engine raw-water intake? I don't think so - doesn't that water just flow through the engine and out the exhaust? I'm thinking there's no opening for that water to get into the boat. Also, the exhaust DOES have a vented loop on it, because siphoned water CAN get into the engine (uh-oh). Are the toilet vented loops essential or even critical? Most of the time, obviously not, considering the number of boats in the water that don't have them, but still manage not to sink or siphon the contents of a full holding tank back through the toilet into the bilge. But using the same logic, I've never needed my life jackets, harnesses, jack lines, manual bilge pump, backup GPS, spare anchors and rodes, flares, etc., etc., etc.... or even those tapered wooden plugs! I wouldn't leave ANY of those items behind.... would you? Cheers, Bob s/v X SAIL R8
as long as the TOP of the vented loop is 6 or more inches above the waterline at any angle of heel. FWIW, my surveyor wrote the following as an 'advisory recommendation' when I bought my boat: "Provide vented loop protection to toilet intake and discharge." The discharge vented loop is there to keep the holding tank from emptying itself into your toilet - is that important to you? Terry, I've never heard of the setup you have, but as long as the solenoid works, it sounds like your toilet will as well. Vented loop on the engine raw-water intake? I don't think so - doesn't that water just flow through the engine and out the exhaust? I'm thinking there's no opening for that water to get into the boat. Also, the exhaust DOES have a vented loop on it, because siphoned water CAN get into the engine (uh-oh). Are the toilet vented loops essential or even critical? Most of the time, obviously not, considering the number of boats in the water that don't have them, but still manage not to sink or siphon the contents of a full holding tank back through the toilet into the bilge. But using the same logic, I've never needed my life jackets, harnesses, jack lines, manual bilge pump, backup GPS, spare anchors and rodes, flares, etc., etc., etc.... or even those tapered wooden plugs! I wouldn't leave ANY of those items behind.... would you? Cheers, Bob s/v X SAIL R8
Hi Bob, on our boat I'm pretty sure that the....
purpose of the vented loop is to prevent siphoning of raw water into the toilet bowl after you finish discharging the contents into the holding tank. One our boat the raw water/macerator combo electric pump is attached to the toilet. Since the toilet, pump, tank, etc. are all below the waterline, without the vented loop and solenoid anti-siphon valve, the raw water would continue to siphon into the bowl. Of course I always make sure to keep all through hulls closed when not in use to prevent such a thing from happening. Then again I have been known to leave the tank discharge pump through hull open and over time raw water trickled passed the pump impeller and filled the tank. It happened while I was cruising so no problem. Maybe it could have been worse. Terry
purpose of the vented loop is to prevent siphoning of raw water into the toilet bowl after you finish discharging the contents into the holding tank. One our boat the raw water/macerator combo electric pump is attached to the toilet. Since the toilet, pump, tank, etc. are all below the waterline, without the vented loop and solenoid anti-siphon valve, the raw water would continue to siphon into the bowl. Of course I always make sure to keep all through hulls closed when not in use to prevent such a thing from happening. Then again I have been known to leave the tank discharge pump through hull open and over time raw water trickled passed the pump impeller and filled the tank. It happened while I was cruising so no problem. Maybe it could have been worse. Terry
Toilet vented loops are essential if the toilet is
below the waterline. Not between the head and tank, but in the intake and in any line that goes from the toilet or the tank to a below-waterline thru-hull. Why? Because water seeks its own level...so any time a thru-hull is open, water will rise in that line to the waterline. It doesn't need a siphon to do that. If the toilet bowl is at or below the waterline, and a discharge thru-hull is open, water WILL rise in the head discharge line to the waterline. If the waterline is higher than the top of the bowl, water will keep rising till someone notices the flood running out from the under the head door and closes the seacock...or, if no one is aboard, the boat sinks. If the intake thru-hull is open and the wet/dry valve is left in the wet mode--or fails (which happens more often than you think), water will rise to the waterline...and if the waterline is higher than the bowl, till someone notices the flood running out from the under the head door and closes the seacock...or, if no one is aboard, the boat sinks. If the tank or any part of it is below the waterline, and the thru-hull is left open, water will rise in the tank to the waterline. Less likely to sink your boat unless the whole tank is below the waterline, but it can make a hell of a mess in the head. A vented loop has two functions: 1) a siphon break. Flushing a toilet--or operating any pump--starts a siphon...the vented is an air break that breaks it. 2) an arch in the line above the waterline...water will only rise TO the waterline, it won't rise any higher. So your boat is protected if you forget to close the seacocks when you leave the boat. Leaving them open and relying on the wet/dry valve and/or making sure it's closed is the best way to sink your boat. It's also important to understand that waterline on a boat isn't static...wave action can change it minute to minute...fuel (6.5/lbs/gal) and water (8.33 lbs/gal)can raise or lower it, as can people and everything they bring aboard. So if you think you're safe if the top of your bowl is an inch or two above the waterline, you're not...a storm with sustained winds that cause your boat to heel just a few degrees can put it below the waterline. That's why vented loops are supposed to be at least 6-8" above waterline any angle of heel. Nancy, why would have to mount the loop on the other side of a bulkhead? Why not directly above the toilet (please don't say it's for cosmetic reasons!)? Even if there is a good reason, why would you have to run the line down to get to the other side of it? Why can't you just cut an opening in the bottom of the bulkhead for the hose to pass through?
below the waterline. Not between the head and tank, but in the intake and in any line that goes from the toilet or the tank to a below-waterline thru-hull. Why? Because water seeks its own level...so any time a thru-hull is open, water will rise in that line to the waterline. It doesn't need a siphon to do that. If the toilet bowl is at or below the waterline, and a discharge thru-hull is open, water WILL rise in the head discharge line to the waterline. If the waterline is higher than the top of the bowl, water will keep rising till someone notices the flood running out from the under the head door and closes the seacock...or, if no one is aboard, the boat sinks. If the intake thru-hull is open and the wet/dry valve is left in the wet mode--or fails (which happens more often than you think), water will rise to the waterline...and if the waterline is higher than the bowl, till someone notices the flood running out from the under the head door and closes the seacock...or, if no one is aboard, the boat sinks. If the tank or any part of it is below the waterline, and the thru-hull is left open, water will rise in the tank to the waterline. Less likely to sink your boat unless the whole tank is below the waterline, but it can make a hell of a mess in the head. A vented loop has two functions: 1) a siphon break. Flushing a toilet--or operating any pump--starts a siphon...the vented is an air break that breaks it. 2) an arch in the line above the waterline...water will only rise TO the waterline, it won't rise any higher. So your boat is protected if you forget to close the seacocks when you leave the boat. Leaving them open and relying on the wet/dry valve and/or making sure it's closed is the best way to sink your boat. It's also important to understand that waterline on a boat isn't static...wave action can change it minute to minute...fuel (6.5/lbs/gal) and water (8.33 lbs/gal)can raise or lower it, as can people and everything they bring aboard. So if you think you're safe if the top of your bowl is an inch or two above the waterline, you're not...a storm with sustained winds that cause your boat to heel just a few degrees can put it below the waterline. That's why vented loops are supposed to be at least 6-8" above waterline any angle of heel. Nancy, why would have to mount the loop on the other side of a bulkhead? Why not directly above the toilet (please don't say it's for cosmetic reasons!)? Even if there is a good reason, why would you have to run the line down to get to the other side of it? Why can't you just cut an opening in the bottom of the bulkhead for the hose to pass through?
Peggy,
Yes, it is for cosmetic reasons. With each of our repairs and upgrades, my husband and I have tried very hard to route wiring and hoses so they are out of sight. The result has been a "neat" look that we don't want to lose. The hoses would go through the bottom of the bulkhead right behind the head, and then up the other side to where the loop would be mounted, above the waterline. One more question - can you mount a vented loop on the intake side of a pump or only on the output side. In other words, can you "pull" water through it instead of "pushing" the water through the loop. Thanks for all of your help! Nancy
Yes, it is for cosmetic reasons. With each of our repairs and upgrades, my husband and I have tried very hard to route wiring and hoses so they are out of sight. The result has been a "neat" look that we don't want to lose. The hoses would go through the bottom of the bulkhead right behind the head, and then up the other side to where the loop would be mounted, above the waterline. One more question - can you mount a vented loop on the intake side of a pump or only on the output side. In other words, can you "pull" water through it instead of "pushing" the water through the loop. Thanks for all of your help! Nancy
- Status