Yesterday I had a pump-out service attempt to pump the boat's tanks. The forward went fine. The aft didn't. I checked for a Y-valve and found that they are installed only on "international" models. I was successful in using the macerator on both tanks on a past occasion. How come the fwd can be suctioned and not the aft? I have looked everywhere for a Y-valve without success. We're going out today to macerate the tank, but I would like to know for future reference. Ohn Richard s/v Jack's Place
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You prob'ly have a blocked vent in the aft tank
When the vent is blocked, both the pumpout and the macerator will just pull a vacuum...you can't empty the tank with either one. And continuing to suction it, especially with a pumpout if the pump is a particularly powerful one, can crack your tank. Any time you can't pump out, stop immediately! And check the vent for a blockage before trying again.
When the vent is blocked, both the pumpout and the macerator will just pull a vacuum...you can't empty the tank with either one. And continuing to suction it, especially with a pumpout if the pump is a particularly powerful one, can crack your tank. Any time you can't pump out, stop immediately! And check the vent for a blockage before trying again.
Thanks Peggy, but
We just got back from going out about three and a half miles to use the macerator. It cleared out the 23 gallon holding tank in less than a minute. So, I don't know what to say. The forward tank was able to suctioned, but not the aft.
We just got back from going out about three and a half miles to use the macerator. It cleared out the 23 gallon holding tank in less than a minute. So, I don't know what to say. The forward tank was able to suctioned, but not the aft.
Less than a minute? I don' TEEENK so...
A macerator can't pump that much that fast...about 5 gal/minute is about right. Check your tank level. I suspect the macerator may have pumped till it started pulling a vacuum.
A macerator can't pump that much that fast...about 5 gal/minute is about right. Check your tank level. I suspect the macerator may have pumped till it started pulling a vacuum.
John
I have a 420, and when I go out 3+ miles to pump my tanks, they both pump out quickly, like your, within 1-2 minutes..... Haven't had the problem that you are describing. Could there be a blockage in your pumpout hose that prevents the suction hose from actually getting into the tank?
I have a 420, and when I go out 3+ miles to pump my tanks, they both pump out quickly, like your, within 1-2 minutes..... Haven't had the problem that you are describing. Could there be a blockage in your pumpout hose that prevents the suction hose from actually getting into the tank?
Vaccum problem.
Hi, When we activate the aft macerator pump on our H410 air goes into the tank throug the head. Blocked vent? No, it is completely free. I guess the vent is not enough for the pumping out capacity. It is also true that the forward tank works without any problem. Rafael Perez Marinaclara - Valencia
Hi, When we activate the aft macerator pump on our H410 air goes into the tank throug the head. Blocked vent? No, it is completely free. I guess the vent is not enough for the pumping out capacity. It is also true that the forward tank works without any problem. Rafael Perez Marinaclara - Valencia
That should not happen, Rafael
Your tank can't be getting any air through the vent, 'cuz it takes a LOT of suction, to pull air through the toilet. Suction will pull air from the source of least resistance....and a 5/8" hose creates far less resistance than the slit in the joker valve in the toilet discharge. So the vent HAS to be blocked for the suction to pull air through the toilet. Put some water in the bowl--not a lot, just a cupful--before using the macerator next time...if the macerator pulls the water out of the bowl, you can be 100% certain that the tank isn't getting ANY air from any other source. And btw...if you're getting enough air through the toilet to dump the tank, the joker valve has to be long overdue for replacement too.
Your tank can't be getting any air through the vent, 'cuz it takes a LOT of suction, to pull air through the toilet. Suction will pull air from the source of least resistance....and a 5/8" hose creates far less resistance than the slit in the joker valve in the toilet discharge. So the vent HAS to be blocked for the suction to pull air through the toilet. Put some water in the bowl--not a lot, just a cupful--before using the macerator next time...if the macerator pulls the water out of the bowl, you can be 100% certain that the tank isn't getting ANY air from any other source. And btw...if you're getting enough air through the toilet to dump the tank, the joker valve has to be long overdue for replacement too.
joker valve?
Rafael, it sounds as if your head's joker valve might be shot (or jammed open by something that shouldn't have gone down the head in the first place.) It's at the top of the outflow line just downstream of the pump, a fairly easy replacement.
Rafael, it sounds as if your head's joker valve might be shot (or jammed open by something that shouldn't have gone down the head in the first place.) It's at the top of the outflow line just downstream of the pump, a fairly easy replacement.
Peggie
I agree with your clogged vent analysis, but the joker valve is designed to be a one way check valve allowing water etc. to leave the toilet bowl. Consequently, if that what's happening, and not the reverse, it's operation should be perfectly normal be it through suction or pressure. A.B.
I agree with your clogged vent analysis, but the joker valve is designed to be a one way check valve allowing water etc. to leave the toilet bowl. Consequently, if that what's happening, and not the reverse, it's operation should be perfectly normal be it through suction or pressure. A.B.
Not really, Al...
As I pointed out earlier, a completely open 5/8" vent hose will let a LOT more air into the tank than the slit in a joker valve. In fact, the suction pulling against it SHOULD cause the "lips" to close tighter (think "pucker factor"), not force them open. It takes a LOT of suction, without any other source of air, to pull air out of the toilet...less if the joker valve is "sprung" open, but still...if the vent is clear, it shouldn't happen at all.
As I pointed out earlier, a completely open 5/8" vent hose will let a LOT more air into the tank than the slit in a joker valve. In fact, the suction pulling against it SHOULD cause the "lips" to close tighter (think "pucker factor"), not force them open. It takes a LOT of suction, without any other source of air, to pull air out of the toilet...less if the joker valve is "sprung" open, but still...if the vent is clear, it shouldn't happen at all.
Peggie
Hi, I have not got the chance to check the vent hose properly, like passing a wire from end to end. But I've put my fingers at the vent's outlet while someone pumped the head (no comments) and I could feel the air going out. But for the moment I cant't tell wether the air flow is completely free or restricted. ALL of the Jabsco head pump is new (March 2001) body and rubbers (because someone at the shipyard used a screw driver damaging the valve seat). So, I think there should be some restriction at the vent hose. BTW. In order to get rid of the smell comming from the macerator tank, the marina boy who cleans the boat is going to put some liquid he uses for his chemical pottie in his caravan. I think he said AquaChem. Is it going to cause any damage to the tank, hoses and pump? I know the way to fight the smell is by aireation and helping the aerobic bacteria to proliferate. But it would take a long time to modify the macerator system. And time is scarce when your boat sits at 370 Km from home. Reagrds to ALL, Rafael Marinaclara - Valencia
Hi, I have not got the chance to check the vent hose properly, like passing a wire from end to end. But I've put my fingers at the vent's outlet while someone pumped the head (no comments) and I could feel the air going out. But for the moment I cant't tell wether the air flow is completely free or restricted. ALL of the Jabsco head pump is new (March 2001) body and rubbers (because someone at the shipyard used a screw driver damaging the valve seat). So, I think there should be some restriction at the vent hose. BTW. In order to get rid of the smell comming from the macerator tank, the marina boy who cleans the boat is going to put some liquid he uses for his chemical pottie in his caravan. I think he said AquaChem. Is it going to cause any damage to the tank, hoses and pump? I know the way to fight the smell is by aireation and helping the aerobic bacteria to proliferate. But it would take a long time to modify the macerator system. And time is scarce when your boat sits at 370 Km from home. Reagrds to ALL, Rafael Marinaclara - Valencia
fresh water flushing of head
Raphael, Though it's been mentioned here before on HOW by the Head Mistress, thought I'd reiterate that most of the foul smell from marine heads comes from anaerobic growth in the salt water rather than from the human wastes. To this end, flushing some fresh water through the toilet before leaving your boat for any length of time should cut down on bad odors. This is simple to do and sure makes a difference when coming back to a hot, closed up boat. Chris Webb s/v Grand Cru II
Raphael, Though it's been mentioned here before on HOW by the Head Mistress, thought I'd reiterate that most of the foul smell from marine heads comes from anaerobic growth in the salt water rather than from the human wastes. To this end, flushing some fresh water through the toilet before leaving your boat for any length of time should cut down on bad odors. This is simple to do and sure makes a difference when coming back to a hot, closed up boat. Chris Webb s/v Grand Cru II
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