I have a problem when the fresh water tank is half full and we have been sailing and heeling over. When we go to turn on the water pressure the pump just runs. I presume that water has drained out of the pump, back into the tank and once the boat comes upright we get air caught at the pump. The only way so far that we have cleared the air is to fill the tank up to the top. (which is difficult unless I am at the dock) Has anybody got a solution?
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Forrest B True
Fresh water pump
I'm assuming this only happens when you are on a starboard tack.A simple remedy is to install an outlet on the port side and tee into the existing plastic piping. I had to install another cleanout plate in the water tank to do this but it really is no big job.
I'm assuming this only happens when you are on a starboard tack.A simple remedy is to install an outlet on the port side and tee into the existing plastic piping. I had to install another cleanout plate in the water tank to do this but it really is no big job.
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Peggie Hall/HeadMistress
Pump SHOULD reprime quickly
It makes sense that you might not be able to run water while heeled over if the water level is low enough to put the tank outlet fitting above the surface. But once you're level again, the pump should have no trouble repriming...fresh water pumps don't GET "air locks." I suspect that what's really happening is: water is filling your tank's vent linewhen you're heeled...there's enough of a sag in the vent line to trap some water in it, causing the pump to pull a vacuum--which will prevent it from pumping any water. Refilling the tank creates enough pressure as incoming water displaces air in the tank to clear it. So check your water tank vent line...and if I'm right, the cure is simple: replace the sag with an arch.
It makes sense that you might not be able to run water while heeled over if the water level is low enough to put the tank outlet fitting above the surface. But once you're level again, the pump should have no trouble repriming...fresh water pumps don't GET "air locks." I suspect that what's really happening is: water is filling your tank's vent linewhen you're heeled...there's enough of a sag in the vent line to trap some water in it, causing the pump to pull a vacuum--which will prevent it from pumping any water. Refilling the tank creates enough pressure as incoming water displaces air in the tank to clear it. So check your water tank vent line...and if I'm right, the cure is simple: replace the sag with an arch.
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Ed Schenck
Hate to disagree so . . .
I won't. But will add that I definitely lose prime when I empty tanks for haulout. Only way to NOT pump air is to: 1) fill the tanks(never tried and don't want that much water) or 2) prime the inlet hose. To prime I remove the inlet hose from the manifold(two 50 gal. tanks to one inlet), hold as high as possible and fill with water from a cup. Holding my thumb over the hose I reinstall and clamp. Turn the valve to whichever tank and turn on pump. Takes about 15 seconds to build pressure and shut off. If it were a vent problem I don't think this would work. Been wrong before.
I won't. But will add that I definitely lose prime when I empty tanks for haulout. Only way to NOT pump air is to: 1) fill the tanks(never tried and don't want that much water) or 2) prime the inlet hose. To prime I remove the inlet hose from the manifold(two 50 gal. tanks to one inlet), hold as high as possible and fill with water from a cup. Holding my thumb over the hose I reinstall and clamp. Turn the valve to whichever tank and turn on pump. Takes about 15 seconds to build pressure and shut off. If it were a vent problem I don't think this would work. Been wrong before.
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Peggie Hall/HeadMistress
Of course you lose primes when you empty the tanks
Any time the level in the tank drops below the top of the discharge fitting, the pump is gonna start sucking air and lose prime. Fill the tank high enough to completely cover the discharge fitting, and the pump primes again. However, I wasn't aware that these boats have two linked tanks. Without seeing what's happening, all I can do is take a guess that when the boat is heeled, ALL the water is running back into one tank, causing the pump to suck air from the other one. That WOULD prevent it from priming until the two tanks have equalized again--or at least until both discharge fittings in both tanks are completely below the water level again. Or...if the water level is low enough and the empty tank is lower in the boat than the one that ends up with all the water in it due to heeling, they may never be able to equalize enough to allow the pump to prime again till more water is addded...or, if the diameter of the manifold is small, it may just take so long to equalize that you give up. Whatever IS happening, it's happening because something is causing the pump to either pull a vacuum or suck air after the boat has been on whichever tack for long enough to make it happen...'cuz water pumps don't get "air locks"--they only refuse to prime if water isn't getting to 'em or they're pulling against a vacuum. Figure out how to prevent whichever it is, and you solve the problem.
Any time the level in the tank drops below the top of the discharge fitting, the pump is gonna start sucking air and lose prime. Fill the tank high enough to completely cover the discharge fitting, and the pump primes again. However, I wasn't aware that these boats have two linked tanks. Without seeing what's happening, all I can do is take a guess that when the boat is heeled, ALL the water is running back into one tank, causing the pump to suck air from the other one. That WOULD prevent it from priming until the two tanks have equalized again--or at least until both discharge fittings in both tanks are completely below the water level again. Or...if the water level is low enough and the empty tank is lower in the boat than the one that ends up with all the water in it due to heeling, they may never be able to equalize enough to allow the pump to prime again till more water is addded...or, if the diameter of the manifold is small, it may just take so long to equalize that you give up. Whatever IS happening, it's happening because something is causing the pump to either pull a vacuum or suck air after the boat has been on whichever tack for long enough to make it happen...'cuz water pumps don't get "air locks"--they only refuse to prime if water isn't getting to 'em or they're pulling against a vacuum. Figure out how to prevent whichever it is, and you solve the problem.
Couple of things
First: Peggie, these boats did not come with two tanks. They have a single tank that is located under the aft quarter berth. The tank holds about 35 gal. Second: Andrew did not mention if he is using the original primary tank or does he maybe have a replacement tank or an additional tank. Andrew: We need some more info. Do you have multiple tanks? or is this the single original tank? I have a 1985 H'31 and have never had this problem from the original primary tank. That does not mean that there isn't some different about yours.
First: Peggie, these boats did not come with two tanks. They have a single tank that is located under the aft quarter berth. The tank holds about 35 gal. Second: Andrew did not mention if he is using the original primary tank or does he maybe have a replacement tank or an additional tank. Andrew: We need some more info. Do you have multiple tanks? or is this the single original tank? I have a 1985 H'31 and have never had this problem from the original primary tank. That does not mean that there isn't some different about yours.
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Andrew Benjamin
Peg
Hunter 31 has one freshwater tank on the port side which "holds 31 gals". However I have measured this and have counted 22 Gallons. I need every drop I have got. I have made two inspection holes in the top of the tank to find out what the problem was and can find nothing wrong. Since the existing outlet is on the starboard side of the tank and the port side of the tank is the hull (I think) I do not have an oppotunity to make an additional exit. Thanks to you all in showing your interest. Andrew
Hunter 31 has one freshwater tank on the port side which "holds 31 gals". However I have measured this and have counted 22 Gallons. I need every drop I have got. I have made two inspection holes in the top of the tank to find out what the problem was and can find nothing wrong. Since the existing outlet is on the starboard side of the tank and the port side of the tank is the hull (I think) I do not have an oppotunity to make an additional exit. Thanks to you all in showing your interest. Andrew
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Peggie Hall/HeadMistress
Thinking....
How old is your (and anyone else who's having the same problem)? How many feet from the tank? And is it above, at the same level, or below the tank discharge fitting? I'm looking for a pattern here...
How old is your (and anyone else who's having the same problem)? How many feet from the tank? And is it above, at the same level, or below the tank discharge fitting? I'm looking for a pattern here...
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Andrew Benjamin
Peg
How old is my what? I guess you mean pump. I bought the boat last year and I am pretty sure that the pump is not original equipment. I can't be sure (I am an hours drive from the dock) but I guess that the pump is just above or at the same level as the top of the tank. Maybe all I have to do is to drop the position of the pump as low as possible?? Over to you.
How old is my what? I guess you mean pump. I bought the boat last year and I am pretty sure that the pump is not original equipment. I can't be sure (I am an hours drive from the dock) but I guess that the pump is just above or at the same level as the top of the tank. Maybe all I have to do is to drop the position of the pump as low as possible?? Over to you.
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Peggie Hall/HeadMistress
You may be onto something, Andy...
Although the pump should be able to prime unless it's considerably above the tank and a considerable distance from it. All I can tell you from here is that something is causing the pump to suck air after you've sailed on that tack, even once you're level again. May be a failing diaphragm in the pump...may be where the water is settling in the tank...I can't tell you without seeing it. But I think you have enough now to know what to look for.
Although the pump should be able to prime unless it's considerably above the tank and a considerable distance from it. All I can tell you from here is that something is causing the pump to suck air after you've sailed on that tack, even once you're level again. May be a failing diaphragm in the pump...may be where the water is settling in the tank...I can't tell you without seeing it. But I think you have enough now to know what to look for.
If it's a Shurflo
Andy: If it is a Shurflo, you can return it to them for inspection and repair. I just did this on an older unit. They told me it was rebuildable but did not recommend it because it had a worn motor. It cost me the price of freight to find out that it was not worth the rebuild. If they are OK, they can do the repair for you. You can also buy a kit and find out yourself if it is worth rebuilding.
Andy: If it is a Shurflo, you can return it to them for inspection and repair. I just did this on an older unit. They told me it was rebuildable but did not recommend it because it had a worn motor. It cost me the price of freight to find out that it was not worth the rebuild. If they are OK, they can do the repair for you. You can also buy a kit and find out yourself if it is worth rebuilding.
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Alex G
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