Actually, our AC works fine, it's the sea-water pump system that's giving us trouble. I say system because the pump works quite well, just the sea-water flow keeps getting interrupted some how. Our stainer is empty every time I check it, the go through the process of purging the line and getting the pump going again. Tomorrow I'm going to tear apart the system and see if I can figure out the problem. I would gloriously welcome any suggestions. Here is a schematic of what I'm working with. I am wondering if I need to isolate the engine circuit, I installed the valve to shut off the ac circuit while underway, but I think maybe the siphon is being broken from the engine side.
!@#$! AC
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The vacuum breaker in the water line to the exhaust ell, or through the ell itself.. A test would be to put a valve in the line to the engine so you could isolate that side.. Going to be tough to remember to open that valve EVERY time to keep from frying the engine sea water pump and possibly the engine.. A dedicated thru hull may be in order??
Well this schematic of your A/C heat exchange system is the oddest thing I have seen in a while.
Not only does your A/C system share the engine cooling intake (that's bizarre enough) but you indicate that the sink is connected also? Is this a factory original setup or a PO debacle?
If you system is truly set up like this, I suspect that the A/C pump is pulling air from the sink and losing it's prime. I presume that the sink is a seawater faucet with a hand/foot pump. That pump could be leaking air through it's internal valves. Or, even more likely, when the sink pump is activated, it can pull water from the A/C loop and allow air to enter the sea water A/C pump. These pumps will not re-prime themselves.
I have a similar setup where my A/C intake and strainer feed the A/C pump and also a wash-down pump that supplies water to both my anchor locker (for wash-down) and to the galley faucet (rinsing dishes). In order to prevent the wash-down pump from pulling water out of the A/C loop I have a check valve in line with the A/C pump.
My engine cooling is entirely separate, as I believe is the best practice.
To test if the sink pump is sucking the A/C loop dry and causing the loss of prime should be easy. I suspect that this would occur when the A/ C pump is NOT running.
I suppose that the engine loop could be an air source also, but if that is the case, the air leak would have to be before the raw water pump. The raw water pump with it's rubber impeller would not allow air or water to be pulled from the engine heat exchanger which is down-stream from it.
Not only does your A/C system share the engine cooling intake (that's bizarre enough) but you indicate that the sink is connected also? Is this a factory original setup or a PO debacle?
If you system is truly set up like this, I suspect that the A/C pump is pulling air from the sink and losing it's prime. I presume that the sink is a seawater faucet with a hand/foot pump. That pump could be leaking air through it's internal valves. Or, even more likely, when the sink pump is activated, it can pull water from the A/C loop and allow air to enter the sea water A/C pump. These pumps will not re-prime themselves.
I have a similar setup where my A/C intake and strainer feed the A/C pump and also a wash-down pump that supplies water to both my anchor locker (for wash-down) and to the galley faucet (rinsing dishes). In order to prevent the wash-down pump from pulling water out of the A/C loop I have a check valve in line with the A/C pump.
My engine cooling is entirely separate, as I believe is the best practice.
To test if the sink pump is sucking the A/C loop dry and causing the loss of prime should be easy. I suspect that this would occur when the A/ C pump is NOT running.
I suppose that the engine loop could be an air source also, but if that is the case, the air leak would have to be before the raw water pump. The raw water pump with it's rubber impeller would not allow air or water to be pulled from the engine heat exchanger which is down-stream from it.
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I'm amazed that works at all. The A/C pump is going to find any reason, i.e., leak to lose prime and you have the mother of all leaks - the sink.
Was it working when you left the gulf coast?
I am thinking you may want to check the strainer gasket if it worked in Tx. and does not work in your new location. It would seem that the AC system should have it's own thru hull and you are probably experiencing the reason why.
I am thinking you may want to check the strainer gasket if it worked in Tx. and does not work in your new location. It would seem that the AC system should have it's own thru hull and you are probably experiencing the reason why.
KandD, I have to agree with Rich that that's some screwey set up. The only time I ever saw a similar system was on a much larger boat. They had a 2" thru-hull which fed directly into a huge manifold system. Then individual water lines led off that manifold to the engine, refrigeration, air-conditioning, etc. plus one small line to a foot pump at the galley. Each line off the manifold had it's own gate-valve.
I'd bet your system was not set up by Hunter but by a PO. One of the "tells" is that your a/c discharge tee's into the engine raw water discharge. I've got a '97 376 with factory installed a/c plus refrigeration and the discharge from each unit leads to it's own thru-hull with outlets just above the waterline, midship, starboard side. Among other things, I can check that they're functioning correctly when the compressor kicks in by just looking over the side to see whether there's water discharging.
I can't say with any certainty if your set-up is causing the problem but it certainly doesn't look like a correct installation.
I'd bet your system was not set up by Hunter but by a PO. One of the "tells" is that your a/c discharge tee's into the engine raw water discharge. I've got a '97 376 with factory installed a/c plus refrigeration and the discharge from each unit leads to it's own thru-hull with outlets just above the waterline, midship, starboard side. Among other things, I can check that they're functioning correctly when the compressor kicks in by just looking over the side to see whether there's water discharging.
I can't say with any certainty if your set-up is causing the problem but it certainly doesn't look like a correct installation.
mess
Hunter did not do something like this from the factory! This is a previous owners attempt to avoid installing additional thru-hulls and has bad news written all over it. Yeah, you can add shut offs, check valves ect...but all you're doing is putting duct tape on a bad idea. Engine and AC system really need to each have dedicated thru-hulls, intake strainers, seacocks and lines. As suggested, more than likely your sucking air and loosing prime through the sink. You might be able to get away with a one intake system like this if it was far enough below the waterline and you had a proper sea chest setup. Personally, I'd find a new home for the sink salt water intake or disconnect it for now and install a separate thru-hull strainer and seacock for the AC.
Hunter did not do something like this from the factory! This is a previous owners attempt to avoid installing additional thru-hulls and has bad news written all over it. Yeah, you can add shut offs, check valves ect...but all you're doing is putting duct tape on a bad idea. Engine and AC system really need to each have dedicated thru-hulls, intake strainers, seacocks and lines. As suggested, more than likely your sucking air and loosing prime through the sink. You might be able to get away with a one intake system like this if it was far enough below the waterline and you had a proper sea chest setup. Personally, I'd find a new home for the sink salt water intake or disconnect it for now and install a separate thru-hull strainer and seacock for the AC.
Thanks for the tips, I'm aware it's not factory and was done to eliminate below-water through hulls. We don't have a generator, so we won't be running the ac and engine at the same time. The ac T-s in just before it dumps overboard so I'm still able to look and see if it's running from the cockpit.
I'll pull the foot pump and see if that's the source of the vacuum break. I'll consider installing a dedicated through hull, but I REALLY like only having two seacocks to worry about (1 in and 1 out).
I'll pull the foot pump and see if that's the source of the vacuum break. I'll consider installing a dedicated through hull, but I REALLY like only having two seacocks to worry about (1 in and 1 out).
Yeah, fewer holes in the bottom of the boat
is better, but if you're still using the typically unsafe valve-screwed-directly-onto-the-throughhull arrangement that came from the factory then I'd suggest your concerns are misplaced.
Also, if you're using the original engine intake next to the shaft log (at least on the '85) there's no room to place a proper sea-cock. I just finished removing that one and relocating it to the bilge sump.
As to your issues, I'd imagine that you're getting a siphon break through the foot pump (if it's configured the same as mine.)
Also, even though you might be able to see a/c water exiting the exhaust discharge I'd be really nervous about unseen blockage pushing water back up into the muffler and engine.
With your current set-up you are far more likely to destroy a very expensive engine than you are to sink from properly installed seacocks.
is better, but if you're still using the typically unsafe valve-screwed-directly-onto-the-throughhull arrangement that came from the factory then I'd suggest your concerns are misplaced.
Also, if you're using the original engine intake next to the shaft log (at least on the '85) there's no room to place a proper sea-cock. I just finished removing that one and relocating it to the bilge sump.
As to your issues, I'd imagine that you're getting a siphon break through the foot pump (if it's configured the same as mine.)
Also, even though you might be able to see a/c water exiting the exhaust discharge I'd be really nervous about unseen blockage pushing water back up into the muffler and engine.
With your current set-up you are far more likely to destroy a very expensive engine than you are to sink from properly installed seacocks.
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Nope.
The sides of the sump actually are the top 8"-10" of the keel as viewed from the outside. The sump actually 'steps' down into the top center of the keel. This not only provides room for the sump itself but also provides some structure for the iron keel to bolt around rather than just onto (I think.)
If you drill outward from the sump you will go all the way through.
Oh, and by the way, the sides of the sump is just a liner. There is a small space and then the actual hull behind it. That's why in the attached pictures you see the seacock mounting disc seemingly recessed into a hole with a small gap around it. I drilled a 5" hole into the sump liner so I could glass the disc to the actual hull surface.
Building it this way allows any water behind the liner to get into the bilge quickly rather than stay bottled up and stagnant. It also allows me to fill the bilge with a detergent of my choosing to easily clean out the liner. Believe me, the water that came out of this space when I drilled the holes was far worse than any holding tank.
I have three seacocks in the bilge. One for each a/c unit, and now, one for the engine. I thought about t-ing the engine intake into an a/c intake with a valve but I knew one day I'd forget to turn the valve and would cook an impeller/engine. I'm having to idiot-proof Anthem because the captain, well, he's not as smart as he thinks he is . . .
The sides of the sump actually are the top 8"-10" of the keel as viewed from the outside. The sump actually 'steps' down into the top center of the keel. This not only provides room for the sump itself but also provides some structure for the iron keel to bolt around rather than just onto (I think.)
If you drill outward from the sump you will go all the way through.
Oh, and by the way, the sides of the sump is just a liner. There is a small space and then the actual hull behind it. That's why in the attached pictures you see the seacock mounting disc seemingly recessed into a hole with a small gap around it. I drilled a 5" hole into the sump liner so I could glass the disc to the actual hull surface.
Building it this way allows any water behind the liner to get into the bilge quickly rather than stay bottled up and stagnant. It also allows me to fill the bilge with a detergent of my choosing to easily clean out the liner. Believe me, the water that came out of this space when I drilled the holes was far worse than any holding tank.
I have three seacocks in the bilge. One for each a/c unit, and now, one for the engine. I thought about t-ing the engine intake into an a/c intake with a valve but I knew one day I'd forget to turn the valve and would cook an impeller/engine. I'm having to idiot-proof Anthem because the captain, well, he's not as smart as he thinks he is . . .
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knock on wood, but AC is trouble free for about 48 hrs now. I dove the boat and scraped out the through hull but didn't see too much. We weren't getting a whole lot of flow into the strainer so I back-blew the plumbing with our shop vac, dove it again and didn't see anything else... now it's working like a champ.
AC
Now that it seems to be working I'd take Rick's advice and at the minimum, install a separate discharge line for the AC. Since this can and should be above the waterline, you should be able to install one while the boat is in the water. (no swimming with the electric drill
) I'd put a shutoff valve on it someplace near or on the thru hull. You'll need to properly cap off the old AC discharge inlet into the exhaust.
Now that it seems to be working I'd take Rick's advice and at the minimum, install a separate discharge line for the AC. Since this can and should be above the waterline, you should be able to install one while the boat is in the water. (no swimming with the electric drill
) I'd put a shutoff valve on it someplace near or on the thru hull. You'll need to properly cap off the old AC discharge inlet into the exhaust.
I would at least do the discharge now. The boat doesn't have to be out of the water for that. This way you can see the water is coming out.
There is another good reason not to tee the A/C discharge into the engine discharge, even close to its exit, that has not yet been mentioned: With the engine off and the A/C working it is possible for the water to back-flow into the engine, causing a huge expense to overhaul it. I would strongly recommend re-routing the A/C discharge IMMEDIATELY to a direct, above waterline, thruhull.
The surveyor didn't seem to have issues, and actually liked the reduced number of through hulls. His experience was with commercial vessels and came highly recommended, so we trust him. The through-hull is above the water line and the T is directly above it, so a substantial clog and back-flow would be required. I believe the big issue is the hose diameter from the AC steps down quite a bit, which seems to be causing the issue with the pump (when there aren't jellies and tunicates in the strainer).
Excuse me, but just because someone is an expert in commercial vessel does not necessarily make them qualified for pleasure boat or better yet a sailboat.
I don't think you would let your foot doctor operate on your eye. I have seen some sailboat reviews by a noted surveyor that knows quite a bit about powerboats, but I would not let him look at a sailboat that I am considering purchasing.
Just my opinion. I would listen to the sailor on this site regarding your plumbing. It does not appear that what you have is considered "normal".
It is your boat and your decisions so you need to decide.
I don't think you would let your foot doctor operate on your eye. I have seen some sailboat reviews by a noted surveyor that knows quite a bit about powerboats, but I would not let him look at a sailboat that I am considering purchasing.
Just my opinion. I would listen to the sailor on this site regarding your plumbing. It does not appear that what you have is considered "normal".
It is your boat and your decisions so you need to decide.
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